Check-engine codes
What does my check-engine code mean?
Plain-English explanations for OBD-II trouble codes: what the code means, the most likely causes, symptoms, and how much labour a repair usually takes.
P0 codes · Powertrain (generic)
- P0644Driver Display Serial Communication Circuit
- P0645A and C Clutch Relay Control Circuit
- P0646A and C Clutch Relay Control Circuit Low
- P0647A and C Clutch Relay Control Circuit High
- P0648Immobilizer Lamp Control Circuit
- P0649Speed Control Lamp Control Circuit
- P064AFuel Pump Control Module A
- P064BPTO Control Module
- P064CGlow Plug Control Module 1
- P064DInternal Control Module O2 Sensor Processor Performance Bank 1
- P064EInternal Control Module O2 Sensor Processor Performance Bank 2
- P064FUnauthorized Software or Calibration Detected
- P0650Malfunction Indicator Lamp Control Circuit Malfunction
- P0651Sensor Reference Voltage B Circuit Open
- P0652Sensor Reference Voltage B Circuit Low
- P0653Sensor Reference Voltage B Circuit High
- P0654Engine RPM Output Circuit Open
- P0655Engine Hot Lamp Output Control Circuit
- P0656Fuel Level Output Circuit
- P0657Actuator Supply Voltage A Circuit Open
- P0658Actuator Supply Voltage A Circuit Low
- P0659Actuator Supply Voltage A Circuit High
- P065AGenerator System Performance
- P065BGenerator A Control Circuit Range or Performance
- P065CGenerator A Mechanical Performance
- P065DReductant System Malfunction Lamp Control Circuit
- P065EIntake Manifold Tuning Valve Performance Bank 1
- P065FIntake Manifold Tuning Valve Performance Bank 2
- P0660Intake Manifold Tuning Valve Control Circuit Open Bank 1
- P0661Intake Manifold Tuning Valve Control Circuit Low Bank 1
- P0662Intake Manifold Tuning Valve Control Circuit High Bank 1
- P0663Intake Manifold Tuning Valve Control Circuit Open Bank 2
- P0664Intake Manifold Tuning Valve Control Circuit Low Bank 2
- P0665Intake Manifold Tuning Valve Control Circuit High Bank 2
- P0666Control Module Internal Temperature Sensor A Circuit
- P0667Control Module Internal Temperature Sensor A Range or Performance
- P0668Control Module Internal Temperature Sensor A Circuit Low
- P0669Control Module Internal Temperature Sensor A Circuit High
- P066ACylinder 1 Glow Plug Control Circuit Low
- P066BCylinder 1 Glow Plug Control Circuit High
- P066CCylinder 2 Glow Plug Control Circuit Low
- P066DCylinder 2 Glow Plug Control Circuit High
- P066ECylinder 3 Glow Plug Control Circuit Low
- P066FCylinder 3 Glow Plug Control Circuit High
- P0670Glow Plug Module Control Circuit
- P0671Cylinder 1 Glow Plug Circuit
- P0672Cylinder 2 Glow Plug Circuit
- P0673Cylinder 3 Glow Plug Circuit
- P0674Cylinder 4 Glow Plug Circuit
- P0675Cylinder 5 Glow Plug Circuit
- P0676Cylinder 6 Glow Plug Circuit
- P0677Cylinder 7 Glow Plug Circuit
- P0678Cylinder 8 Glow Plug Circuit
- P0679Cylinder 9 Glow Plug Circuit Open
- P067ACylinder 4 Glow Plug Control Circuit Low
- P067BCylinder 4 Glow Plug Control Circuit High
- P067CCylinder 5 Glow Plug Control Circuit Low
- P067DCylinder 5 Glow Plug Control Circuit High
- P067ECylinder 6 Glow Plug Control Circuit Low
- P067FCylinder 6 Glow Plug Control Circuit High
- P0680Cylinder 10 Glow Plug Circuit Open
- P0681Cylinder 11 Glow Plug Circuit Open
- P0682Cylinder 12 Glow Plug Circuit Open
- P0683Glow Plug Control Module 1 to PCM Communication Circuit
- P0684Glow Plug Control Module 1 to PCM Communication Range or Performance
- P0685ECM or PCM Power Relay Control Circuit Open
- P0686ECM/PCM Power Relay Control Circuit Open
- P0687ECM/PCM Power Relay Sense Circuit Open
- P0688ECM/PCM Power Relay Sense Circuit High
- P0689ECM or PCM Power Relay Sense Circuit Low
- P068AECM or PCM Power Relay De-Energized Performance Too Early
- P068BECM or PCM Power Relay De-Energized Performance Too Late
- P068CCylinder 7 Glow Plug Control Circuit Low
- P068DCylinder 7 Glow Plug Control Circuit High
- P068ECylinder 8 Glow Plug Control Circuit Low
- P068FCylinder 8 Glow Plug Control Circuit High
- P0690ECM or PCM Power Relay Sense Circuit High
- P0691Cooling Fan 1 Control Circuit Low
- P0692Cooling Fan 1 Control Circuit High
- P0693Cooling Fan 2 Control Circuit Low
- P0694Cooling Fan 2 Control Circuit High
- P0695Fan 3 Control Circuit Low
- P0696Fan 3 Control Circuit High
- P0697Sensor Reference Voltage C Circuit Open
- P0698Sensor Reference Voltage C Circuit Low
- P0699Sensor Reference Voltage C Circuit High
- P069ACylinder 9 Glow Plug Control Circuit Low
- P069BCylinder 9 Glow Plug Control Circuit High
- P069CCylinder 10 Glow Plug Control Circuit Low
- P069DCylinder 10 Glow Plug Control Circuit High
- P069EFuel Pump Control Module Requested MIL Illumination
- P069FThrottle Actuator Control Lamp Control Circuit
- P06A0Variable A/C Compressor Control Circuit
- P06A1Variable A/C Compressor Control Circuit Low
- P06A2Variable A/C Compressor Control Circuit High
- P06A3Sensor Reference Voltage D Circuit Open
- P06A4Sensor Reference Voltage D Circuit Low
- P06A5Sensor Reference Voltage D Circuit High
- P06A6Sensor Reference Voltage A Circuit Range or Performance
- P06A7Sensor Reference Voltage B Circuit Range or Performance
Code data: OBDex open dataset (CC0), reviewed and rewritten for drivers. Always confirm a diagnosis before replacing parts.