Transmission Diagnosis

The Transaxle Control Module (TCM) contains Random Access Memory (RAM). The TCM sends information from the non-volatile memory to RAM. When the TCM detects a wrong copy of information from the non-volatile memory to the RAM, DTC P0603 sets. P0603 is a type A DTC.

DTC PARAMETERS
DTC P0603 Will set if TCM detects a non-volatile memory checksum failure.

DIAGNOSTIC AIDS
The only possible repair is TCM replacement. Remember to program the replacement TCM with the correct software and calibration.