P0603

DTC P0603: Problem in TCM
2003 AT-PZEV (SULEV) and 2004-2005 AT-PZEV Models

NOTE:
^ Record all freeze data and review General Troubleshooting Information before you troubleshoot.
^ This code is caused by an electrical circuit problem and cannot be caused by a mechanical problem in the transmission.

1. Turn the ignition switch ON (II).
2. Shift the shift lever into the P or N position.
3. Turn the ignition switch OFF.
4. Disconnect TCM connector A (31P) for more than 5 seconds, then reconnect the connector.
5. Turn the ignition switch ON (II), and wait for more than 5 seconds.
6. Check that DTC P0603 recurs.
Is DTC P0603 indicated?
YES- Update the TCM if it does not have the latest software, or substitute a known-good TCM, then recheck. If the symptom/indication goes away with a known-good TCM, replace the original TCM.
NO- Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at TCM.