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Home / DTC / P0405 — EGR Sensor A Circuit Low

P0405 — EGR Sensor A Circuit Low

Detailed page for trouble code P0405.

34,405codes
59brands
11,914generic
22,491specific
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Code

P0405

Generic P — Powertrain

EGR Sensor A Circuit Low

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

Causes

  • Short to ground on the EGR sensor signal circuit
  • Open or damaged wiring/harness to the EGR sensor
  • Failed EGR position/pressure sensor (Sensor A)
  • Faulty sensor connector (corrosion, pulled pins, water intrusion)
  • Lost sensor reference voltage or ground
  • PCM/internal circuit fault (rare)

Symptoms

  • Check Engine MIL illuminated
  • Reduced engine performance or limp-home behavior (in some vehicles)
  • Rough idle, hesitation, or stalling under some conditions
  • Failed emissions test / increased NOx emissions
  • Stored or intermittent EGR-related trouble codes

What to check

  • Retrieve freeze frame and live data for EGR sensor voltage/position
  • Visual inspection of EGR sensor, connector, and wiring for damage or corrosion
  • Backprobe the EGR sensor connector and measure signal voltage with ignition on and engine running
  • Check for proper 5V reference (or vehicle-specific reference) and ground at the sensor
  • Wiggle test harness while monitoring signal for intermittent faults
  • Scan for related codes (P0400–P0408 family) and retest after clearing

Signal parameters

  • Typical system uses a 5 V reference, ground, and a signal return to PCM (vehicle dependent)
  • Low/fault condition generally = signal voltage near 0 V (commonly
  • Nominal signal range typically 0.5–4.5 V depending on sensor position and design
  • A valid reference voltage should be approximately 4.5–5.0 V with ignition on (verify vehicle spec)
  • Resistance between sensor ground and chassis ground should be very low (near 0 Ω)

Diagnostic algorithm

  1. Read and record freeze-frame and live data for EGR sensor voltage and related parameters. Note operating conditions when the code set.
  2. Clear the code, then drive or run engine to see if code returns and under what conditions.
  3. Perform a thorough visual inspection of the EGR sensor, connector, and wiring harness for damage, heat, or corrosion.
  4. Backprobe the sensor connector. With ignition on, measure reference voltage at sensor reference pin (should be ~5V or manufacturer spec).
  5. With engine running or commanded EGR conditions, measure the signal voltage. If signal is low (~0 V) while reference is present, suspect short to ground or failed sensor.
  6. Check continuity between the signal wire and chassis ground — if there is continuity, isolate and repair shorted section.
  7. Inspect and test the sensor ground circuit for high resistance. Repair poor ground connections as needed.
  8. If wiring and grounds check good, disconnect the sensor and measure its internal resistance or rotate the EGR mechanism (if applicable) to verify sensor changes. Replace sensor if it does not vary or reads out of spec.
  9. If harness and sensor test good, perform PCM input test or swap with known-good PCM if available (rare; confirm all other causes eliminated first).
  10. After repair, clear codes and verify the vehicle returns to normal operation and code does not return under the same conditions.

Likely causes

  • Signal wire chafed and contacting chassis ground
  • Corroded or bent pins at the sensor connector
  • Sensor failed internally and outputs near 0 V
  • Blown fuse or open power/reference feed to sensor
  • Poor engine/chassis ground affecting sensor circuit

Fault status

⚠️ Status
PCM detects EGR Sensor A circuit voltage below expected threshold (signal low). Possible short to ground, failed sensor, or loss of reference/ground.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 0.5-2.0 hours

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P0400 P0401 P0402 P0406 P0407 P0408
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Code

P0405

GWM P — Powertrain

- Low Sensor A of the Exhaust Gas Recirculation

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

Causes

  • Short to ground on the EGR sensor signal circuit
  • Open or damaged wiring/harness to the EGR sensor
  • Failed EGR position/pressure sensor (Sensor A)
  • Faulty sensor connector (corrosion, pulled pins, water intrusion)
  • Lost sensor reference voltage or ground
  • PCM/internal circuit fault (rare)

Symptoms

  • Check Engine MIL illuminated
  • Reduced engine performance or limp-home behavior (in some vehicles)
  • Rough idle, hesitation, or stalling under some conditions
  • Failed emissions test / increased NOx emissions
  • Stored or intermittent EGR-related trouble codes

What to check

  • Retrieve freeze frame and live data for EGR sensor voltage/position
  • Visual inspection of EGR sensor, connector, and wiring for damage or corrosion
  • Backprobe the EGR sensor connector and measure signal voltage with ignition on and engine running
  • Check for proper 5V reference (or vehicle-specific reference) and ground at the sensor
  • Wiggle test harness while monitoring signal for intermittent faults
  • Scan for related codes (P0400–P0408 family) and retest after clearing

Signal parameters

  • Typical system uses a 5 V reference, ground, and a signal return to PCM (vehicle dependent)
  • Low/fault condition generally = signal voltage near 0 V (commonly
  • Nominal signal range typically 0.5–4.5 V depending on sensor position and design
  • A valid reference voltage should be approximately 4.5–5.0 V with ignition on (verify vehicle spec)
  • Resistance between sensor ground and chassis ground should be very low (near 0 Ω)

Diagnostic algorithm

  1. Read and record freeze-frame and live data for EGR sensor voltage and related parameters. Note operating conditions when the code set.
  2. Clear the code, then drive or run engine to see if code returns and under what conditions.
  3. Perform a thorough visual inspection of the EGR sensor, connector, and wiring harness for damage, heat, or corrosion.
  4. Backprobe the sensor connector. With ignition on, measure reference voltage at sensor reference pin (should be ~5V or manufacturer spec).
  5. With engine running or commanded EGR conditions, measure the signal voltage. If signal is low (~0 V) while reference is present, suspect short to ground or failed sensor.
  6. Check continuity between the signal wire and chassis ground — if there is continuity, isolate and repair shorted section.
  7. Inspect and test the sensor ground circuit for high resistance. Repair poor ground connections as needed.
  8. If wiring and grounds check good, disconnect the sensor and measure its internal resistance or rotate the EGR mechanism (if applicable) to verify sensor changes. Replace sensor if it does not vary or reads out of spec.
  9. If harness and sensor test good, perform PCM input test or swap with known-good PCM if available (rare; confirm all other causes eliminated first).
  10. After repair, clear codes and verify the vehicle returns to normal operation and code does not return under the same conditions.

Likely causes

  • Signal wire chafed and contacting chassis ground
  • Corroded or bent pins at the sensor connector
  • Sensor failed internally and outputs near 0 V
  • Blown fuse or open power/reference feed to sensor
  • Poor engine/chassis ground affecting sensor circuit

Fault status

⚠️ Status
PCM detects EGR Sensor A circuit voltage below expected threshold (signal low). Possible short to ground, failed sensor, or loss of reference/ground.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 0.5-2.0 hours

Similar codes

P0400 P0401 P0402 P0406 P0407 P0408
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Code

P0405

HUMMER P — Powertrain

Exhaust Gas Recirculation (EGR) Position Sensor Circuit Low Voltage

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

Causes

  • Short to ground on the EGR sensor signal circuit
  • Open or damaged wiring/harness to the EGR sensor
  • Failed EGR position/pressure sensor (Sensor A)
  • Faulty sensor connector (corrosion, pulled pins, water intrusion)
  • Lost sensor reference voltage or ground
  • PCM/internal circuit fault (rare)

Symptoms

  • Check Engine MIL illuminated
  • Reduced engine performance or limp-home behavior (in some vehicles)
  • Rough idle, hesitation, or stalling under some conditions
  • Failed emissions test / increased NOx emissions
  • Stored or intermittent EGR-related trouble codes

What to check

  • Retrieve freeze frame and live data for EGR sensor voltage/position
  • Visual inspection of EGR sensor, connector, and wiring for damage or corrosion
  • Backprobe the EGR sensor connector and measure signal voltage with ignition on and engine running
  • Check for proper 5V reference (or vehicle-specific reference) and ground at the sensor
  • Wiggle test harness while monitoring signal for intermittent faults
  • Scan for related codes (P0400–P0408 family) and retest after clearing

Signal parameters

  • Typical system uses a 5 V reference, ground, and a signal return to PCM (vehicle dependent)
  • Low/fault condition generally = signal voltage near 0 V (commonly
  • Nominal signal range typically 0.5–4.5 V depending on sensor position and design
  • A valid reference voltage should be approximately 4.5–5.0 V with ignition on (verify vehicle spec)
  • Resistance between sensor ground and chassis ground should be very low (near 0 Ω)

Diagnostic algorithm

  1. Read and record freeze-frame and live data for EGR sensor voltage and related parameters. Note operating conditions when the code set.
  2. Clear the code, then drive or run engine to see if code returns and under what conditions.
  3. Perform a thorough visual inspection of the EGR sensor, connector, and wiring harness for damage, heat, or corrosion.
  4. Backprobe the sensor connector. With ignition on, measure reference voltage at sensor reference pin (should be ~5V or manufacturer spec).
  5. With engine running or commanded EGR conditions, measure the signal voltage. If signal is low (~0 V) while reference is present, suspect short to ground or failed sensor.
  6. Check continuity between the signal wire and chassis ground — if there is continuity, isolate and repair shorted section.
  7. Inspect and test the sensor ground circuit for high resistance. Repair poor ground connections as needed.
  8. If wiring and grounds check good, disconnect the sensor and measure its internal resistance or rotate the EGR mechanism (if applicable) to verify sensor changes. Replace sensor if it does not vary or reads out of spec.
  9. If harness and sensor test good, perform PCM input test or swap with known-good PCM if available (rare; confirm all other causes eliminated first).
  10. After repair, clear codes and verify the vehicle returns to normal operation and code does not return under the same conditions.

Likely causes

  • Signal wire chafed and contacting chassis ground
  • Corroded or bent pins at the sensor connector
  • Sensor failed internally and outputs near 0 V
  • Blown fuse or open power/reference feed to sensor
  • Poor engine/chassis ground affecting sensor circuit

Fault status

⚠️ Status
PCM detects EGR Sensor A circuit voltage below expected threshold (signal low). Possible short to ground, failed sensor, or loss of reference/ground.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 0.5-2.0 hours

Similar codes

P0400 P0401 P0402 P0406 P0407 P0408
Repair manuals

Manual library for HUMMER

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Code

P0405

LAND ROVER P — Powertrain

Exhaust Gas Recirculation Sensor Low Input Circuit

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

Causes

  • Short to ground on the EGR sensor signal circuit
  • Open or damaged wiring/harness to the EGR sensor
  • Failed EGR position/pressure sensor (Sensor A)
  • Faulty sensor connector (corrosion, pulled pins, water intrusion)
  • Lost sensor reference voltage or ground
  • PCM/internal circuit fault (rare)

Symptoms

  • Check Engine MIL illuminated
  • Reduced engine performance or limp-home behavior (in some vehicles)
  • Rough idle, hesitation, or stalling under some conditions
  • Failed emissions test / increased NOx emissions
  • Stored or intermittent EGR-related trouble codes

What to check

  • Retrieve freeze frame and live data for EGR sensor voltage/position
  • Visual inspection of EGR sensor, connector, and wiring for damage or corrosion
  • Backprobe the EGR sensor connector and measure signal voltage with ignition on and engine running
  • Check for proper 5V reference (or vehicle-specific reference) and ground at the sensor
  • Wiggle test harness while monitoring signal for intermittent faults
  • Scan for related codes (P0400–P0408 family) and retest after clearing

Signal parameters

  • Typical system uses a 5 V reference, ground, and a signal return to PCM (vehicle dependent)
  • Low/fault condition generally = signal voltage near 0 V (commonly
  • Nominal signal range typically 0.5–4.5 V depending on sensor position and design
  • A valid reference voltage should be approximately 4.5–5.0 V with ignition on (verify vehicle spec)
  • Resistance between sensor ground and chassis ground should be very low (near 0 Ω)

Diagnostic algorithm

  1. Read and record freeze-frame and live data for EGR sensor voltage and related parameters. Note operating conditions when the code set.
  2. Clear the code, then drive or run engine to see if code returns and under what conditions.
  3. Perform a thorough visual inspection of the EGR sensor, connector, and wiring harness for damage, heat, or corrosion.
  4. Backprobe the sensor connector. With ignition on, measure reference voltage at sensor reference pin (should be ~5V or manufacturer spec).
  5. With engine running or commanded EGR conditions, measure the signal voltage. If signal is low (~0 V) while reference is present, suspect short to ground or failed sensor.
  6. Check continuity between the signal wire and chassis ground — if there is continuity, isolate and repair shorted section.
  7. Inspect and test the sensor ground circuit for high resistance. Repair poor ground connections as needed.
  8. If wiring and grounds check good, disconnect the sensor and measure its internal resistance or rotate the EGR mechanism (if applicable) to verify sensor changes. Replace sensor if it does not vary or reads out of spec.
  9. If harness and sensor test good, perform PCM input test or swap with known-good PCM if available (rare; confirm all other causes eliminated first).
  10. After repair, clear codes and verify the vehicle returns to normal operation and code does not return under the same conditions.

Likely causes

  • Signal wire chafed and contacting chassis ground
  • Corroded or bent pins at the sensor connector
  • Sensor failed internally and outputs near 0 V
  • Blown fuse or open power/reference feed to sensor
  • Poor engine/chassis ground affecting sensor circuit

Fault status

⚠️ Status
PCM detects EGR Sensor A circuit voltage below expected threshold (signal low). Possible short to ground, failed sensor, or loss of reference/ground.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 0.5-2.0 hours

Similar codes

P0400 P0401 P0402 P0406 P0407 P0408
320

Browse 320 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

P0405

MITSUBISHI P — Powertrain

EGR lift sensor circuit low

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

Causes

  • Short to ground on the EGR sensor signal circuit
  • Open or damaged wiring/harness to the EGR sensor
  • Failed EGR position/pressure sensor (Sensor A)
  • Faulty sensor connector (corrosion, pulled pins, water intrusion)
  • Lost sensor reference voltage or ground
  • PCM/internal circuit fault (rare)

Symptoms

  • Check Engine MIL illuminated
  • Reduced engine performance or limp-home behavior (in some vehicles)
  • Rough idle, hesitation, or stalling under some conditions
  • Failed emissions test / increased NOx emissions
  • Stored or intermittent EGR-related trouble codes

What to check

  • Retrieve freeze frame and live data for EGR sensor voltage/position
  • Visual inspection of EGR sensor, connector, and wiring for damage or corrosion
  • Backprobe the EGR sensor connector and measure signal voltage with ignition on and engine running
  • Check for proper 5V reference (or vehicle-specific reference) and ground at the sensor
  • Wiggle test harness while monitoring signal for intermittent faults
  • Scan for related codes (P0400–P0408 family) and retest after clearing

Signal parameters

  • Typical system uses a 5 V reference, ground, and a signal return to PCM (vehicle dependent)
  • Low/fault condition generally = signal voltage near 0 V (commonly
  • Nominal signal range typically 0.5–4.5 V depending on sensor position and design
  • A valid reference voltage should be approximately 4.5–5.0 V with ignition on (verify vehicle spec)
  • Resistance between sensor ground and chassis ground should be very low (near 0 Ω)

Diagnostic algorithm

  1. Read and record freeze-frame and live data for EGR sensor voltage and related parameters. Note operating conditions when the code set.
  2. Clear the code, then drive or run engine to see if code returns and under what conditions.
  3. Perform a thorough visual inspection of the EGR sensor, connector, and wiring harness for damage, heat, or corrosion.
  4. Backprobe the sensor connector. With ignition on, measure reference voltage at sensor reference pin (should be ~5V or manufacturer spec).
  5. With engine running or commanded EGR conditions, measure the signal voltage. If signal is low (~0 V) while reference is present, suspect short to ground or failed sensor.
  6. Check continuity between the signal wire and chassis ground — if there is continuity, isolate and repair shorted section.
  7. Inspect and test the sensor ground circuit for high resistance. Repair poor ground connections as needed.
  8. If wiring and grounds check good, disconnect the sensor and measure its internal resistance or rotate the EGR mechanism (if applicable) to verify sensor changes. Replace sensor if it does not vary or reads out of spec.
  9. If harness and sensor test good, perform PCM input test or swap with known-good PCM if available (rare; confirm all other causes eliminated first).
  10. After repair, clear codes and verify the vehicle returns to normal operation and code does not return under the same conditions.

Likely causes

  • Signal wire chafed and contacting chassis ground
  • Corroded or bent pins at the sensor connector
  • Sensor failed internally and outputs near 0 V
  • Blown fuse or open power/reference feed to sensor
  • Poor engine/chassis ground affecting sensor circuit

Fault status

⚠️ Status
PCM detects EGR Sensor A circuit voltage below expected threshold (signal low). Possible short to ground, failed sensor, or loss of reference/ground.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 0.5-2.0 hours

Similar codes

P0400 P0401 P0402 P0406 P0407 P0408
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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