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Home / DTC / P0038 — HO2S Heater Control Circuit High Bank 1 Sensor 2

P0038 — HO2S Heater Control Circuit High Bank 1 Sensor 2

Detailed page for trouble code P0038.

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Code

P0038

Generic P — Powertrain

HO2S Heater Control Circuit High Bank 1 Sensor 2

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

Causes

  • Open or high-resistance heater circuit (broken wire, corroded connector)
  • Short to battery voltage on heater control/return circuit
  • Blown fuse or fusible link supplying the heater
  • Failed oxygen sensor (heater element open or internally shorted)
  • Poor or corroded connector/pins at the sensor or harness
  • PCM/ECM heater driver fault (rare)

Symptoms

  • Malfunction Indicator Lamp (MIL) illuminated
  • Possible failed emissions test or stored emissions-related readiness code
  • Check-engine light may stay on after startup
  • Usually no major drivability issues, but fuel trims or catalyst monitoring may be affected
  • Reduced heater operation can increase catalyst light-off time and emissions

What to check

  • Read freeze frame and freeze-frame data, confirm P0038 is current/confirmed
  • Visually inspect sensor wiring, connector, and harness for damage, corrosion or disconnection
  • Check related fuses and relays for the O2 sensor heater circuit
  • Backprobe heater power and control wires at the sensor connector while performing heater command
  • Measure heater element resistance at the sensor (unplugged)
  • Check for voltage short to battery and for continuity to PCM ground on the control circuit

Signal parameters

  • Heater element resistance (sensor unplugged): typically low (commonly ~2–50 ohms depending on sensor) — should not be open (>infinite)
  • Supply side (battery/fused): battery voltage present (approx. 11–14 V) with key ON
  • Control/driver side when PCM commands heater ON: expected near ground (low voltage, typically
  • If circuit is 'high' the measured voltage on the control circuit may be higher than the PCM expects (indicating open or short to voltage)

Diagnostic algorithm

  1. Verify the code with a scan tool. Note freeze frame data and readiness status. Clear code and attempt to re-run to confirm.
  2. Perform a visual inspection of the Bank 1 Sensor 2 connector, wiring, and nearby harness for heat damage, corrosion, or chafing.
  3. Check fuses/relays related to O2 sensor heaters. Replace any blown fuse and retest.
  4. With ignition OFF, disconnect the sensor. Measure heater element resistance across the heater pins. If open/infinite, replace the sensor.
  5. With backprobe and key ON, verify battery voltage at the heater supply pin. If no supply, trace supply circuit to fuse/relay/battery.
  6. Command the heater ON with a bi-directional scan tool (if available). Measure voltage on the control/driver pin. If PCM grounds the circuit, the driver pin should go low when commanded ON. If it remains high, check for short to battery or open in the ground path.
  7. Check continuity from the sensor control pin to the PCM; check for shorts to battery on that wire. Repair any wiring faults or connectors found.
  8. If wiring and sensor test good, test or replace the PCM only after confirming driver fault with proper test equipment or manufacturer procedures.
  9. After repairs, clear codes and perform a drive cycle to verify code does not return and that readiness tests complete.

Likely causes

  • Disconnected or damaged sensor connector at Bank 1 Sensor 2
  • Open heater element inside the downstream O2 sensor
  • Wiring shorted to battery voltage (power side) or open on control/ground side
  • Blown heater fuse for oxygen sensors
  • Corroded ground or wiring harness chafed at heat/sharp edge

Fault status

⚠️ Status
HO2S Heater Control Circuit High - Bank 1 Sensor 2
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 0.8-2.5 hours

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Code

P0038

HUMMER P — Powertrain

Heated Oxygen Sensor (HO2S) Heater Circuit High Voltage Bank 1 Sensor 2

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

Causes

  • Open or high-resistance heater circuit (broken wire, corroded connector)
  • Short to battery voltage on heater control/return circuit
  • Blown fuse or fusible link supplying the heater
  • Failed oxygen sensor (heater element open or internally shorted)
  • Poor or corroded connector/pins at the sensor or harness
  • PCM/ECM heater driver fault (rare)

Symptoms

  • Malfunction Indicator Lamp (MIL) illuminated
  • Possible failed emissions test or stored emissions-related readiness code
  • Check-engine light may stay on after startup
  • Usually no major drivability issues, but fuel trims or catalyst monitoring may be affected
  • Reduced heater operation can increase catalyst light-off time and emissions

What to check

  • Read freeze frame and freeze-frame data, confirm P0038 is current/confirmed
  • Visually inspect sensor wiring, connector, and harness for damage, corrosion or disconnection
  • Check related fuses and relays for the O2 sensor heater circuit
  • Backprobe heater power and control wires at the sensor connector while performing heater command
  • Measure heater element resistance at the sensor (unplugged)
  • Check for voltage short to battery and for continuity to PCM ground on the control circuit

Signal parameters

  • Heater element resistance (sensor unplugged): typically low (commonly ~2–50 ohms depending on sensor) — should not be open (>infinite)
  • Supply side (battery/fused): battery voltage present (approx. 11–14 V) with key ON
  • Control/driver side when PCM commands heater ON: expected near ground (low voltage, typically
  • If circuit is 'high' the measured voltage on the control circuit may be higher than the PCM expects (indicating open or short to voltage)

Diagnostic algorithm

  1. Verify the code with a scan tool. Note freeze frame data and readiness status. Clear code and attempt to re-run to confirm.
  2. Perform a visual inspection of the Bank 1 Sensor 2 connector, wiring, and nearby harness for heat damage, corrosion, or chafing.
  3. Check fuses/relays related to O2 sensor heaters. Replace any blown fuse and retest.
  4. With ignition OFF, disconnect the sensor. Measure heater element resistance across the heater pins. If open/infinite, replace the sensor.
  5. With backprobe and key ON, verify battery voltage at the heater supply pin. If no supply, trace supply circuit to fuse/relay/battery.
  6. Command the heater ON with a bi-directional scan tool (if available). Measure voltage on the control/driver pin. If PCM grounds the circuit, the driver pin should go low when commanded ON. If it remains high, check for short to battery or open in the ground path.
  7. Check continuity from the sensor control pin to the PCM; check for shorts to battery on that wire. Repair any wiring faults or connectors found.
  8. If wiring and sensor test good, test or replace the PCM only after confirming driver fault with proper test equipment or manufacturer procedures.
  9. After repairs, clear codes and perform a drive cycle to verify code does not return and that readiness tests complete.

Likely causes

  • Disconnected or damaged sensor connector at Bank 1 Sensor 2
  • Open heater element inside the downstream O2 sensor
  • Wiring shorted to battery voltage (power side) or open on control/ground side
  • Blown heater fuse for oxygen sensors
  • Corroded ground or wiring harness chafed at heat/sharp edge

Fault status

⚠️ Status
HO2S Heater Control Circuit High - Bank 1 Sensor 2
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 0.8-2.5 hours

Similar codes

P0037 P0058 P0135 P0138 P0141
Repair manuals

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Code

P0038

HYUNDAI P — Powertrain

O2 Sensor Heater Control Circuit High (Bank 1, Sensor 2)

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

Causes

  • Open or high-resistance heater circuit (broken wire, corroded connector)
  • Short to battery voltage on heater control/return circuit
  • Blown fuse or fusible link supplying the heater
  • Failed oxygen sensor (heater element open or internally shorted)
  • Poor or corroded connector/pins at the sensor or harness
  • PCM/ECM heater driver fault (rare)

Symptoms

  • Malfunction Indicator Lamp (MIL) illuminated
  • Possible failed emissions test or stored emissions-related readiness code
  • Check-engine light may stay on after startup
  • Usually no major drivability issues, but fuel trims or catalyst monitoring may be affected
  • Reduced heater operation can increase catalyst light-off time and emissions

What to check

  • Read freeze frame and freeze-frame data, confirm P0038 is current/confirmed
  • Visually inspect sensor wiring, connector, and harness for damage, corrosion or disconnection
  • Check related fuses and relays for the O2 sensor heater circuit
  • Backprobe heater power and control wires at the sensor connector while performing heater command
  • Measure heater element resistance at the sensor (unplugged)
  • Check for voltage short to battery and for continuity to PCM ground on the control circuit

Signal parameters

  • Heater element resistance (sensor unplugged): typically low (commonly ~2–50 ohms depending on sensor) — should not be open (>infinite)
  • Supply side (battery/fused): battery voltage present (approx. 11–14 V) with key ON
  • Control/driver side when PCM commands heater ON: expected near ground (low voltage, typically
  • If circuit is 'high' the measured voltage on the control circuit may be higher than the PCM expects (indicating open or short to voltage)

Diagnostic algorithm

  1. Verify the code with a scan tool. Note freeze frame data and readiness status. Clear code and attempt to re-run to confirm.
  2. Perform a visual inspection of the Bank 1 Sensor 2 connector, wiring, and nearby harness for heat damage, corrosion, or chafing.
  3. Check fuses/relays related to O2 sensor heaters. Replace any blown fuse and retest.
  4. With ignition OFF, disconnect the sensor. Measure heater element resistance across the heater pins. If open/infinite, replace the sensor.
  5. With backprobe and key ON, verify battery voltage at the heater supply pin. If no supply, trace supply circuit to fuse/relay/battery.
  6. Command the heater ON with a bi-directional scan tool (if available). Measure voltage on the control/driver pin. If PCM grounds the circuit, the driver pin should go low when commanded ON. If it remains high, check for short to battery or open in the ground path.
  7. Check continuity from the sensor control pin to the PCM; check for shorts to battery on that wire. Repair any wiring faults or connectors found.
  8. If wiring and sensor test good, test or replace the PCM only after confirming driver fault with proper test equipment or manufacturer procedures.
  9. After repairs, clear codes and perform a drive cycle to verify code does not return and that readiness tests complete.

Likely causes

  • Disconnected or damaged sensor connector at Bank 1 Sensor 2
  • Open heater element inside the downstream O2 sensor
  • Wiring shorted to battery voltage (power side) or open on control/ground side
  • Blown heater fuse for oxygen sensors
  • Corroded ground or wiring harness chafed at heat/sharp edge

Fault status

⚠️ Status
HO2S Heater Control Circuit High - Bank 1 Sensor 2
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 0.8-2.5 hours

Similar codes

P0037 P0058 P0135 P0138 P0141
371

Browse 371 HYUNDAI manuals: repair procedures, diagnostics, wiring diagrams, component locations, service data and Labor Times by year, model and trim.

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Code

P0038

LAND ROVER P — Powertrain

High Heated Oxygen Sensor Heater Control Circuit (bank 1 sensor 2)

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

Causes

  • Open or high-resistance heater circuit (broken wire, corroded connector)
  • Short to battery voltage on heater control/return circuit
  • Blown fuse or fusible link supplying the heater
  • Failed oxygen sensor (heater element open or internally shorted)
  • Poor or corroded connector/pins at the sensor or harness
  • PCM/ECM heater driver fault (rare)

Symptoms

  • Malfunction Indicator Lamp (MIL) illuminated
  • Possible failed emissions test or stored emissions-related readiness code
  • Check-engine light may stay on after startup
  • Usually no major drivability issues, but fuel trims or catalyst monitoring may be affected
  • Reduced heater operation can increase catalyst light-off time and emissions

What to check

  • Read freeze frame and freeze-frame data, confirm P0038 is current/confirmed
  • Visually inspect sensor wiring, connector, and harness for damage, corrosion or disconnection
  • Check related fuses and relays for the O2 sensor heater circuit
  • Backprobe heater power and control wires at the sensor connector while performing heater command
  • Measure heater element resistance at the sensor (unplugged)
  • Check for voltage short to battery and for continuity to PCM ground on the control circuit

Signal parameters

  • Heater element resistance (sensor unplugged): typically low (commonly ~2–50 ohms depending on sensor) — should not be open (>infinite)
  • Supply side (battery/fused): battery voltage present (approx. 11–14 V) with key ON
  • Control/driver side when PCM commands heater ON: expected near ground (low voltage, typically
  • If circuit is 'high' the measured voltage on the control circuit may be higher than the PCM expects (indicating open or short to voltage)

Diagnostic algorithm

  1. Verify the code with a scan tool. Note freeze frame data and readiness status. Clear code and attempt to re-run to confirm.
  2. Perform a visual inspection of the Bank 1 Sensor 2 connector, wiring, and nearby harness for heat damage, corrosion, or chafing.
  3. Check fuses/relays related to O2 sensor heaters. Replace any blown fuse and retest.
  4. With ignition OFF, disconnect the sensor. Measure heater element resistance across the heater pins. If open/infinite, replace the sensor.
  5. With backprobe and key ON, verify battery voltage at the heater supply pin. If no supply, trace supply circuit to fuse/relay/battery.
  6. Command the heater ON with a bi-directional scan tool (if available). Measure voltage on the control/driver pin. If PCM grounds the circuit, the driver pin should go low when commanded ON. If it remains high, check for short to battery or open in the ground path.
  7. Check continuity from the sensor control pin to the PCM; check for shorts to battery on that wire. Repair any wiring faults or connectors found.
  8. If wiring and sensor test good, test or replace the PCM only after confirming driver fault with proper test equipment or manufacturer procedures.
  9. After repairs, clear codes and perform a drive cycle to verify code does not return and that readiness tests complete.

Likely causes

  • Disconnected or damaged sensor connector at Bank 1 Sensor 2
  • Open heater element inside the downstream O2 sensor
  • Wiring shorted to battery voltage (power side) or open on control/ground side
  • Blown heater fuse for oxygen sensors
  • Corroded ground or wiring harness chafed at heat/sharp edge

Fault status

⚠️ Status
HO2S Heater Control Circuit High - Bank 1 Sensor 2
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 0.8-2.5 hours

Similar codes

P0037 P0058 P0135 P0138 P0141
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

P0038

MITSUBISHI P — Powertrain

Oxygen sensor heater(rear) high

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

Causes

  • Open or high-resistance heater circuit (broken wire, corroded connector)
  • Short to battery voltage on heater control/return circuit
  • Blown fuse or fusible link supplying the heater
  • Failed oxygen sensor (heater element open or internally shorted)
  • Poor or corroded connector/pins at the sensor or harness
  • PCM/ECM heater driver fault (rare)

Symptoms

  • Malfunction Indicator Lamp (MIL) illuminated
  • Possible failed emissions test or stored emissions-related readiness code
  • Check-engine light may stay on after startup
  • Usually no major drivability issues, but fuel trims or catalyst monitoring may be affected
  • Reduced heater operation can increase catalyst light-off time and emissions

What to check

  • Read freeze frame and freeze-frame data, confirm P0038 is current/confirmed
  • Visually inspect sensor wiring, connector, and harness for damage, corrosion or disconnection
  • Check related fuses and relays for the O2 sensor heater circuit
  • Backprobe heater power and control wires at the sensor connector while performing heater command
  • Measure heater element resistance at the sensor (unplugged)
  • Check for voltage short to battery and for continuity to PCM ground on the control circuit

Signal parameters

  • Heater element resistance (sensor unplugged): typically low (commonly ~2–50 ohms depending on sensor) — should not be open (>infinite)
  • Supply side (battery/fused): battery voltage present (approx. 11–14 V) with key ON
  • Control/driver side when PCM commands heater ON: expected near ground (low voltage, typically
  • If circuit is 'high' the measured voltage on the control circuit may be higher than the PCM expects (indicating open or short to voltage)

Diagnostic algorithm

  1. Verify the code with a scan tool. Note freeze frame data and readiness status. Clear code and attempt to re-run to confirm.
  2. Perform a visual inspection of the Bank 1 Sensor 2 connector, wiring, and nearby harness for heat damage, corrosion, or chafing.
  3. Check fuses/relays related to O2 sensor heaters. Replace any blown fuse and retest.
  4. With ignition OFF, disconnect the sensor. Measure heater element resistance across the heater pins. If open/infinite, replace the sensor.
  5. With backprobe and key ON, verify battery voltage at the heater supply pin. If no supply, trace supply circuit to fuse/relay/battery.
  6. Command the heater ON with a bi-directional scan tool (if available). Measure voltage on the control/driver pin. If PCM grounds the circuit, the driver pin should go low when commanded ON. If it remains high, check for short to battery or open in the ground path.
  7. Check continuity from the sensor control pin to the PCM; check for shorts to battery on that wire. Repair any wiring faults or connectors found.
  8. If wiring and sensor test good, test or replace the PCM only after confirming driver fault with proper test equipment or manufacturer procedures.
  9. After repairs, clear codes and perform a drive cycle to verify code does not return and that readiness tests complete.

Likely causes

  • Disconnected or damaged sensor connector at Bank 1 Sensor 2
  • Open heater element inside the downstream O2 sensor
  • Wiring shorted to battery voltage (power side) or open on control/ground side
  • Blown heater fuse for oxygen sensors
  • Corroded ground or wiring harness chafed at heat/sharp edge

Fault status

⚠️ Status
HO2S Heater Control Circuit High - Bank 1 Sensor 2
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 0.8-2.5 hours

Similar codes

P0037 P0058 P0135 P0138 P0141
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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+100 karma for a short comment :)
Keep it short and practical. Up to 500 characters.
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Code

P0038

VOLKSWAGEN P — Powertrain

O2 Sensor Heater Control Circuit High (Bank 1, Sensor 2)

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

Causes

  • Open or high-resistance heater circuit (broken wire, corroded connector)
  • Short to battery voltage on heater control/return circuit
  • Blown fuse or fusible link supplying the heater
  • Failed oxygen sensor (heater element open or internally shorted)
  • Poor or corroded connector/pins at the sensor or harness
  • PCM/ECM heater driver fault (rare)

Symptoms

  • Malfunction Indicator Lamp (MIL) illuminated
  • Possible failed emissions test or stored emissions-related readiness code
  • Check-engine light may stay on after startup
  • Usually no major drivability issues, but fuel trims or catalyst monitoring may be affected
  • Reduced heater operation can increase catalyst light-off time and emissions

What to check

  • Read freeze frame and freeze-frame data, confirm P0038 is current/confirmed
  • Visually inspect sensor wiring, connector, and harness for damage, corrosion or disconnection
  • Check related fuses and relays for the O2 sensor heater circuit
  • Backprobe heater power and control wires at the sensor connector while performing heater command
  • Measure heater element resistance at the sensor (unplugged)
  • Check for voltage short to battery and for continuity to PCM ground on the control circuit

Signal parameters

  • Heater element resistance (sensor unplugged): typically low (commonly ~2–50 ohms depending on sensor) — should not be open (>infinite)
  • Supply side (battery/fused): battery voltage present (approx. 11–14 V) with key ON
  • Control/driver side when PCM commands heater ON: expected near ground (low voltage, typically
  • If circuit is 'high' the measured voltage on the control circuit may be higher than the PCM expects (indicating open or short to voltage)

Diagnostic algorithm

  1. Verify the code with a scan tool. Note freeze frame data and readiness status. Clear code and attempt to re-run to confirm.
  2. Perform a visual inspection of the Bank 1 Sensor 2 connector, wiring, and nearby harness for heat damage, corrosion, or chafing.
  3. Check fuses/relays related to O2 sensor heaters. Replace any blown fuse and retest.
  4. With ignition OFF, disconnect the sensor. Measure heater element resistance across the heater pins. If open/infinite, replace the sensor.
  5. With backprobe and key ON, verify battery voltage at the heater supply pin. If no supply, trace supply circuit to fuse/relay/battery.
  6. Command the heater ON with a bi-directional scan tool (if available). Measure voltage on the control/driver pin. If PCM grounds the circuit, the driver pin should go low when commanded ON. If it remains high, check for short to battery or open in the ground path.
  7. Check continuity from the sensor control pin to the PCM; check for shorts to battery on that wire. Repair any wiring faults or connectors found.
  8. If wiring and sensor test good, test or replace the PCM only after confirming driver fault with proper test equipment or manufacturer procedures.
  9. After repairs, clear codes and perform a drive cycle to verify code does not return and that readiness tests complete.

Likely causes

  • Disconnected or damaged sensor connector at Bank 1 Sensor 2
  • Open heater element inside the downstream O2 sensor
  • Wiring shorted to battery voltage (power side) or open on control/ground side
  • Blown heater fuse for oxygen sensors
  • Corroded ground or wiring harness chafed at heat/sharp edge

Fault status

⚠️ Status
HO2S Heater Control Circuit High - Bank 1 Sensor 2
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 0.8-2.5 hours

Similar codes

P0037 P0058 P0135 P0138 P0141
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.
Send to email

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