OBD2 · Powertrain
P06xx codes: control modules and output circuits
155 codes in this range, all generic — the same meaning on every make. The control modules themselves and the circuits they drive: internal memory and processor self-tests, sensor reference voltages, glow plugs, coolant pumps, relays and other outputs.
What usually causes codes in this area
- Low or unstable supply voltage and poor grounds
- A shorted sensor pulling down a shared reference voltage
- Software that needs an update
- Water damage or a failed module
Can you keep driving?
If the car runs normally, get it checked soon. A reference-voltage or processor code can come with stalling or limp mode — don’t rely on the car for long trips until it’s fixed.
All P06xx codes
| Code | Meaning |
|---|---|
| P0600 | Serial Communication Link |
| P0601 | Internal Control Module Memory Check Sum Error |
| P0602 | Control Module Programming Error |
| P0603 | Internal Control Module Keep Alive Memory (KAM) Error |
| P0604 | Internal Control Module Random Access Memory (RAM) Error |
| P0605 | Internal Control Module Read Only Memory (ROM) Error |
| P0606 | ECM/PCM Processor |
| P0607 | Control Module Performance |
| P0608 | Control Module VSS Output "A" |
| P0609 | Control Module VSS Output "B" |
| P060A | Internal Control Module Monitoring Processor Performance |
| P060B | Internal Control Module A/D Processing Performance |
| P060C | Internal Control Module Main Processor Performance |
| P060D | Internal Control Module Accelerator Pedal Position Performance |
| P060E | Internal Control Module Throttle Position Performance |
| P060F | Internal Control Module Coolant Temperature Performance |
| P0610 | Control Module Vehicle Options Error |
| P0611 | Fuel Injector Control Module Performance |
| P0612 | Fuel Injector Control Module Relay Control |
| P0613 | TCM Processor |
| P0614 | ECM/TCM Incompatible |
| P0615 | Starter Relay Circuit |
| P0616 | Starter Relay Circuit Low |
| P0617 | Starter Relay Circuit High |
| P0618 | Alternative Fuel Control Module KAM Error |
| P0619 | Alternative Fuel Control Module RAM/ROM Error |
| P061A | Internal Control Module Torque Performance |
| P061B | Internal Control Module Torque Calculation Performance |
| P061C | Internal Control Module Engine RPM Performance |
| P061D | Internal Control Module Engine Air Mass Performance |
| P061E | Internal Control Module Brake Signal Performance |
| P061F | Internal Control Module Throttle Actuator Controller Performance |
| P0620 | Generator Control Circuit |
| P0621 | Generator Lamp/L Terminal Circuit |
| P0622 | Generator Field/F Terminal Circuit |
| P0623 | Generator Lamp Control Circuit |
| P0624 | Fuel Cap Lamp Control Circuit |
| P0625 | Generator Field/F Terminal Circuit Low |
| P0626 | Generator Field/F Terminal Circuit High |
| P0627 | Fuel Pump "A" Control Circuit/Open |
| P0628 | Fuel Pump "A" Control Circuit Low |
| P0629 | Fuel Pump "A" Control Circuit High |
| P062A | Fuel Pump "A" Control Circuit Range/Performance |
| P062B | Internal Control Module Fuel Injector Control Performance |
| P062C | Internal Control Module Vehicle Speed Performance |
| P062D | Fuel Injector Driver Circuit Performance (Bank 1) |
| P062E | Fuel Injector Driver Circuit Performance (Bank 2) |
| P062F | Internal Control Module EEPROM Error |
| P0630 | VIN Not Programmed or Incompatible - ECM/PCM |
| P0631 | VIN Not Programmed or Incompatible - TCM |
| P0632 | Odometer Not Programmed - ECM/PCM |
| P0633 | Immobilizer Key Not Programmed - ECM/PCM |
| P0634 | PCM/ECM/TCM Internal Temperature Too High |
| P0635 | Power Steering Control Circuit |
| P0636 | Power Steering Control Circuit Low |
| P0637 | Power Steering Control Circuit High |
| P0638 | Throttle Actuator "A" Control Range/Performance (Bank 1) |
| P0639 | Throttle Actuator Control Range/Performance (Bank 2) |
| P063A | Generator Voltage Sense Circuit |
| P063B | Generator Voltage Sense Circuit Range/Performance |
| P063C | Generator Voltage Sense Circuit Low |
| P063D | Generator Voltage Sense Circuit High |
| P063E | Auto Configuration Throttle Input Not Present |
| P063F | Auto Configuration Engine Coolant Temperature Input Not Present |
| P0640 | Intake Air Heater Control Circuit |
| P0641 | Sensor Reference Voltage "A" Circuit/Open |
| P0642 | Sensor Reference Voltage "A" Circuit Low |
| P0643 | Sensor Reference Voltage "A" Circuit High |
| P0644 | Driver Display Serial Communication Circuit |
| P0645 | A/C Clutch Relay Control Circuit |
| P0646 | A/C Clutch Relay Control Circuit Low |
| P0647 | A/C Clutch Relay Control Circuit High |
| P0648 | Immobilizer Lamp Control Circuit |
| P0649 | Speed Control Lamp Control Circuit |
| P064A | Fuel Pump Control Module |
| P064B | Power Steering Control Module |
| P064C | Glow Plug Control Module |
| P064D | Internal Control Module O2 Sensor Processor Performance (Bank 1) |
| P064E | Internal Control Module O2 Sensor Processor Performance (Bank 2) |
| P0650 | Malfunction Indicator Lamp (MIL) Control Circuit |
| P0651 | Sensor Reference Voltage "B" Circuit/Open |
| P0652 | Sensor Reference Voltage "B" Circuit Low |
| P0653 | Sensor Reference Voltage "B" Circuit High |
| P0654 | Engine RPM Output Circuit |
| P0655 | Engine Hot Lamp Output Control Circuit |
| P0656 | Fuel Level Output Circuit |
| P0657 | Actuator Supply Voltage "A" Circuit/Open |
| P0658 | Actuator Supply Voltage "A" Circuit Low |
| P0659 | Actuator Supply Voltage "A" Circuit High |
| P065A | Generator System Performance |
| P065B | Generator Control Circuit Range/Performance |
| P065C | Generator Mechanical Performance |
| P0660 | Intake Manifold Tuning Valve Control Circuit/Open (Bank 1) |
| P0661 | Intake Manifold Tuning Valve Control Circuit Low (Bank 1) |
| P0662 | Intake Manifold Tuning Valve Control Circuit High (Bank 1) |
| P0663 | Intake Manifold Tuning Valve Control Circuit/Open (Bank 2) |
| P0664 | Intake Manifold Tuning Valve Control Circuit Low (Bank 2) |
| P0665 | Intake Manifold Tuning Valve Control Circuit High (Bank 2) |
| P0666 | PCM/ECM/TCM Internal Temperature Sensor Circuit |
| P0667 | PCM/ECM/TCM Internal Temperature Sensor Range/Performance |
| P0668 | PCM/ECM/TCM Internal Temperature Sensor Circuit Low |
| P0669 | PCM/ECM/TCM Internal Temperature Sensor Circuit High |
| P066A | Cylinder 1 Glow Plug Circuit Low |
| P066B | Cylinder 1 Glow Plug Circuit High |
| P066C | Cylinder 2 Glow Plug Circuit Low |
| P066D | Cylinder 2 Glow Plug Circuit High |
| P066E | Cylinder 3 Glow Plug Circuit Low |
| P066F | Cylinder 3 Glow Plug Circuit High |
| P0670 | Glow Plug Module Control Circuit |
| P0671 | Cylinder 1 Glow Plug Circuit |
| P0672 | Cylinder 2 Glow Plug Circuit |
| P0673 | Cylinder 3 Glow Plug Circuit |
| P0674 | Cylinder 4 Glow Plug Circuit |
| P0675 | Cylinder 5 Glow Plug Circuit |
| P0676 | Cylinder 6 Glow Plug Circuit |
| P0677 | Cylinder 7 Glow Plug Circuit |
| P0678 | Cylinder 8 Glow Plug Circuit |
| P0679 | Cylinder 9 Glow Plug Circuit |
| P067A | Cylinder 4 Glow Plug Circuit Low |
| P067B | Cylinder 4 Glow Plug Circuit High |
| P067C | Cylinder 5 Glow Plug Circuit Low |
| P067D | Cylinder 5 Glow Plug Circuit High |
| P067E | Cylinder 6 Glow Plug Circuit Low |
| P067F | Cylinder 6 Glow Plug Circuit High |
| P0680 | Cylinder 10 Glow Plug Circuit |
| P0681 | Cylinder 11 Glow Plug Circuit |
| P0682 | Cylinder 12 Glow Plug Circuit |
| P0683 | Glow Plug Control Module to PCM Communication Circuit |
| P0684 | Glow Plug Control Module to PCM Communication Circuit Range/Performance |
| P0685 | ECM/PCM Power Relay Control Circuit/Open |
| P0686 | ECM/PCM Power Relay Control Circuit Low |
| P0687 | ECM/PCM Power Relay Control Circuit High |
| P0688 | ECM/PCM Power Relay Sense Circuit/Open |
| P0689 | ECM/PCM Power Relay Sense Circuit Low |
| P068A | ECM/PCM Power Relay De-Energized Performance - Too Early |
| P068B | ECM/PCM Power Relay De-Energized Performance - Too Late |
| P068C | Cylinder 7 Glow Plug Circuit Low |
| P068D | Cylinder 7 Glow Plug Circuit High |
| P068E | Cylinder 8 Glow Plug Circuit Low |
| P068F | Cylinder 8 Glow Plug Circuit High |
| P0690 | ECM/PCM Power Relay Sense Circuit High |
| P0691 | Fan 1 Control Circuit Low |
| P0692 | Fan 1 Control Circuit High |
| P0693 | Fan 2 Control Circuit Low |
| P0694 | Fan 2 Control Circuit High |
| P0695 | Fan 3 Control Circuit Low |
| P0696 | Fan 3 Control Circuit High |
| P0697 | Sensor Reference Voltage "C" Circuit/Open |
| P0698 | Sensor Reference Voltage "C" Circuit Low |
| P0699 | Sensor Reference Voltage "C" Circuit High |
| P069A | Cylinder 9 Glow Plug Circuit Low |
| P069B | Cylinder 9 Glow Plug Circuit High |
| P069C | Cylinder 10 Glow Plug Circuit Low |
| P069D | Cylinder 10 Glow Plug Circuit High |
| P069E | Fuel Pump Control Module Requested MIL Illumination |
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