Engine Control Module (ECM): Controller

An ECM used for service (called a Controller) comes without a MEM-CAL. The MEM-CAL from the old ECM must be carefully removed and installed in the new ECM. Refer to REMOVAL, OVERHAUL & INSTALLATION article. If the MEM-CAL is missing, it will result in a no start and no run condition, and the ECM will not send data to the BCM. A current code B334 and a "System Problem" message on the DIC will result. Refer to BODY COMPUTER MODULE article in COMMUNICATION DEVICES.

The ECM performs the diagnostic function of the fuel control system. It can recognize operational problems, alert the driver through the "Engine Control System Fault" telltale, and store a code or codes which identify the problem areas to aid the technician in making repairs.