For 1990-2009 cars only
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 P0604: Control Module Random Access Memory (RAM)
DTC P0605: Control Module Programming Read Only Memory (ROM)
Circuit/System Description
This diagnostic applies to internal microprocessor integrity conditions within the engine control module (ECM).
Conditions for Running the DTC
| • | The ignition is ON or the engine is running. |
| • | The DTCs run once an ignition cycle. |
Conditions for Setting the DTC
P0601
The ECM detects that the checksum calculation does not match the expected checksum.
P0604 or P0605
The ECM detects an internal condition for more than 3 seconds.
Action Taken When the DTC Sets
DTCs P0601, P0604, and P0605 are Type B DTCs.
Conditions for Clearing the DTC
DTCs P0601, P0604, and P0605 are Type B DTCs.
Reference Information
Description and Operation
Engine Control Module Description
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Circuit/System Testing
Ignition ON, observe the DTC information with a scan tool. DTCs P0601, P0604, or P0605 should not set.
| ⇒ | If DTCs P0601, P0604, or P0605 failed this ignition, replace the ECM. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Control Module References for ECM replacement, setup, and programming.
