Engine Control Module: Testing and Inspection

NOTE: Before replacing the Powertrain Control Module (PCM) or Engine Control Module (ECM), be certain to check the related component/circuit integrity for failures not detected due to a double fault in the circuit. Most PCM/ECM driver/control circuit failures are caused by internal component failures (i.e. relays and solenoids) and shorted circuits (i.e. pull-ups, drivers, and switched circuits). These failures are difficult to detect when a double fault has occurred and only one DTC has been set.

When a Powertrain Control Module (PCM) for a gasoline engine, or a Engine Control Module for a diesel engine and the Sentry Key Immobilizer Module (SKIM) on vehicles equipped with the Sentry Key Immobilizer System (SKIS) are replaced at the same time, perform the following steps in order:
1. Program the new PCM/ECM.
2. Program the new SKIM.
3. Replace all ignition keys and program them into the new SKIM.


The SKIS Secret Key is an ID code that is unique to each SKIM. This code is programmed and stored in the SKIM, the PCM/ECM, and each ignition key transponder chip. When the PCM/ECM or SKIM is replaced, it is necessary to program the Secret Key into the new modules using a diagnostic scan tool. Follow the programming steps outlined in the diagnostic scan tool menu for the module being replaced as appropriate.

NOTE:
- Be certain to enter the correct country code for the SKIM. If the incorrect country code is programmed into the SKIM, it cannot be changed and the SKIM must be replaced.
- If the PCM/ECM and the SKIM are replaced at the same time, all vehicle ignition keys will need to be replaced and the new keys programmed into the new SKIM.
- Programming the PCM/ECM or SKIM is done using a diagnostic scan tool and a PIN to enter secure access mode. If three attempts are made to enter secure access mode using an incorrect PIN, secure access mode will be locked out for one hour. To exit this lockout mode, turn the ignition to the RUN position for one hour then enter the correct PIN. (Ensure all accessories are turned OFF. Also monitor the battery state and connect a battery charger if necessary).