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Home / DTC / P1238 — Manufacturer-Specific Powertrain Fault (P1238)

P1238 — Manufacturer-Specific Powertrain Fault (P1238)

Detailed page for trouble code P1238.

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Code

P1238

AUDI P — Powertrain

Manufacturer-Specific Powertrain Fault (P1238)

Brand: AUDI
Type: P — Powertrain
AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • Open or shorted wiring in the monitored circuit
  • Corroded, loose or damaged connector or ground
  • Failed sensor or actuator associated with the monitored circuit
  • Faulty fuse, relay or power supply to the circuit
  • Intermittent fault caused by vibration or heat (broken wire or pin)
  • Faulty ECM or control module software/calibration

Symptoms

  • Malfunction indicator lamp (MIL) illuminated
  • Reduced engine performance or limp mode (if ECM limits functions)
  • Rough idle, hesitation or misfire-like symptoms
  • Hard starting or no-start in some cases
  • Degraded fuel economy or drivability issues
  • Intermittent faults that appear under specific conditions (temperature, load)

What to check

  • Read and record all stored codes and freeze frame data with a professional scan tool
  • Check for related manufacturer-specific codes that may point to subsystem
  • Inspect wiring harness and connectors at the suspected sensor/actuator for corrosion, damage or loose pins
  • Verify battery voltage and main grounds; low supply can cause false codes
  • Check fuses and relays that feed the suspect circuit
  • Perform wiggle test while monitoring relevant live data for intermittent changes

Signal parameters

  • Most sensor reference voltages: 5.0 V reference and ground present (measure at sensor connector)
  • Typical sensor signal range: 0–5.0 V (varies by sensor type)
  • CAN bus nominal idle voltage ~2.5 V (verify network communications if code references messages)
  • PWM actuators: duty cycle 0–100% and frequencies from tens to thousands of Hz (measure with scope)
  • Resistance checks: expected Ohms vary by component — consult OEM specs before replacing

Diagnostic algorithm

  1. Connect a capable OEM‑level or pro scan tool; read all DTCs and freeze frame. Note conditions when code set (RPM, load, temp, voltage).
  2. Check for technical service bulletins (TSBs) or software updates for P1238 on the specific Audi model/year.
  3. Visually inspect related harnesses, connectors and grounds; repair any physical damage. Ensure connectors are fully seated and pins straight.
  4. Verify power and ground at the suspect sensor/actuator connector with ignition on; compare to OEM reference voltages.
  5. Backprobe the signal wire while monitoring live data; verify signal behaves within expected range under varying engine conditions. Use oscilloscope for PWM or noisy signals.
  6. Check fuses and relays that supply the circuit; replace if suspect. Perform relay swap test if applicable.
  7. Perform continuity and resistance checks on wiring between sensor and ECM; repair any open/short. Wiggle harness while monitoring for intermittent faults.
  8. If wiring and power/grounds are good, substitute a known‑good sensor or actuator (if available) or bench‑test the component to confirm failure.
  9. If component replacement fixes the fault, clear codes and road test to verify. If issue persists and wiring/component good, consider ECM diagnosis or reflash by dealer/authorized shop.
  10. Document repairs and retest; if intermittent, leave vehicle for extended road test or install data logger to capture failing conditions.

Likely causes

  • Damaged wiring/connector (water ingress, chafing)
  • Failed sensor or actuator in the monitored circuit
  • Bad ground or supply voltage to sensor/actuator
  • Blown fuse or bad relay feeding the circuit
  • Intermittent connector contact or pin damage

Fault status

⚠️ Status
Manufacturer‑specific powertrain fault detected (P1238). ECM observed an abnormal signal; further diagnosis of circuit, sensor/actuator, wiring, power/ground or control module required.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 0.8-2.5 hours

Similar codes

P1237 P1239 P1240 P0190 P0230 P0300
Repair manuals

Manual library for AUDI

1,243

Browse 1,243 AUDI manuals: repair procedures, diagnostics, wiring diagrams, component locations, service data and Labor Times by year, model and trim.

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Code

P1238

FORD P — Powertrain

Fuel Pump Secondary Circuit Fault

Brand: FORD
Type: P — Powertrain
AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • Open or shorted wiring in the monitored circuit
  • Corroded, loose or damaged connector or ground
  • Failed sensor or actuator associated with the monitored circuit
  • Faulty fuse, relay or power supply to the circuit
  • Intermittent fault caused by vibration or heat (broken wire or pin)
  • Faulty ECM or control module software/calibration

Symptoms

  • Malfunction indicator lamp (MIL) illuminated
  • Reduced engine performance or limp mode (if ECM limits functions)
  • Rough idle, hesitation or misfire-like symptoms
  • Hard starting or no-start in some cases
  • Degraded fuel economy or drivability issues
  • Intermittent faults that appear under specific conditions (temperature, load)

What to check

  • Read and record all stored codes and freeze frame data with a professional scan tool
  • Check for related manufacturer-specific codes that may point to subsystem
  • Inspect wiring harness and connectors at the suspected sensor/actuator for corrosion, damage or loose pins
  • Verify battery voltage and main grounds; low supply can cause false codes
  • Check fuses and relays that feed the suspect circuit
  • Perform wiggle test while monitoring relevant live data for intermittent changes

Signal parameters

  • Most sensor reference voltages: 5.0 V reference and ground present (measure at sensor connector)
  • Typical sensor signal range: 0–5.0 V (varies by sensor type)
  • CAN bus nominal idle voltage ~2.5 V (verify network communications if code references messages)
  • PWM actuators: duty cycle 0–100% and frequencies from tens to thousands of Hz (measure with scope)
  • Resistance checks: expected Ohms vary by component — consult OEM specs before replacing

Diagnostic algorithm

  1. Connect a capable OEM‑level or pro scan tool; read all DTCs and freeze frame. Note conditions when code set (RPM, load, temp, voltage).
  2. Check for technical service bulletins (TSBs) or software updates for P1238 on the specific Audi model/year.
  3. Visually inspect related harnesses, connectors and grounds; repair any physical damage. Ensure connectors are fully seated and pins straight.
  4. Verify power and ground at the suspect sensor/actuator connector with ignition on; compare to OEM reference voltages.
  5. Backprobe the signal wire while monitoring live data; verify signal behaves within expected range under varying engine conditions. Use oscilloscope for PWM or noisy signals.
  6. Check fuses and relays that supply the circuit; replace if suspect. Perform relay swap test if applicable.
  7. Perform continuity and resistance checks on wiring between sensor and ECM; repair any open/short. Wiggle harness while monitoring for intermittent faults.
  8. If wiring and power/grounds are good, substitute a known‑good sensor or actuator (if available) or bench‑test the component to confirm failure.
  9. If component replacement fixes the fault, clear codes and road test to verify. If issue persists and wiring/component good, consider ECM diagnosis or reflash by dealer/authorized shop.
  10. Document repairs and retest; if intermittent, leave vehicle for extended road test or install data logger to capture failing conditions.

Likely causes

  • Damaged wiring/connector (water ingress, chafing)
  • Failed sensor or actuator in the monitored circuit
  • Bad ground or supply voltage to sensor/actuator
  • Blown fuse or bad relay feeding the circuit
  • Intermittent connector contact or pin damage

Fault status

⚠️ Status
Manufacturer‑specific powertrain fault detected (P1238). ECM observed an abnormal signal; further diagnosis of circuit, sensor/actuator, wiring, power/ground or control module required.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 0.8-2.5 hours

Similar codes

P1237 P1239 P1240 P0190 P0230 P0300
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Code

P1238

JAGUAR P — Powertrain

VSV 3 Circuit

Brand: JAGUAR
Type: P — Powertrain
AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • Open or shorted wiring in the monitored circuit
  • Corroded, loose or damaged connector or ground
  • Failed sensor or actuator associated with the monitored circuit
  • Faulty fuse, relay or power supply to the circuit
  • Intermittent fault caused by vibration or heat (broken wire or pin)
  • Faulty ECM or control module software/calibration

Symptoms

  • Malfunction indicator lamp (MIL) illuminated
  • Reduced engine performance or limp mode (if ECM limits functions)
  • Rough idle, hesitation or misfire-like symptoms
  • Hard starting or no-start in some cases
  • Degraded fuel economy or drivability issues
  • Intermittent faults that appear under specific conditions (temperature, load)

What to check

  • Read and record all stored codes and freeze frame data with a professional scan tool
  • Check for related manufacturer-specific codes that may point to subsystem
  • Inspect wiring harness and connectors at the suspected sensor/actuator for corrosion, damage or loose pins
  • Verify battery voltage and main grounds; low supply can cause false codes
  • Check fuses and relays that feed the suspect circuit
  • Perform wiggle test while monitoring relevant live data for intermittent changes

Signal parameters

  • Most sensor reference voltages: 5.0 V reference and ground present (measure at sensor connector)
  • Typical sensor signal range: 0–5.0 V (varies by sensor type)
  • CAN bus nominal idle voltage ~2.5 V (verify network communications if code references messages)
  • PWM actuators: duty cycle 0–100% and frequencies from tens to thousands of Hz (measure with scope)
  • Resistance checks: expected Ohms vary by component — consult OEM specs before replacing

Diagnostic algorithm

  1. Connect a capable OEM‑level or pro scan tool; read all DTCs and freeze frame. Note conditions when code set (RPM, load, temp, voltage).
  2. Check for technical service bulletins (TSBs) or software updates for P1238 on the specific Audi model/year.
  3. Visually inspect related harnesses, connectors and grounds; repair any physical damage. Ensure connectors are fully seated and pins straight.
  4. Verify power and ground at the suspect sensor/actuator connector with ignition on; compare to OEM reference voltages.
  5. Backprobe the signal wire while monitoring live data; verify signal behaves within expected range under varying engine conditions. Use oscilloscope for PWM or noisy signals.
  6. Check fuses and relays that supply the circuit; replace if suspect. Perform relay swap test if applicable.
  7. Perform continuity and resistance checks on wiring between sensor and ECM; repair any open/short. Wiggle harness while monitoring for intermittent faults.
  8. If wiring and power/grounds are good, substitute a known‑good sensor or actuator (if available) or bench‑test the component to confirm failure.
  9. If component replacement fixes the fault, clear codes and road test to verify. If issue persists and wiring/component good, consider ECM diagnosis or reflash by dealer/authorized shop.
  10. Document repairs and retest; if intermittent, leave vehicle for extended road test or install data logger to capture failing conditions.

Likely causes

  • Damaged wiring/connector (water ingress, chafing)
  • Failed sensor or actuator in the monitored circuit
  • Bad ground or supply voltage to sensor/actuator
  • Blown fuse or bad relay feeding the circuit
  • Intermittent connector contact or pin damage

Fault status

⚠️ Status
Manufacturer‑specific powertrain fault detected (P1238). ECM observed an abnormal signal; further diagnosis of circuit, sensor/actuator, wiring, power/ground or control module required.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 0.8-2.5 hours

Similar codes

P1237 P1239 P1240 P0190 P0230 P0300
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Keep it short and practical. Up to 500 characters.
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Code

P1238

LAND ROVER P — Powertrain

Vacuum switching valve 3 circuit malfunction

Brand: LAND ROVER
Type: P — Powertrain
AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • Open or shorted wiring in the monitored circuit
  • Corroded, loose or damaged connector or ground
  • Failed sensor or actuator associated with the monitored circuit
  • Faulty fuse, relay or power supply to the circuit
  • Intermittent fault caused by vibration or heat (broken wire or pin)
  • Faulty ECM or control module software/calibration

Symptoms

  • Malfunction indicator lamp (MIL) illuminated
  • Reduced engine performance or limp mode (if ECM limits functions)
  • Rough idle, hesitation or misfire-like symptoms
  • Hard starting or no-start in some cases
  • Degraded fuel economy or drivability issues
  • Intermittent faults that appear under specific conditions (temperature, load)

What to check

  • Read and record all stored codes and freeze frame data with a professional scan tool
  • Check for related manufacturer-specific codes that may point to subsystem
  • Inspect wiring harness and connectors at the suspected sensor/actuator for corrosion, damage or loose pins
  • Verify battery voltage and main grounds; low supply can cause false codes
  • Check fuses and relays that feed the suspect circuit
  • Perform wiggle test while monitoring relevant live data for intermittent changes

Signal parameters

  • Most sensor reference voltages: 5.0 V reference and ground present (measure at sensor connector)
  • Typical sensor signal range: 0–5.0 V (varies by sensor type)
  • CAN bus nominal idle voltage ~2.5 V (verify network communications if code references messages)
  • PWM actuators: duty cycle 0–100% and frequencies from tens to thousands of Hz (measure with scope)
  • Resistance checks: expected Ohms vary by component — consult OEM specs before replacing

Diagnostic algorithm

  1. Connect a capable OEM‑level or pro scan tool; read all DTCs and freeze frame. Note conditions when code set (RPM, load, temp, voltage).
  2. Check for technical service bulletins (TSBs) or software updates for P1238 on the specific Audi model/year.
  3. Visually inspect related harnesses, connectors and grounds; repair any physical damage. Ensure connectors are fully seated and pins straight.
  4. Verify power and ground at the suspect sensor/actuator connector with ignition on; compare to OEM reference voltages.
  5. Backprobe the signal wire while monitoring live data; verify signal behaves within expected range under varying engine conditions. Use oscilloscope for PWM or noisy signals.
  6. Check fuses and relays that supply the circuit; replace if suspect. Perform relay swap test if applicable.
  7. Perform continuity and resistance checks on wiring between sensor and ECM; repair any open/short. Wiggle harness while monitoring for intermittent faults.
  8. If wiring and power/grounds are good, substitute a known‑good sensor or actuator (if available) or bench‑test the component to confirm failure.
  9. If component replacement fixes the fault, clear codes and road test to verify. If issue persists and wiring/component good, consider ECM diagnosis or reflash by dealer/authorized shop.
  10. Document repairs and retest; if intermittent, leave vehicle for extended road test or install data logger to capture failing conditions.

Likely causes

  • Damaged wiring/connector (water ingress, chafing)
  • Failed sensor or actuator in the monitored circuit
  • Bad ground or supply voltage to sensor/actuator
  • Blown fuse or bad relay feeding the circuit
  • Intermittent connector contact or pin damage

Fault status

⚠️ Status
Manufacturer‑specific powertrain fault detected (P1238). ECM observed an abnormal signal; further diagnosis of circuit, sensor/actuator, wiring, power/ground or control module required.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 0.8-2.5 hours

Similar codes

P1237 P1239 P1240 P0190 P0230 P0300
413

Browse 413 LAND ROVER manuals: repair procedures, diagnostics, wiring diagrams, component locations, service data and Labor Times by year, model and trim.

LAND ROVER

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+100 karma for a short comment :)
Keep it short and practical. Up to 500 characters.
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Code

P1238

LINCOLN P — Powertrain

Fuel Pump Secondary Circuit Fault

Brand: LINCOLN
Type: P — Powertrain
AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • Open or shorted wiring in the monitored circuit
  • Corroded, loose or damaged connector or ground
  • Failed sensor or actuator associated with the monitored circuit
  • Faulty fuse, relay or power supply to the circuit
  • Intermittent fault caused by vibration or heat (broken wire or pin)
  • Faulty ECM or control module software/calibration

Symptoms

  • Malfunction indicator lamp (MIL) illuminated
  • Reduced engine performance or limp mode (if ECM limits functions)
  • Rough idle, hesitation or misfire-like symptoms
  • Hard starting or no-start in some cases
  • Degraded fuel economy or drivability issues
  • Intermittent faults that appear under specific conditions (temperature, load)

What to check

  • Read and record all stored codes and freeze frame data with a professional scan tool
  • Check for related manufacturer-specific codes that may point to subsystem
  • Inspect wiring harness and connectors at the suspected sensor/actuator for corrosion, damage or loose pins
  • Verify battery voltage and main grounds; low supply can cause false codes
  • Check fuses and relays that feed the suspect circuit
  • Perform wiggle test while monitoring relevant live data for intermittent changes

Signal parameters

  • Most sensor reference voltages: 5.0 V reference and ground present (measure at sensor connector)
  • Typical sensor signal range: 0–5.0 V (varies by sensor type)
  • CAN bus nominal idle voltage ~2.5 V (verify network communications if code references messages)
  • PWM actuators: duty cycle 0–100% and frequencies from tens to thousands of Hz (measure with scope)
  • Resistance checks: expected Ohms vary by component — consult OEM specs before replacing

Diagnostic algorithm

  1. Connect a capable OEM‑level or pro scan tool; read all DTCs and freeze frame. Note conditions when code set (RPM, load, temp, voltage).
  2. Check for technical service bulletins (TSBs) or software updates for P1238 on the specific Audi model/year.
  3. Visually inspect related harnesses, connectors and grounds; repair any physical damage. Ensure connectors are fully seated and pins straight.
  4. Verify power and ground at the suspect sensor/actuator connector with ignition on; compare to OEM reference voltages.
  5. Backprobe the signal wire while monitoring live data; verify signal behaves within expected range under varying engine conditions. Use oscilloscope for PWM or noisy signals.
  6. Check fuses and relays that supply the circuit; replace if suspect. Perform relay swap test if applicable.
  7. Perform continuity and resistance checks on wiring between sensor and ECM; repair any open/short. Wiggle harness while monitoring for intermittent faults.
  8. If wiring and power/grounds are good, substitute a known‑good sensor or actuator (if available) or bench‑test the component to confirm failure.
  9. If component replacement fixes the fault, clear codes and road test to verify. If issue persists and wiring/component good, consider ECM diagnosis or reflash by dealer/authorized shop.
  10. Document repairs and retest; if intermittent, leave vehicle for extended road test or install data logger to capture failing conditions.

Likely causes

  • Damaged wiring/connector (water ingress, chafing)
  • Failed sensor or actuator in the monitored circuit
  • Bad ground or supply voltage to sensor/actuator
  • Blown fuse or bad relay feeding the circuit
  • Intermittent connector contact or pin damage

Fault status

⚠️ Status
Manufacturer‑specific powertrain fault detected (P1238). ECM observed an abnormal signal; further diagnosis of circuit, sensor/actuator, wiring, power/ground or control module required.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 0.8-2.5 hours

Similar codes

P1237 P1239 P1240 P0190 P0230 P0300
166

Browse 166 LINCOLN manuals: repair procedures, diagnostics, wiring diagrams, component locations, service data and Labor Times by year, model and trim.

LINCOLN

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+100 karma for a short comment :)
Keep it short and practical. Up to 500 characters.
Send to email
Code

P1238

MERCURY P — Powertrain

Fuel Pump Secondary Circuit Fault

Brand: MERCURY
Type: P — Powertrain
AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • Open or shorted wiring in the monitored circuit
  • Corroded, loose or damaged connector or ground
  • Failed sensor or actuator associated with the monitored circuit
  • Faulty fuse, relay or power supply to the circuit
  • Intermittent fault caused by vibration or heat (broken wire or pin)
  • Faulty ECM or control module software/calibration

Symptoms

  • Malfunction indicator lamp (MIL) illuminated
  • Reduced engine performance or limp mode (if ECM limits functions)
  • Rough idle, hesitation or misfire-like symptoms
  • Hard starting or no-start in some cases
  • Degraded fuel economy or drivability issues
  • Intermittent faults that appear under specific conditions (temperature, load)

What to check

  • Read and record all stored codes and freeze frame data with a professional scan tool
  • Check for related manufacturer-specific codes that may point to subsystem
  • Inspect wiring harness and connectors at the suspected sensor/actuator for corrosion, damage or loose pins
  • Verify battery voltage and main grounds; low supply can cause false codes
  • Check fuses and relays that feed the suspect circuit
  • Perform wiggle test while monitoring relevant live data for intermittent changes

Signal parameters

  • Most sensor reference voltages: 5.0 V reference and ground present (measure at sensor connector)
  • Typical sensor signal range: 0–5.0 V (varies by sensor type)
  • CAN bus nominal idle voltage ~2.5 V (verify network communications if code references messages)
  • PWM actuators: duty cycle 0–100% and frequencies from tens to thousands of Hz (measure with scope)
  • Resistance checks: expected Ohms vary by component — consult OEM specs before replacing

Diagnostic algorithm

  1. Connect a capable OEM‑level or pro scan tool; read all DTCs and freeze frame. Note conditions when code set (RPM, load, temp, voltage).
  2. Check for technical service bulletins (TSBs) or software updates for P1238 on the specific Audi model/year.
  3. Visually inspect related harnesses, connectors and grounds; repair any physical damage. Ensure connectors are fully seated and pins straight.
  4. Verify power and ground at the suspect sensor/actuator connector with ignition on; compare to OEM reference voltages.
  5. Backprobe the signal wire while monitoring live data; verify signal behaves within expected range under varying engine conditions. Use oscilloscope for PWM or noisy signals.
  6. Check fuses and relays that supply the circuit; replace if suspect. Perform relay swap test if applicable.
  7. Perform continuity and resistance checks on wiring between sensor and ECM; repair any open/short. Wiggle harness while monitoring for intermittent faults.
  8. If wiring and power/grounds are good, substitute a known‑good sensor or actuator (if available) or bench‑test the component to confirm failure.
  9. If component replacement fixes the fault, clear codes and road test to verify. If issue persists and wiring/component good, consider ECM diagnosis or reflash by dealer/authorized shop.
  10. Document repairs and retest; if intermittent, leave vehicle for extended road test or install data logger to capture failing conditions.

Likely causes

  • Damaged wiring/connector (water ingress, chafing)
  • Failed sensor or actuator in the monitored circuit
  • Bad ground or supply voltage to sensor/actuator
  • Blown fuse or bad relay feeding the circuit
  • Intermittent connector contact or pin damage

Fault status

⚠️ Status
Manufacturer‑specific powertrain fault detected (P1238). ECM observed an abnormal signal; further diagnosis of circuit, sensor/actuator, wiring, power/ground or control module required.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 0.8-2.5 hours

Similar codes

P1237 P1239 P1240 P0190 P0230 P0300
296

Browse 296 MERCURY manuals: repair procedures, diagnostics, wiring diagrams, component locations, service data and Labor Times by year, model and trim.

MERCURY

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+100 karma for a short comment :)
Keep it short and practical. Up to 500 characters.
Send to email
Code

P1238

MINI P — Powertrain

Manifold absolute pressure (MAP) sensor 2 - high input

Brand: MINI
Type: P — Powertrain
AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • Open or shorted wiring in the monitored circuit
  • Corroded, loose or damaged connector or ground
  • Failed sensor or actuator associated with the monitored circuit
  • Faulty fuse, relay or power supply to the circuit
  • Intermittent fault caused by vibration or heat (broken wire or pin)
  • Faulty ECM or control module software/calibration

Symptoms

  • Malfunction indicator lamp (MIL) illuminated
  • Reduced engine performance or limp mode (if ECM limits functions)
  • Rough idle, hesitation or misfire-like symptoms
  • Hard starting or no-start in some cases
  • Degraded fuel economy or drivability issues
  • Intermittent faults that appear under specific conditions (temperature, load)

What to check

  • Read and record all stored codes and freeze frame data with a professional scan tool
  • Check for related manufacturer-specific codes that may point to subsystem
  • Inspect wiring harness and connectors at the suspected sensor/actuator for corrosion, damage or loose pins
  • Verify battery voltage and main grounds; low supply can cause false codes
  • Check fuses and relays that feed the suspect circuit
  • Perform wiggle test while monitoring relevant live data for intermittent changes

Signal parameters

  • Most sensor reference voltages: 5.0 V reference and ground present (measure at sensor connector)
  • Typical sensor signal range: 0–5.0 V (varies by sensor type)
  • CAN bus nominal idle voltage ~2.5 V (verify network communications if code references messages)
  • PWM actuators: duty cycle 0–100% and frequencies from tens to thousands of Hz (measure with scope)
  • Resistance checks: expected Ohms vary by component — consult OEM specs before replacing

Diagnostic algorithm

  1. Connect a capable OEM‑level or pro scan tool; read all DTCs and freeze frame. Note conditions when code set (RPM, load, temp, voltage).
  2. Check for technical service bulletins (TSBs) or software updates for P1238 on the specific Audi model/year.
  3. Visually inspect related harnesses, connectors and grounds; repair any physical damage. Ensure connectors are fully seated and pins straight.
  4. Verify power and ground at the suspect sensor/actuator connector with ignition on; compare to OEM reference voltages.
  5. Backprobe the signal wire while monitoring live data; verify signal behaves within expected range under varying engine conditions. Use oscilloscope for PWM or noisy signals.
  6. Check fuses and relays that supply the circuit; replace if suspect. Perform relay swap test if applicable.
  7. Perform continuity and resistance checks on wiring between sensor and ECM; repair any open/short. Wiggle harness while monitoring for intermittent faults.
  8. If wiring and power/grounds are good, substitute a known‑good sensor or actuator (if available) or bench‑test the component to confirm failure.
  9. If component replacement fixes the fault, clear codes and road test to verify. If issue persists and wiring/component good, consider ECM diagnosis or reflash by dealer/authorized shop.
  10. Document repairs and retest; if intermittent, leave vehicle for extended road test or install data logger to capture failing conditions.

Likely causes

  • Damaged wiring/connector (water ingress, chafing)
  • Failed sensor or actuator in the monitored circuit
  • Bad ground or supply voltage to sensor/actuator
  • Blown fuse or bad relay feeding the circuit
  • Intermittent connector contact or pin damage

Fault status

⚠️ Status
Manufacturer‑specific powertrain fault detected (P1238). ECM observed an abnormal signal; further diagnosis of circuit, sensor/actuator, wiring, power/ground or control module required.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 0.8-2.5 hours

Similar codes

P1237 P1239 P1240 P0190 P0230 P0300
Your experience will help others
+100 karma for a short comment :)
Keep it short and practical. Up to 500 characters.
Send to email
Code

P1238

MITSUBISHI P — Powertrain

AFS plausibility(torque monitor)

Brand: MITSUBISHI
Type: P — Powertrain
AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • Open or shorted wiring in the monitored circuit
  • Corroded, loose or damaged connector or ground
  • Failed sensor or actuator associated with the monitored circuit
  • Faulty fuse, relay or power supply to the circuit
  • Intermittent fault caused by vibration or heat (broken wire or pin)
  • Faulty ECM or control module software/calibration

Symptoms

  • Malfunction indicator lamp (MIL) illuminated
  • Reduced engine performance or limp mode (if ECM limits functions)
  • Rough idle, hesitation or misfire-like symptoms
  • Hard starting or no-start in some cases
  • Degraded fuel economy or drivability issues
  • Intermittent faults that appear under specific conditions (temperature, load)

What to check

  • Read and record all stored codes and freeze frame data with a professional scan tool
  • Check for related manufacturer-specific codes that may point to subsystem
  • Inspect wiring harness and connectors at the suspected sensor/actuator for corrosion, damage or loose pins
  • Verify battery voltage and main grounds; low supply can cause false codes
  • Check fuses and relays that feed the suspect circuit
  • Perform wiggle test while monitoring relevant live data for intermittent changes

Signal parameters

  • Most sensor reference voltages: 5.0 V reference and ground present (measure at sensor connector)
  • Typical sensor signal range: 0–5.0 V (varies by sensor type)
  • CAN bus nominal idle voltage ~2.5 V (verify network communications if code references messages)
  • PWM actuators: duty cycle 0–100% and frequencies from tens to thousands of Hz (measure with scope)
  • Resistance checks: expected Ohms vary by component — consult OEM specs before replacing

Diagnostic algorithm

  1. Connect a capable OEM‑level or pro scan tool; read all DTCs and freeze frame. Note conditions when code set (RPM, load, temp, voltage).
  2. Check for technical service bulletins (TSBs) or software updates for P1238 on the specific Audi model/year.
  3. Visually inspect related harnesses, connectors and grounds; repair any physical damage. Ensure connectors are fully seated and pins straight.
  4. Verify power and ground at the suspect sensor/actuator connector with ignition on; compare to OEM reference voltages.
  5. Backprobe the signal wire while monitoring live data; verify signal behaves within expected range under varying engine conditions. Use oscilloscope for PWM or noisy signals.
  6. Check fuses and relays that supply the circuit; replace if suspect. Perform relay swap test if applicable.
  7. Perform continuity and resistance checks on wiring between sensor and ECM; repair any open/short. Wiggle harness while monitoring for intermittent faults.
  8. If wiring and power/grounds are good, substitute a known‑good sensor or actuator (if available) or bench‑test the component to confirm failure.
  9. If component replacement fixes the fault, clear codes and road test to verify. If issue persists and wiring/component good, consider ECM diagnosis or reflash by dealer/authorized shop.
  10. Document repairs and retest; if intermittent, leave vehicle for extended road test or install data logger to capture failing conditions.

Likely causes

  • Damaged wiring/connector (water ingress, chafing)
  • Failed sensor or actuator in the monitored circuit
  • Bad ground or supply voltage to sensor/actuator
  • Blown fuse or bad relay feeding the circuit
  • Intermittent connector contact or pin damage

Fault status

⚠️ Status
Manufacturer‑specific powertrain fault detected (P1238). ECM observed an abnormal signal; further diagnosis of circuit, sensor/actuator, wiring, power/ground or control module required.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 0.8-2.5 hours

Similar codes

P1237 P1239 P1240 P0190 P0230 P0300
406

Browse 406 MITSUBISHI manuals: repair procedures, diagnostics, wiring diagrams, component locations, service data and Labor Times by year, model and trim.

MITSUBISHI

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Code

P1238

Other P — Powertrain

Fuel Pump Secondary Circuit Malfunction

Brand: Other
Type: P — Powertrain
AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • Open or shorted wiring in the monitored circuit
  • Corroded, loose or damaged connector or ground
  • Failed sensor or actuator associated with the monitored circuit
  • Faulty fuse, relay or power supply to the circuit
  • Intermittent fault caused by vibration or heat (broken wire or pin)
  • Faulty ECM or control module software/calibration

Symptoms

  • Malfunction indicator lamp (MIL) illuminated
  • Reduced engine performance or limp mode (if ECM limits functions)
  • Rough idle, hesitation or misfire-like symptoms
  • Hard starting or no-start in some cases
  • Degraded fuel economy or drivability issues
  • Intermittent faults that appear under specific conditions (temperature, load)

What to check

  • Read and record all stored codes and freeze frame data with a professional scan tool
  • Check for related manufacturer-specific codes that may point to subsystem
  • Inspect wiring harness and connectors at the suspected sensor/actuator for corrosion, damage or loose pins
  • Verify battery voltage and main grounds; low supply can cause false codes
  • Check fuses and relays that feed the suspect circuit
  • Perform wiggle test while monitoring relevant live data for intermittent changes

Signal parameters

  • Most sensor reference voltages: 5.0 V reference and ground present (measure at sensor connector)
  • Typical sensor signal range: 0–5.0 V (varies by sensor type)
  • CAN bus nominal idle voltage ~2.5 V (verify network communications if code references messages)
  • PWM actuators: duty cycle 0–100% and frequencies from tens to thousands of Hz (measure with scope)
  • Resistance checks: expected Ohms vary by component — consult OEM specs before replacing

Diagnostic algorithm

  1. Connect a capable OEM‑level or pro scan tool; read all DTCs and freeze frame. Note conditions when code set (RPM, load, temp, voltage).
  2. Check for technical service bulletins (TSBs) or software updates for P1238 on the specific Audi model/year.
  3. Visually inspect related harnesses, connectors and grounds; repair any physical damage. Ensure connectors are fully seated and pins straight.
  4. Verify power and ground at the suspect sensor/actuator connector with ignition on; compare to OEM reference voltages.
  5. Backprobe the signal wire while monitoring live data; verify signal behaves within expected range under varying engine conditions. Use oscilloscope for PWM or noisy signals.
  6. Check fuses and relays that supply the circuit; replace if suspect. Perform relay swap test if applicable.
  7. Perform continuity and resistance checks on wiring between sensor and ECM; repair any open/short. Wiggle harness while monitoring for intermittent faults.
  8. If wiring and power/grounds are good, substitute a known‑good sensor or actuator (if available) or bench‑test the component to confirm failure.
  9. If component replacement fixes the fault, clear codes and road test to verify. If issue persists and wiring/component good, consider ECM diagnosis or reflash by dealer/authorized shop.
  10. Document repairs and retest; if intermittent, leave vehicle for extended road test or install data logger to capture failing conditions.

Likely causes

  • Damaged wiring/connector (water ingress, chafing)
  • Failed sensor or actuator in the monitored circuit
  • Bad ground or supply voltage to sensor/actuator
  • Blown fuse or bad relay feeding the circuit
  • Intermittent connector contact or pin damage

Fault status

⚠️ Status
Manufacturer‑specific powertrain fault detected (P1238). ECM observed an abnormal signal; further diagnosis of circuit, sensor/actuator, wiring, power/ground or control module required.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 0.8-2.5 hours

Similar codes

P1237 P1239 P1240 P0190 P0230 P0300
9,688

The library contains 9,688 repair and diagnostic manuals. Choose a brand to open the full manual tree by year, model and trim.

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89
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479
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206
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456
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75
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155
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413
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626
VOLVO
221
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Code

P1238

PORSCHE P — Powertrain

Fuel injector, cylinder 2

Brand: PORSCHE
Type: P — Powertrain
AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • Open or shorted wiring in the monitored circuit
  • Corroded, loose or damaged connector or ground
  • Failed sensor or actuator associated with the monitored circuit
  • Faulty fuse, relay or power supply to the circuit
  • Intermittent fault caused by vibration or heat (broken wire or pin)
  • Faulty ECM or control module software/calibration

Symptoms

  • Malfunction indicator lamp (MIL) illuminated
  • Reduced engine performance or limp mode (if ECM limits functions)
  • Rough idle, hesitation or misfire-like symptoms
  • Hard starting or no-start in some cases
  • Degraded fuel economy or drivability issues
  • Intermittent faults that appear under specific conditions (temperature, load)

What to check

  • Read and record all stored codes and freeze frame data with a professional scan tool
  • Check for related manufacturer-specific codes that may point to subsystem
  • Inspect wiring harness and connectors at the suspected sensor/actuator for corrosion, damage or loose pins
  • Verify battery voltage and main grounds; low supply can cause false codes
  • Check fuses and relays that feed the suspect circuit
  • Perform wiggle test while monitoring relevant live data for intermittent changes

Signal parameters

  • Most sensor reference voltages: 5.0 V reference and ground present (measure at sensor connector)
  • Typical sensor signal range: 0–5.0 V (varies by sensor type)
  • CAN bus nominal idle voltage ~2.5 V (verify network communications if code references messages)
  • PWM actuators: duty cycle 0–100% and frequencies from tens to thousands of Hz (measure with scope)
  • Resistance checks: expected Ohms vary by component — consult OEM specs before replacing

Diagnostic algorithm

  1. Connect a capable OEM‑level or pro scan tool; read all DTCs and freeze frame. Note conditions when code set (RPM, load, temp, voltage).
  2. Check for technical service bulletins (TSBs) or software updates for P1238 on the specific Audi model/year.
  3. Visually inspect related harnesses, connectors and grounds; repair any physical damage. Ensure connectors are fully seated and pins straight.
  4. Verify power and ground at the suspect sensor/actuator connector with ignition on; compare to OEM reference voltages.
  5. Backprobe the signal wire while monitoring live data; verify signal behaves within expected range under varying engine conditions. Use oscilloscope for PWM or noisy signals.
  6. Check fuses and relays that supply the circuit; replace if suspect. Perform relay swap test if applicable.
  7. Perform continuity and resistance checks on wiring between sensor and ECM; repair any open/short. Wiggle harness while monitoring for intermittent faults.
  8. If wiring and power/grounds are good, substitute a known‑good sensor or actuator (if available) or bench‑test the component to confirm failure.
  9. If component replacement fixes the fault, clear codes and road test to verify. If issue persists and wiring/component good, consider ECM diagnosis or reflash by dealer/authorized shop.
  10. Document repairs and retest; if intermittent, leave vehicle for extended road test or install data logger to capture failing conditions.

Likely causes

  • Damaged wiring/connector (water ingress, chafing)
  • Failed sensor or actuator in the monitored circuit
  • Bad ground or supply voltage to sensor/actuator
  • Blown fuse or bad relay feeding the circuit
  • Intermittent connector contact or pin damage

Fault status

⚠️ Status
Manufacturer‑specific powertrain fault detected (P1238). ECM observed an abnormal signal; further diagnosis of circuit, sensor/actuator, wiring, power/ground or control module required.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 0.8-2.5 hours

Similar codes

P1237 P1239 P1240 P0190 P0230 P0300
136

Browse 136 PORSCHE manuals: repair procedures, diagnostics, wiring diagrams, component locations, service data and Labor Times by year, model and trim.

PORSCHE

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Code

P1238

SAAB P — Powertrain

Injector Circuit Cyl. 2 Open Or Short To Ground

Brand: SAAB
Type: P — Powertrain
AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • Open or shorted wiring in the monitored circuit
  • Corroded, loose or damaged connector or ground
  • Failed sensor or actuator associated with the monitored circuit
  • Faulty fuse, relay or power supply to the circuit
  • Intermittent fault caused by vibration or heat (broken wire or pin)
  • Faulty ECM or control module software/calibration

Symptoms

  • Malfunction indicator lamp (MIL) illuminated
  • Reduced engine performance or limp mode (if ECM limits functions)
  • Rough idle, hesitation or misfire-like symptoms
  • Hard starting or no-start in some cases
  • Degraded fuel economy or drivability issues
  • Intermittent faults that appear under specific conditions (temperature, load)

What to check

  • Read and record all stored codes and freeze frame data with a professional scan tool
  • Check for related manufacturer-specific codes that may point to subsystem
  • Inspect wiring harness and connectors at the suspected sensor/actuator for corrosion, damage or loose pins
  • Verify battery voltage and main grounds; low supply can cause false codes
  • Check fuses and relays that feed the suspect circuit
  • Perform wiggle test while monitoring relevant live data for intermittent changes

Signal parameters

  • Most sensor reference voltages: 5.0 V reference and ground present (measure at sensor connector)
  • Typical sensor signal range: 0–5.0 V (varies by sensor type)
  • CAN bus nominal idle voltage ~2.5 V (verify network communications if code references messages)
  • PWM actuators: duty cycle 0–100% and frequencies from tens to thousands of Hz (measure with scope)
  • Resistance checks: expected Ohms vary by component — consult OEM specs before replacing

Diagnostic algorithm

  1. Connect a capable OEM‑level or pro scan tool; read all DTCs and freeze frame. Note conditions when code set (RPM, load, temp, voltage).
  2. Check for technical service bulletins (TSBs) or software updates for P1238 on the specific Audi model/year.
  3. Visually inspect related harnesses, connectors and grounds; repair any physical damage. Ensure connectors are fully seated and pins straight.
  4. Verify power and ground at the suspect sensor/actuator connector with ignition on; compare to OEM reference voltages.
  5. Backprobe the signal wire while monitoring live data; verify signal behaves within expected range under varying engine conditions. Use oscilloscope for PWM or noisy signals.
  6. Check fuses and relays that supply the circuit; replace if suspect. Perform relay swap test if applicable.
  7. Perform continuity and resistance checks on wiring between sensor and ECM; repair any open/short. Wiggle harness while monitoring for intermittent faults.
  8. If wiring and power/grounds are good, substitute a known‑good sensor or actuator (if available) or bench‑test the component to confirm failure.
  9. If component replacement fixes the fault, clear codes and road test to verify. If issue persists and wiring/component good, consider ECM diagnosis or reflash by dealer/authorized shop.
  10. Document repairs and retest; if intermittent, leave vehicle for extended road test or install data logger to capture failing conditions.

Likely causes

  • Damaged wiring/connector (water ingress, chafing)
  • Failed sensor or actuator in the monitored circuit
  • Bad ground or supply voltage to sensor/actuator
  • Blown fuse or bad relay feeding the circuit
  • Intermittent connector contact or pin damage

Fault status

⚠️ Status
Manufacturer‑specific powertrain fault detected (P1238). ECM observed an abnormal signal; further diagnosis of circuit, sensor/actuator, wiring, power/ground or control module required.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 0.8-2.5 hours

Similar codes

P1237 P1239 P1240 P0190 P0230 P0300
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Code

P1238

VOLKSWAGEN P — Powertrain

Cylinder 2 Injector Circuit Open Circuit

Brand: VOLKSWAGEN
Type: P — Powertrain
AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • Open or shorted wiring in the monitored circuit
  • Corroded, loose or damaged connector or ground
  • Failed sensor or actuator associated with the monitored circuit
  • Faulty fuse, relay or power supply to the circuit
  • Intermittent fault caused by vibration or heat (broken wire or pin)
  • Faulty ECM or control module software/calibration

Symptoms

  • Malfunction indicator lamp (MIL) illuminated
  • Reduced engine performance or limp mode (if ECM limits functions)
  • Rough idle, hesitation or misfire-like symptoms
  • Hard starting or no-start in some cases
  • Degraded fuel economy or drivability issues
  • Intermittent faults that appear under specific conditions (temperature, load)

What to check

  • Read and record all stored codes and freeze frame data with a professional scan tool
  • Check for related manufacturer-specific codes that may point to subsystem
  • Inspect wiring harness and connectors at the suspected sensor/actuator for corrosion, damage or loose pins
  • Verify battery voltage and main grounds; low supply can cause false codes
  • Check fuses and relays that feed the suspect circuit
  • Perform wiggle test while monitoring relevant live data for intermittent changes

Signal parameters

  • Most sensor reference voltages: 5.0 V reference and ground present (measure at sensor connector)
  • Typical sensor signal range: 0–5.0 V (varies by sensor type)
  • CAN bus nominal idle voltage ~2.5 V (verify network communications if code references messages)
  • PWM actuators: duty cycle 0–100% and frequencies from tens to thousands of Hz (measure with scope)
  • Resistance checks: expected Ohms vary by component — consult OEM specs before replacing

Diagnostic algorithm

  1. Connect a capable OEM‑level or pro scan tool; read all DTCs and freeze frame. Note conditions when code set (RPM, load, temp, voltage).
  2. Check for technical service bulletins (TSBs) or software updates for P1238 on the specific Audi model/year.
  3. Visually inspect related harnesses, connectors and grounds; repair any physical damage. Ensure connectors are fully seated and pins straight.
  4. Verify power and ground at the suspect sensor/actuator connector with ignition on; compare to OEM reference voltages.
  5. Backprobe the signal wire while monitoring live data; verify signal behaves within expected range under varying engine conditions. Use oscilloscope for PWM or noisy signals.
  6. Check fuses and relays that supply the circuit; replace if suspect. Perform relay swap test if applicable.
  7. Perform continuity and resistance checks on wiring between sensor and ECM; repair any open/short. Wiggle harness while monitoring for intermittent faults.
  8. If wiring and power/grounds are good, substitute a known‑good sensor or actuator (if available) or bench‑test the component to confirm failure.
  9. If component replacement fixes the fault, clear codes and road test to verify. If issue persists and wiring/component good, consider ECM diagnosis or reflash by dealer/authorized shop.
  10. Document repairs and retest; if intermittent, leave vehicle for extended road test or install data logger to capture failing conditions.

Likely causes

  • Damaged wiring/connector (water ingress, chafing)
  • Failed sensor or actuator in the monitored circuit
  • Bad ground or supply voltage to sensor/actuator
  • Blown fuse or bad relay feeding the circuit
  • Intermittent connector contact or pin damage

Fault status

⚠️ Status
Manufacturer‑specific powertrain fault detected (P1238). ECM observed an abnormal signal; further diagnosis of circuit, sensor/actuator, wiring, power/ground or control module required.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 0.8-2.5 hours

Similar codes

P1237 P1239 P1240 P0190 P0230 P0300
626

Browse 626 VOLKSWAGEN manuals: repair procedures, diagnostics, wiring diagrams, component locations, service data and Labor Times by year, model and trim.

VOLKSWAGEN

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+100 karma for a short comment :)
Keep it short and practical. Up to 500 characters.
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