Vehicle system

Engine Computer and Output Circuit Codes

Codes for the engine computer itself: internal memory, self-test, sensor reference voltages, relays controlled by the computer and output circuits to actuators.

A code from this group does not automatically mean the computer has failed. Very often the cause is its power supply, a poor ground or a shorted actuator that forces it to protect the output.

Most searched codes in this system

What to check first

  1. Check the battery, the fuses and every engine ground before suspecting the computer.
  2. If a 5 V reference drops out, unplug sensors one at a time until it comes back.
  3. Look for water or corrosion in the module connectors.
  4. Ask whether there is a software update for your vehicle.

All codes in this system

124 codes, page 1 of 2

CodeMeaningSeverity
P0000 No Fault Code Stored or Empty Scan Tool Reading Low
P0512 Starter Request Circuit Medium
P0513 Incorrect Immobilizer Key High
P0514 Battery Temperature Sensor Circuit Range/Performance Low
P0515 Battery Temperature Sensor Circuit Low
P0516 Battery Temperature Sensor Circuit Low Low
P0517 Battery Temperature Sensor Circuit High Low
P0520 Engine Oil Pressure Sensor/Switch Circuit High
P0521 Engine Oil Pressure Sensor/Switch Circuit Range/Performance High
P0522 Engine Oil Pressure Sensor/Switch Circuit Low Voltage High
P0523 Engine Oil Pressure Sensor/Switch Circuit High Voltage High
P0524 Engine Oil Pressure Too Low Critical
P0526 Fan Speed Sensor Circuit Medium
P0527 Fan Speed Sensor Circuit Range/Performance Medium
P0528 Fan Speed Sensor Circuit No Signal Medium
P0529 Fan Speed Sensor Circuit Intermittent Medium
P0530 A/C Refrigerant Pressure Sensor Circuit Low
P0531 A/C Refrigerant Pressure Sensor Circuit Range/Performance Low
P0532 A/C Refrigerant Pressure Sensor Circuit Low Low
P0533 A/C Refrigerant Pressure Sensor Circuit High Low
P0534 A/C Refrigerant Charge Loss Low
P0535 A/C Evaporator Temperature Sensor Circuit Low
P0536 A/C Evaporator Temperature Sensor Circuit Range/Performance Low
P0537 A/C Evaporator Temperature Sensor Circuit Low Low
P0538 A/C Evaporator Temperature Sensor Circuit High Low
P0539 A/C Evaporator Temperature Sensor Circuit Intermittent Low
P0560 System Voltage High
P0561 System Voltage Unstable Medium
P0562 System Voltage Low High
P0563 System Voltage High High
P0600 Serial Communication Link Malfunction Medium
P0601 Internal Control Module Memory Check Sum Error High
P0602 Control Module Programming Error Medium
P0603 Internal Control Module Keep Alive Memory (KAM) Error Medium
P0604 Internal Control Module Random Access Memory (RAM) Error Medium
P0605 Internal Control Module Read Only Memory (ROM) Error Medium
P0606 Control Module Processor Fault High
P0607 Control Module Performance Medium
P0608 Control Module VSS Output A Malfunction Low
P0609 Control Module VSS Output B Malfunction Low
P0610 Control Module Vehicle Options Error Medium
P0611 Fuel Injector Control Module Performance High
P0612 Fuel Injector Control Module Relay Control High
P0613 TCM Processor High
P0614 ECM/TCM Incompatible Medium
P0615 Starter Relay Circuit High
P0616 Starter Relay Circuit Low High
P0617 Starter Relay Circuit High High
P0618 Alternative Fuel Control Module KAM Error Medium
P0619 Alternative Fuel Control Module RAM/ROM Error Medium
P0620 Generator Control Circuit Malfunction High
P0621 Generator Lamp "L" Control Circuit Malfunction Low
P0622 Generator Field "F" Control Circuit Malfunction High
P0623 Generator Lamp Control Circuit Malfunction Low
P0624 Fuel Cap Lamp Control Circuit Low
P0625 Generator Field/F Terminal Low High
P0626 Generator Field/F Terminal High High
P0630 VIN Not Programmed or Mismatch - ECM/PCM High
P0631 VIN Not Programmed or Mismatch - TCM Medium
P0632 Odometer Not Programmed - ECM/PCM Medium
P0633 Immobilizer Key Not Programmed - ECM/PCM High
P0634 PCM/ECM/TCM Internal Temperature Too High Medium
P0641 Sensor Reference Voltage "A" Circuit/Open High
P0642 Sensor Reference Voltage "A" Circuit Low High
P0643 Sensor Reference Voltage "A" Circuit High High
P0644 Driver Display Serial Communication Circuit Low
P0645 A/C Clutch Relay Control Circuit Low
P0646 A/C Clutch Relay Control Circuit Low Low
P0647 A/C Clutch Relay Control Circuit High Low
P0648 Immobilizer Lamp Control Circuit Low
P0649 Speed Control Lamp Control Circuit Low
P0650 Malfunction Indicator Lamp (MIL) Control Circuit Low
P0651 Sensor Reference Voltage "B" Circuit/Open High
P0652 Sensor Reference Voltage "B" Circuit Low High
P0653 Sensor Reference Voltage "B" Circuit High High
P0654 Engine RPM Output Circuit Low
P0655 Engine Hot Lamp Output Control Circuit Low
P0656 Fuel Level Output Circuit Low
P0657 Actuator Supply Voltage "A" Circuit/Open High
P0658 Actuator Supply Voltage "A" Circuit Low High
P0659 Actuator Supply Voltage "A" Circuit High High
P0666 PCM/ECM/TCM Internal Temperature Sensor Circuit Low
P0667 PCM/ECM/TCM Internal Temperature Sensor Range/Performance Low
P0668 PCM/ECM/TCM Internal Temperature Sensor Circuit Low Low
P0669 PCM/ECM/TCM Internal Temperature Sensor Circuit High Low
P0685 ECM/PCM Power Relay Control Circuit/Open High
P0686 ECM/PCM Power Relay Control Circuit Low High
P0687 ECM/PCM Power Relay Control Circuit High High
P0688 ECM/PCM Power Relay Sense Circuit/Open High
P0689 ECM/PCM Power Relay Sense Circuit Low High
P0690 ECM/PCM Power Relay Sense Circuit High High
P0691 Fan 1 Control Circuit Low High
P0692 Fan 1 Control Circuit High High
P0693 Fan 2 Control Circuit Low High
P0694 Fan 2 Control Circuit High High
P0695 Fan 3 Control Circuit Low Medium
P0696 Fan 3 Control Circuit High Medium
P0697 Sensor Reference Voltage C Circuit/Open High
P0698 Sensor Reference Voltage C Circuit Low High
P0699 Sensor Reference Voltage C Circuit High High

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