For 1990-2009 cars

### DTC Descriptors

DTC P0601: Control Module Read Only Memory (ROM) Error
DTC P0602: Control Module Not Programmed
DTC P0603: Control Module Long Term Memory Reset
DTC P0604: Internal Control Module Random Access Memory (RAM) Error
DTC P0606: Electronic Control Unit (ECU) - Malfunction
DTC P0607: Electronic Control Unit (ECU) - Performance
DTC P062F: ECU EEPROM Error
DTC P2610: Control Module Ignition Off Timer Performance

### Diagnostic Fault Information

Always perform the Diagnostic System Check - Vehicle , prior to using this diagnostic procedure.

### Description

This diagnostic applies to internal microprocessor integrity conditions within the engine control module (ECM). This diagnostic also addresses if the ECM is not programmed.

The ECM monitors its ability to read and write to the memory. It also monitors a timing function.

### Circuit/System Testing for the DTC

1. Observe the DTCs with the scan tool.

⇒ | If DTC P0602 is set, attempt to program the ECM before replacing the ECM. Refer to Service Programming System (SPS) Notice .

⇒ | If DTC P0602 resets, replace the ECM.

2. Test the voltage and ground inputs to the ECM for the following:

• | A short to ground.

• | An open/high resistance.

⇒ | If all circuits test OK, replace the ECM.

### Conditions for Running the DTCs

#### P0601

• | The ignition switch is in Run or Crank.

• | DTC P0601 runs continuously when the above condition is met.

#### P0602

• | The ignition switch is in Run or Crank.

• | DTC P0602 runs once per ignition cycle.

#### P0603

• | The ignition switch is in Run or Crank.

• | DTC P0603 runs once per ignition cycle.

#### P0604

• | The ignition switch is in Run or Crank.

• | DTC P0604 runs continuously when the above condition is met.

#### P0606

• | The ignition switch is in the Unlock/Accessory, Run or Crank positions.

• | The system voltage is more than 5.23 volts.

• | DTC P0606 runs continuously when the above conditions are met.

#### P0607

• | The ignition switch is in Unlock/Accessory, Run or Crank.

• | The system voltage is more than 5.23 volts.

• | DTCs P0601, P0602, P0603, P0604, P0606, P062F, P0641, P0651, P2610 are not set

• | DTC P0607 runs continuously when the above conditions are met.

#### P062F

• | The ignition is ON.

• | DTC P062F runs once per ignition cycle.

#### P2610

• | The ECM is powered down.

• | The intake air temperature is between -40°C (-40°F) and 125°C (257°F).

• | DTC P2610 runs once per ignition cycle.

### Conditions for Setting the DTCs

The ECM detects an internal failure or incomplete programming for more than 14 seconds.

### Action Taken when the DTC Sets

DTCs P0506 or P0507 are type A DTCs.

### Conditions for Clearing the MIL/DTC

DTCs P0506 or P0507 are type A DTCs.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for ECM replacement, programming and setup