Diagnostic Instructions
DTC Descriptors
DTC P0601: Control Module Read Only Memory (ROM)
DTC P0602: Control Module Not Programmed
DTC P1607: Control Module Ignition Off Timer Performance.
DTC P1650: Control Module Internal Performance.
DTC P1655: 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 and P0602
| • | The ignition is ON, or the engine is operating. |
| • | The DTCs run once an ignition cycle. |
P0607
| • | The ignition voltage is greater than 11 volts. |
| • | The DTC runs continuous once the above conditions are met. |
P1607
| • | The ignition is ON with the engine OFF. |
| • | The DTC runs once an ignition cycle. |
P1650 and P1655
| • | The ignition is ON, or the engine is operating. |
| • | 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.
P0602
The ECM detects that programming is incomplete for greater than 1 second.
P0607
The ECM detects an internal condition for greater than 3 seconds.
P1607, P1650 and P1655
The ECM detects a low power counter error for greater than 3 seconds.
Action Taken When the DTC Sets
| • | DTCs P0601 and P0602 are Type A DTCs. |
| • | DTC P1655 is a Type B DTC. |
| • | DTCs P0607, P1607, and P1650 are Type C DTCs. |
Conditions for Clearing the DTC
| • | DTCs P0601 and P0602 are Type A DTCs. |
| • | DTC P1655 is a Type B DTC. |
| • | DTCs P0607, P1607, and P1650 are Type C DTCs. |
Reference Information
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, P0602, P1607, P1650 or P1655 should not set.
| ⇒ | If any DTCs 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.
