Pontiac 88999112 Engine Control Module

The ECM being the third is situated behind the padded console which is installed in between the seat and the backrest. Start by removing the negative battery terminal and to avoid any shorting of the ECM connectors the ignition should be turned off. Take off the padded centre console; release the electrical connectors and fasten the ECM nuts; there are big connectors at the bottom of the module which has to be unplugged before the module is unbolted from the four mounting bolts. Very gently remove the ECM and then transfer 7ROM from the old one to the new ECM. When replacing the existing PROM with a new one, in the old ECM, use a rocker type PROM remover in order to avoid damaging the PROM or socket while removing the access cover. Please ensure that the new PROM's number matches the old one without having to take it out from the carrier. Place the new PROM carrier in the ECM socket in proper alignment to the pinheads of the PROM and press it down without touching the PROM. The access cover must be replaced and locked unto the screws while the ECM is mounted on its support bracket and the electrical connectors reconnected. When the padded console has been reinstalled, start the car and go to the diagnostics testing mode; readings must show that Code 12 has been repeated several times with no other code meaning that the PROM has been installed correctly. If an illustration, trouble code 51 appears or the Service Engine Soon light is still on, make sure that the PROM is installed properly, or it on the wrong side, or the pins are bent, or else it is bad. This problem may be solved by the firm pressing on the carrier, though it must be fully seated. Do not perform this maneuver because installing the PROM backwards will fry the circuitry in the microcontroller. If any of the pins are bent the user should straighten them but in case they are broken then the PROM should be replaced with a new one.