Pcm Removal & Replacement

NOTE: The PCM in 2003 has a self-shutdown feature that writes data to memory and does diagnostic functions for up to 18 hours after you turn the ignition switch to LOCK. To keep from permanently damaging the PCM or losing data, do this procedure before unplugging the PCM:

With ignition switch in ON position, connect PGM tester to DLC. Power on tester.
Select CURRENT DATA to establish communication between PGM tester and PCM. Communication must be established between tester and PCM before turning ignition switch to LOCK position.
Turn ignition switch to LOCK position.
Exit to MENU. Select SCS, and follow the screen prompts to ground the 16-pin DLC. DO NOT press EXIT key or you will drop out of SCS mode. Once DLC is properly grounded, you can safely unplug the PCM.

Using this procedure to short the SCS stops the data writing process that normally occurs right after the ignition is turned to LOCK position. If you short the SCS before turning the ignition switch to LOCK, the ECM/PCM goes into 1-trip mode, which does not stop the data writing process nor prevent ECM/PCM damage. If you disconnect the negative battery cable before unplugging the ECM/PCM, damage will not occur but ECM/PCM will lose CKP pattern and idle learn data. For CKP pattern learn procedure, see CKP PATTERN LEARN PROCEDURE . For idle learn procedure, see PCM IDLE LEARN PROCEDURE .