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Home / DTC / P0403 — EGR A Control Circuit/Open

P0403 — EGR A Control Circuit/Open

Detailed page for trouble code P0403.

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

P0403

Generic P — Powertrain

EGR A Control Circuit/Open

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

Causes

  • Open or shorted wiring in EGR control circuit
  • Corroded, loose or damaged EGR connector
  • Failed EGR solenoid/actuator
  • Blown fuse or bad relay feeding the EGR circuit
  • Faulty PCM (less common)
  • Poor chassis or engine ground

Symptoms

  • Malfunction Indicator Lamp (MIL) illuminated
  • Rough idle or hesitation
  • Reduced engine performance or drivability issues
  • Higher NOx emissions / failed emissions test
  • Possible stalling at idle
  • Check engine light with related EGR faults

What to check

  • Read stored freeze frame and freeze data with a scan tool
  • Visual inspection of EGR valve, solenoid, wiring and connectors for damage or corrosion
  • Check relevant fuses and relays
  • Backprobe EGR connector while commanding with scan tool to observe signal
  • Measure continuity between PCM pin and EGR connector pin
  • Measure coil resistance of EGR solenoid (compare to spec or typical range)

Signal parameters

  • Key ON, engine OFF: 12 V supply should be present at the EGR solenoid power terminal (if applicable)
  • Control side: PCM may switch ground or battery feed depending on design — expected to show change when commanded
  • When commanded by scan tool: voltage or duty-cycle at control line should change from resting value to commanded value (0–100% duty or solid on/off)
  • Typical EGR solenoid coil resistance (varies by manufacturer): commonly ~10–50 Ω — check vehicle-specific spec
  • Open-circuit indication: infinite resistance (OL) between EGR actuator terminals or between actuator and PCM

Diagnostic algorithm

  1. Retrieve codes and freeze frame data. Note engine conditions when DTC set.
  2. Perform a visual inspection of the EGR valve/solenoid, harness, and connectors for damage, corrosion or heat damage.
  3. Check fuses/relays that supply the EGR circuits; replace if blown.
  4. With ignition ON (engine OFF), backprobe the EGR connector. Verify 12 V supply (if applicable) and good ground reference. Compare to wiring diagram for circuit polarity.
  5. Command the EGR valve ON/OFF with a scan tool while monitoring the control circuit voltage/duty. If PCM commands but no change at connector, suspect wiring between PCM and actuator.
  6. Remove connector and measure EGR actuator coil resistance. Open/infinite resistance = bad actuator.
  7. Check continuity between the PCM pin and the EGR connector pin. Repair any open or high-resistance sections.
  8. If wiring and actuator verify OK, check for intermittent faults by wiggle-testing harness under load/while commanded.
  9. Repair or replace faulty wiring, connector, fuse, relay or EGR actuator as required. After repair, clear codes and perform functional/road test to verify.
  10. If fault persists after harness and actuator replacement, consult manufacturer wiring diagrams and consider PCM/ground integrity testing or replacement.

Likely causes

  • Disconnected or broken harness between PCM and EGR valve
  • Pin pushed out or corrosion at connector causing open
  • EGR solenoid coil failed open
  • Fuse for emission solenoids blown
  • Connector damaged by heat/road debris

Fault status

⚠️ Status
EGR A Control Circuit/Open — indicates an open or incomplete electrical circuit in the PCM's control feed to the EGR valve/solenoid labeled A. The PCM cannot detect proper control feedback when commanding the EGR actuator.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 1-3 hours

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Code

P0403

GWM P — Powertrain

- Malfunction in the exhaust gas recirculation system

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

Causes

  • Open or shorted wiring in EGR control circuit
  • Corroded, loose or damaged EGR connector
  • Failed EGR solenoid/actuator
  • Blown fuse or bad relay feeding the EGR circuit
  • Faulty PCM (less common)
  • Poor chassis or engine ground

Symptoms

  • Malfunction Indicator Lamp (MIL) illuminated
  • Rough idle or hesitation
  • Reduced engine performance or drivability issues
  • Higher NOx emissions / failed emissions test
  • Possible stalling at idle
  • Check engine light with related EGR faults

What to check

  • Read stored freeze frame and freeze data with a scan tool
  • Visual inspection of EGR valve, solenoid, wiring and connectors for damage or corrosion
  • Check relevant fuses and relays
  • Backprobe EGR connector while commanding with scan tool to observe signal
  • Measure continuity between PCM pin and EGR connector pin
  • Measure coil resistance of EGR solenoid (compare to spec or typical range)

Signal parameters

  • Key ON, engine OFF: 12 V supply should be present at the EGR solenoid power terminal (if applicable)
  • Control side: PCM may switch ground or battery feed depending on design — expected to show change when commanded
  • When commanded by scan tool: voltage or duty-cycle at control line should change from resting value to commanded value (0–100% duty or solid on/off)
  • Typical EGR solenoid coil resistance (varies by manufacturer): commonly ~10–50 Ω — check vehicle-specific spec
  • Open-circuit indication: infinite resistance (OL) between EGR actuator terminals or between actuator and PCM

Diagnostic algorithm

  1. Retrieve codes and freeze frame data. Note engine conditions when DTC set.
  2. Perform a visual inspection of the EGR valve/solenoid, harness, and connectors for damage, corrosion or heat damage.
  3. Check fuses/relays that supply the EGR circuits; replace if blown.
  4. With ignition ON (engine OFF), backprobe the EGR connector. Verify 12 V supply (if applicable) and good ground reference. Compare to wiring diagram for circuit polarity.
  5. Command the EGR valve ON/OFF with a scan tool while monitoring the control circuit voltage/duty. If PCM commands but no change at connector, suspect wiring between PCM and actuator.
  6. Remove connector and measure EGR actuator coil resistance. Open/infinite resistance = bad actuator.
  7. Check continuity between the PCM pin and the EGR connector pin. Repair any open or high-resistance sections.
  8. If wiring and actuator verify OK, check for intermittent faults by wiggle-testing harness under load/while commanded.
  9. Repair or replace faulty wiring, connector, fuse, relay or EGR actuator as required. After repair, clear codes and perform functional/road test to verify.
  10. If fault persists after harness and actuator replacement, consult manufacturer wiring diagrams and consider PCM/ground integrity testing or replacement.

Likely causes

  • Disconnected or broken harness between PCM and EGR valve
  • Pin pushed out or corrosion at connector causing open
  • EGR solenoid coil failed open
  • Fuse for emission solenoids blown
  • Connector damaged by heat/road debris

Fault status

⚠️ Status
EGR A Control Circuit/Open — indicates an open or incomplete electrical circuit in the PCM's control feed to the EGR valve/solenoid labeled A. The PCM cannot detect proper control feedback when commanding the EGR actuator.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 1-3 hours

Similar codes

P0400 P0401 P0402 P0404 P0405
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Code

P0403

HUMMER P — Powertrain

Exhaust Gas Recirculation (EGR) Solenoid Control Circuit

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

Causes

  • Open or shorted wiring in EGR control circuit
  • Corroded, loose or damaged EGR connector
  • Failed EGR solenoid/actuator
  • Blown fuse or bad relay feeding the EGR circuit
  • Faulty PCM (less common)
  • Poor chassis or engine ground

Symptoms

  • Malfunction Indicator Lamp (MIL) illuminated
  • Rough idle or hesitation
  • Reduced engine performance or drivability issues
  • Higher NOx emissions / failed emissions test
  • Possible stalling at idle
  • Check engine light with related EGR faults

What to check

  • Read stored freeze frame and freeze data with a scan tool
  • Visual inspection of EGR valve, solenoid, wiring and connectors for damage or corrosion
  • Check relevant fuses and relays
  • Backprobe EGR connector while commanding with scan tool to observe signal
  • Measure continuity between PCM pin and EGR connector pin
  • Measure coil resistance of EGR solenoid (compare to spec or typical range)

Signal parameters

  • Key ON, engine OFF: 12 V supply should be present at the EGR solenoid power terminal (if applicable)
  • Control side: PCM may switch ground or battery feed depending on design — expected to show change when commanded
  • When commanded by scan tool: voltage or duty-cycle at control line should change from resting value to commanded value (0–100% duty or solid on/off)
  • Typical EGR solenoid coil resistance (varies by manufacturer): commonly ~10–50 Ω — check vehicle-specific spec
  • Open-circuit indication: infinite resistance (OL) between EGR actuator terminals or between actuator and PCM

Diagnostic algorithm

  1. Retrieve codes and freeze frame data. Note engine conditions when DTC set.
  2. Perform a visual inspection of the EGR valve/solenoid, harness, and connectors for damage, corrosion or heat damage.
  3. Check fuses/relays that supply the EGR circuits; replace if blown.
  4. With ignition ON (engine OFF), backprobe the EGR connector. Verify 12 V supply (if applicable) and good ground reference. Compare to wiring diagram for circuit polarity.
  5. Command the EGR valve ON/OFF with a scan tool while monitoring the control circuit voltage/duty. If PCM commands but no change at connector, suspect wiring between PCM and actuator.
  6. Remove connector and measure EGR actuator coil resistance. Open/infinite resistance = bad actuator.
  7. Check continuity between the PCM pin and the EGR connector pin. Repair any open or high-resistance sections.
  8. If wiring and actuator verify OK, check for intermittent faults by wiggle-testing harness under load/while commanded.
  9. Repair or replace faulty wiring, connector, fuse, relay or EGR actuator as required. After repair, clear codes and perform functional/road test to verify.
  10. If fault persists after harness and actuator replacement, consult manufacturer wiring diagrams and consider PCM/ground integrity testing or replacement.

Likely causes

  • Disconnected or broken harness between PCM and EGR valve
  • Pin pushed out or corrosion at connector causing open
  • EGR solenoid coil failed open
  • Fuse for emission solenoids blown
  • Connector damaged by heat/road debris

Fault status

⚠️ Status
EGR A Control Circuit/Open — indicates an open or incomplete electrical circuit in the PCM's control feed to the EGR valve/solenoid labeled A. The PCM cannot detect proper control feedback when commanding the EGR actuator.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 1-3 hours

Similar codes

P0400 P0401 P0402 P0404 P0405
Repair manuals

Manual library for HUMMER

138

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Code

P0403

LAND ROVER P — Powertrain

Fault in the control of the position of the exhaust gas recirculation valve escape

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

Causes

  • Open or shorted wiring in EGR control circuit
  • Corroded, loose or damaged EGR connector
  • Failed EGR solenoid/actuator
  • Blown fuse or bad relay feeding the EGR circuit
  • Faulty PCM (less common)
  • Poor chassis or engine ground

Symptoms

  • Malfunction Indicator Lamp (MIL) illuminated
  • Rough idle or hesitation
  • Reduced engine performance or drivability issues
  • Higher NOx emissions / failed emissions test
  • Possible stalling at idle
  • Check engine light with related EGR faults

What to check

  • Read stored freeze frame and freeze data with a scan tool
  • Visual inspection of EGR valve, solenoid, wiring and connectors for damage or corrosion
  • Check relevant fuses and relays
  • Backprobe EGR connector while commanding with scan tool to observe signal
  • Measure continuity between PCM pin and EGR connector pin
  • Measure coil resistance of EGR solenoid (compare to spec or typical range)

Signal parameters

  • Key ON, engine OFF: 12 V supply should be present at the EGR solenoid power terminal (if applicable)
  • Control side: PCM may switch ground or battery feed depending on design — expected to show change when commanded
  • When commanded by scan tool: voltage or duty-cycle at control line should change from resting value to commanded value (0–100% duty or solid on/off)
  • Typical EGR solenoid coil resistance (varies by manufacturer): commonly ~10–50 Ω — check vehicle-specific spec
  • Open-circuit indication: infinite resistance (OL) between EGR actuator terminals or between actuator and PCM

Diagnostic algorithm

  1. Retrieve codes and freeze frame data. Note engine conditions when DTC set.
  2. Perform a visual inspection of the EGR valve/solenoid, harness, and connectors for damage, corrosion or heat damage.
  3. Check fuses/relays that supply the EGR circuits; replace if blown.
  4. With ignition ON (engine OFF), backprobe the EGR connector. Verify 12 V supply (if applicable) and good ground reference. Compare to wiring diagram for circuit polarity.
  5. Command the EGR valve ON/OFF with a scan tool while monitoring the control circuit voltage/duty. If PCM commands but no change at connector, suspect wiring between PCM and actuator.
  6. Remove connector and measure EGR actuator coil resistance. Open/infinite resistance = bad actuator.
  7. Check continuity between the PCM pin and the EGR connector pin. Repair any open or high-resistance sections.
  8. If wiring and actuator verify OK, check for intermittent faults by wiggle-testing harness under load/while commanded.
  9. Repair or replace faulty wiring, connector, fuse, relay or EGR actuator as required. After repair, clear codes and perform functional/road test to verify.
  10. If fault persists after harness and actuator replacement, consult manufacturer wiring diagrams and consider PCM/ground integrity testing or replacement.

Likely causes

  • Disconnected or broken harness between PCM and EGR valve
  • Pin pushed out or corrosion at connector causing open
  • EGR solenoid coil failed open
  • Fuse for emission solenoids blown
  • Connector damaged by heat/road debris

Fault status

⚠️ Status
EGR A Control Circuit/Open — indicates an open or incomplete electrical circuit in the PCM's control feed to the EGR valve/solenoid labeled A. The PCM cannot detect proper control feedback when commanding the EGR actuator.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 1-3 hours

Similar codes

P0400 P0401 P0402 P0404 P0405
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

P0403

MITSUBISHI P — Powertrain

EGR control circuit

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

Causes

  • Open or shorted wiring in EGR control circuit
  • Corroded, loose or damaged EGR connector
  • Failed EGR solenoid/actuator
  • Blown fuse or bad relay feeding the EGR circuit
  • Faulty PCM (less common)
  • Poor chassis or engine ground

Symptoms

  • Malfunction Indicator Lamp (MIL) illuminated
  • Rough idle or hesitation
  • Reduced engine performance or drivability issues
  • Higher NOx emissions / failed emissions test
  • Possible stalling at idle
  • Check engine light with related EGR faults

What to check

  • Read stored freeze frame and freeze data with a scan tool
  • Visual inspection of EGR valve, solenoid, wiring and connectors for damage or corrosion
  • Check relevant fuses and relays
  • Backprobe EGR connector while commanding with scan tool to observe signal
  • Measure continuity between PCM pin and EGR connector pin
  • Measure coil resistance of EGR solenoid (compare to spec or typical range)

Signal parameters

  • Key ON, engine OFF: 12 V supply should be present at the EGR solenoid power terminal (if applicable)
  • Control side: PCM may switch ground or battery feed depending on design — expected to show change when commanded
  • When commanded by scan tool: voltage or duty-cycle at control line should change from resting value to commanded value (0–100% duty or solid on/off)
  • Typical EGR solenoid coil resistance (varies by manufacturer): commonly ~10–50 Ω — check vehicle-specific spec
  • Open-circuit indication: infinite resistance (OL) between EGR actuator terminals or between actuator and PCM

Diagnostic algorithm

  1. Retrieve codes and freeze frame data. Note engine conditions when DTC set.
  2. Perform a visual inspection of the EGR valve/solenoid, harness, and connectors for damage, corrosion or heat damage.
  3. Check fuses/relays that supply the EGR circuits; replace if blown.
  4. With ignition ON (engine OFF), backprobe the EGR connector. Verify 12 V supply (if applicable) and good ground reference. Compare to wiring diagram for circuit polarity.
  5. Command the EGR valve ON/OFF with a scan tool while monitoring the control circuit voltage/duty. If PCM commands but no change at connector, suspect wiring between PCM and actuator.
  6. Remove connector and measure EGR actuator coil resistance. Open/infinite resistance = bad actuator.
  7. Check continuity between the PCM pin and the EGR connector pin. Repair any open or high-resistance sections.
  8. If wiring and actuator verify OK, check for intermittent faults by wiggle-testing harness under load/while commanded.
  9. Repair or replace faulty wiring, connector, fuse, relay or EGR actuator as required. After repair, clear codes and perform functional/road test to verify.
  10. If fault persists after harness and actuator replacement, consult manufacturer wiring diagrams and consider PCM/ground integrity testing or replacement.

Likely causes

  • Disconnected or broken harness between PCM and EGR valve
  • Pin pushed out or corrosion at connector causing open
  • EGR solenoid coil failed open
  • Fuse for emission solenoids blown
  • Connector damaged by heat/road debris

Fault status

⚠️ Status
EGR A Control Circuit/Open — indicates an open or incomplete electrical circuit in the PCM's control feed to the EGR valve/solenoid labeled A. The PCM cannot detect proper control feedback when commanding the EGR actuator.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 1-3 hours

Similar codes

P0400 P0401 P0402 P0404 P0405
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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