For 1990-2009 cars

### Diagnostic Instructions

• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

• | Review Strategy Based Diagnosis for an overview of the diagnostic approach.

• | Diagnostic Procedure Instructions provides an overview of each diagnostic category.

### DTC Descriptors

DTC P0601: Control Module Read Only Memory (ROM)
DTC P0602: Control Module Not Programmed
DTC P0604: Control Module Random Access Memory (RAM)
DTC P0605: Control Module Programming Read Only Memory (ROM)
DTC P0606: Control Module Internal Performance
DTC P0607: Control Module Performance
DTC P061A: Control Module Torque Performance
DTC P061B: Control Module Torque Calculation Performance
DTC P061C: Control Module Engine Speed Performance
DTC P2610: Control Module Ignition OFF Timer Performance

### 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.

### Conditions for Running the DTCs

#### P0601

• | The ignition switch is in Run or Crank.

• | The check sum calculation at power-down in the last drive cycle had completely finished.

• | DTC P0601 runs once per ignition cycle when the above condition is met.

#### P0602

• | The ignition switch is in Run or Crank.

• | DTC P0602 runs once per ignition cycle.

#### P0604

• | The ignition switch is in Run or Crank.

• | The read/write test at power-down in the last drive cycle had completely finished.

• | DTC P0604 runs once per ignition cycle when the above condition is met.

#### P0605

• | The ignition switch is in Run or Crank.

• | DTC P0605 runs continuously when the above condition is met.

#### P0606

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

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

#### P0607

• | The engine is running or cranking.

• | DTC P0607 runs continuously when the above condition is met.

#### P061A

• | The ignition switch is in the Run or Crank position.

• | DTC P061A runs continuously when the above condition is met.

#### P061B

• | The engine is running or cranking.

• | DTC P061B runs continuously when the above condition is met.

#### P061C

• | The engine is running.

• | The engine speed is more than 1,760 RPM.

• | DTC P061C runs continuously when the above condition is met.

#### P2610

• | The ECM is powered down.

• | DTC P2610 runs once per ignition cycle.

| OR

• | The ECM is powered up with the ignition switch in the Run or Crank position.

• | The engine OFF timer value is less than or greater than an internal reference counter during an 2-second interval.

• | DTC P2610 runs continuously when the above conditions are met.

### Conditions for Setting the DTCs

The ECM detects an internal failure or incomplete programming for more than 10 seconds.

### Actions Taken When the DTC Sets

• | DTCs P0601, P0602, P0604, P0606, P061A, P061B, P061C are Type A DTCs.

• | DTC P2610 is a Type B DTC.

### Conditions for Clearing the MIL/DTC

• | DTCs P0601, P0602, P0604, P0606, P061A, P061B, P061C are Type A DTCs.

• | DTC P2610 is a Type B DTC.

### Reference Information

#### Schematic Reference

Engine Controls Schematics

#### Connector End View Reference

Component Connector End Views

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

#### DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

#### Scan Tool Reference

Control Module References for scan tool information

### Circuit/System Testing

1. Observe the DTCs with the scan tool.

⇒ | If DTC P0602 is set, attempt to program the ECM before replacing the ECM. Refer to Control Module References.

⇒ | If DTC P0602 resets, replace the ECM.

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

• | A short

• | An open

• | High resistance

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

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for ECM replacement, programming and setup