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 P0606: Control Module Internal Performance
Circuit/System 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.
Conditions for Running the DTC
P0601
The checksum calculation at power down in the last drive cycle completely finished. DTC P0601 runs once an ignition cycle.
P0602
The ignition is ON, with the engine OFF. DTC P0602 runs continuously.
P0604
The read/write test at power down in the last drive cycle completely finished. DTC P0604 runs once an ignition cycle.
P0606
DTC P0606 runs continuously with ignition ON or engine operating.
Conditions for Setting the DTC
P0601
The ECM detects the incorrect read only memory (ROM) checksum for more than 30 seconds.
P0602
The ECM detects that programming is incomplete for more than 1 second.
P0604
The ECM detects random access memory (RAM) errors for more than 5 seconds.
P0606
The ECM detects an internal condition for more than 5 seconds.
Action Taken When the DTC Sets
DTCs P0601, P0602, P0604, and P0606 are Type A DTCs.
Conditions for Clearing the DTC
DTCs P0601, P0602, P0604, and P0606 are Type A DTCs.
Reference Information
DTC Type Reference
Circuit/System Verification
- Ignition ON, observe the DTC information with a scan tool. DTC P0601, P0602, P0604, and P0606 should not set.
- Operate the vehicle within the conditions for running the DTC. You may also operate the vehicle within the conditions that you observed in the Freeze Frame/Failure Records data.
| ⇒ | If DTC P0602 failed this ignition, program the ECM. If the DTC resets, replace the ECM. |
| ⇒ | If DTC P0606 is set with P0638, P2101, or P2119, refer to Diagnostic Trouble Code (DTC) List - Vehicle for further diagnosis. |
| ⇒ | If DTC P0606 failed this ignition, clear the DTCs with a scan tool and verify the DTC does not reset. If DTC resets, replace the ECM. |
| ⇒ | If DTC P0601 or P0604 failed this ignition, replace the ECM. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Control Module References for engine control module replacement, setup, and programming
