GM 88999170 Engine Control Module Assembly (Remanufacture)

To remove or install the Electronic Control Module make sure that the ignition switch is off and do not connect or disconnect any connectors when it is on. The ECM is fixed beneath the instrument panel. Start with the removal of the negative terminal of the battery being careful to disable the locking of the blade connector on models with the Delco Loe II audio system. Pull off the glove box to reach the ECM and then remove the retaining bolts to ease out the ECM with the assistance of fingers to disconnected the electrical connectors. For MEM-CAL replacement wherein one MEM-CAL can be utilized for multiple vehicles, the MEM-CAL is embedded in the ECM and carries vehicle data. When changing MEM-CAL one has to make sure to have a correct number for an MEM-CAL as when you get an ECM from a dealer than it does not come with MEM-CAL. Locate and take off the MEM-CAL access cover After exercising this step, the retaining clips should be put back while pulling out the MEM-CAL off socket without causing damage. Ensure that the numbers appearing on the earlier and the newer ECMs or MEM-CALs tally. To install the new MEM-CAL, press only on the ends and when the notches are to the socket, the clips will engage. After installation, check for right seating position by starting the ignition then putting the diagnostic mode and looking at the message code then look for Code 12 that shows that no other codes are present. When trouble codes come up or the light illuminates, the switch should be in its correct position if the MEM-CAL is not defective.

A calibrator or Programmable Read Only Memory (PROM) is integrated within the ECM.

First, remove the PROM access cover using a rocker type PROM removal tool to avoid damaging the PROM or socket. Check that the part number of the new PROM matches the old one without removing it from the carrier.