P0603

DTC P0603 Internal Control Module Keep Alive Memory (KAM) Error





Circuit Description
A normal function of the Transmission Control Module (TCM) programming is to perform an internal check that verifies the integrity of the KAM memory allocations.
The DTC P0603 sets when the keep alive memory (KAM) is not operating correctly when checked on initialization.
An area of KAM is failed a read/ write test.

Conditions for Setting the DTC
- The checksum of the current regulator data will be tested. If the checksum is not OK, then the error bit will be set.
- If writing to FLASH during power latch phase failed.
- Each of the flash blocks has its own status which is located at the beginning of the each flash block and the status of the FLASH blocks do not fit together.
- System voltage is too high or too low.
- Transaxle input voltage is too high or too low.
- Immediately after the above condition occurs.

Action Taken When the DTC Sets
- The Malfunction Indicator Lamp (MIL) will illuminate.
- The TCM will record operating conditions at the time the diagnostic fails. This information will be stored in the Failure Records buffer.
- Adopt Emergency/ Substitute mode and constant 4th gear by hydraulic control.
- After ignition OFF/ON: 3rd gear by hydraulic control. Possible P, R and N also possible.
- Power supply cut off to the EDS valve.

Conditions for Clearing the MIL/DTC
- The MIL will turn OFF when the malfunction has not occurred after three-ignition cycle.
- A history DTC will clear after 40 consecutive warm up cycles without a fault.
- Using a scan tool can clear history DTCs.

Diagnostic Aids

Steps 1-5:

- When DTC P0603 sets, the possible cause of fault could be TCM.