REMOVAL & INSTALLATION
| CAUTION | To prevent damage to ECM, ignition must be off before disconnecting or reconnecting any ECM power source (i.e.; battery, ECM connectors, ECM fuse, jumper cables, etc.). Replacement ECM's do not come with a "MEM-CAL" installed. Use "MEM-CAL" from original ECM. |
| CAUTION | When certain materials rub together, a transfer of electrons from one material to another may occur under special conditions. This results in an electrostatic charge (static electricity) being built up in one of the materials. When any conducting material comes in contact with the charged material, electrostatic discharge occurs, transferring electrons to the third material. Since electronic components used in control systems are designed to carry very low voltages, as little as a 30-volt charge created by static electricity can cause a total or degrading failure in ECM or other electronic components containing integrated circuits. Before servicing ECM, ground yourself and ground the work area to discharge stored electricity. |
| Movement Causing Charge | % Relative Humidity 10-20 | % Relative Humidity 65-90 |
|---|---|---|
| Handling Clear Plastic Bag | 20,000 | 1200 |
| Sliding Across Velour Seat | 15,000 | 400 |
| Walking Across Tile/Vinyl | 12,000 | 50 |
| Handling Vinyl Envelope | 7000 | 600 |
STATIC CHARGE (VOLTS)
| CAUTION | DO NOT remove part from packaging until ready to install. Ground any static proof package PRIOR to opening. DO NOT touch electrical terminals of components unless properly grounded. DO NOT lay electrical components on car seat, carpeting or dashboard. Use electrostatic protection mat and ground strap whenever possible. (Scheme 1) |
Servicing ECM Using 3M Anti-Static Mat. Scheme 1
ECM/MEM-CAL - 1988-91 MODELS WITH MEM-CAL
Note. To prevent damage to ECM, ignition must be off before disconnecting or reconnecting any ECM power source (i.e.; battery, ECM connectors, ECM fuse, jumper cables, etc.).
Note. The following steps are courtesy of General Motors Technical Service Bulletin No. T-91-95, June, 1991 & Technical Service Bulletin No. 6E-18, June, 1991.
Problem
When installing a service replacement ECM, the use of incorrect MEM-CAL installation procedures may cause the ECM to fail before it can be installed in the vehicle. This condition may appear as if the ECM were defective when it was shipped to the dealership when, in fact, it was damaged while being installed. In addition, this condition may also occur when installing as "updated" service into the vehicle's original equipment ECM. Excessive vertical force may be generated in two ways
- Incorrect MEM-CAL installation procedure.
- Interference between MEM-CAL and cover.
Repair
To repair this condition use the following procedure. This procedure supersedes any instructions regarding MEM-CAL installation dated prior to September, 1990.
- Inspect the MEM-CAL to determine if a cork spacer is glued to the top side of the MEM-CAL assembly. If so, remove it prior to installation.
- Align small notches with matching notches in the ECM MEM-CAL socket.
- VERY GENTLY press down on the ends of the MEM-CAL until the locking levers are rotated toward the sides of the MEM-CAL. NOTE: To avoid ECM damage, do not press on the ends of the MEM-CAL unit until the levers snap into place. DO NOT use any vertical force beyond the minimum required to engage the MEM-CAL into its socket.
- While continuing light pressure on the ends of the MEM-CAL, use your index fingers to press the locking levers inward until they are snapped into place. Listen for click.
- Install MEM-CAL cover and install ECM in vehicle.
Note. If diagnostic procedures require replacement of ECM, ensure ECM and PROM part numbers are correct. Service ECM DOES NOT contain a PROM. Old PROM must be installed in service ECM. Part number verification is critical for proper vehicle operation.
Installing "MEM-CAL" Assembly In ECM. Scheme 2
Remove glove compartment module. Remove BCM-to-bracket mounting screws and nuts. Disconnect 2 electrical connectors and remove BCM. To install BCM, reverse removal procedure.
- Remove BCM as previously described. Remove PROM access over. Note position of PROM before removal.
- Grasp narrow ends of PROM with PROM remover, included with replacement PROM. (Scheme 3) Gently rock carrier from end to end while applying firm upward force until PROM is removed. Remove PROM from carrier.
Installation
- Place new PROM in carrier upside-down on flat surface (pins facing up). Using a narrow blunt tool, press the PROM body down on both sides of retainer bar so top of the PROM is flush with top of the carrier.
- Position PROM carrier squarely over PROM socket in BCM. Firmly press down on top of carrier. Alternately pressing down on either end of carrier will securely seat PROM. Install PROM access cover. Install BCM in vehicle.
- Perform PROM functional check. Turn ignition on. If the following conditions result, check PROM for proper orientation, bent or broken pins, and complete insertion. Climate Control Panel displays "-151" and no key response. Fuel Data Center (if applicable) is blank and no key response. A/C compressor is disabled. Heater Vent-Air Conditioning (HVAC) in defrost mode with blower on high. No BCM-to-ECM data communication. Vacuum fluorescent display dimming, parking lights on, commanded to full brightness.
- If not fully seated, remove access cover and press firmly on carrier. If pins are bent, remove PROM, straighten pins and reinstall. If pins break or crack during straightening, replace PROM. If PROM was installed backward, it must be replaced.
Note. When the CCP is displaying a prom error "-151" the diagnostic mode may not be entered.
Removing & Referencing Replacement PROM. Scheme 3
Disconnect negative battery cable. Remove center instrument panel trim plate. Remove mounting screws and pull panel/center out of instrument panel. Disconnect electrical connector. To install, reverse removal procedure.
THROTTLE POSITION SENSOR (TPS)
Note. DO NOT remove TPS unless all diagnosis confirms that TPS requires adjustment or repair.
Remove air cleaner and disconnect TPS electrical connector. Remove 2 TPS mounting screws, lock washers and retainers. Remove sensor from throttle body, noting location of TPS pick-up lever in relation to tang on throttle shaft lever.
- Position TPS over throttle shaft with TPS pick-up lever and throttle shaft lever tang in position as noted during removal. The pick-up lever is located above tang on throttle actuator lever.
- Install retainers, attaching screws, and lockwashers. Tighten screws enough that sensor is not loose, but can still move. DO NOT use thread locking compound on TPS attaching screws. Install electrical connector and adjust TPS. (Scheme 4)
Cadillac DFI Throttle Body Assembly. Scheme 4
Remove air cleaner and disconnect harness connector from ISC. Remove 2 mounting screws and ISC. To install, position ISC on throttle body, install mounting screws and adjust. (Scheme 5)
Note. DO NOT attempt to disassemble ISC motor. Always remove ISC before cleaning throttle body as immersion in cleaner will damage unit.
On DeVille and Fleetwood, sensor is located at right rear of engine compartment. On Eldorado and Seville, sensor is located on engine cowl lip above and behind air cleaner assembly. Disconnect MAP vacuum hose and electrical connector. Remove screws securing MAP sensor and remove sensor. To install, reverse removal procedure.
Remove instrument panel lower cover. Remove glove box liner. Disconnect BARO sensor electrical connector. Working through glove box opening, remove mounting bracket screw, then remove BARO sensor-to-mounting bracket and ground strap screws. Remove sensor. Reverse procedure to install.
Drain radiator until coolant level is below sensor level. Disconnect harness connector from sensor. Remove sensor from block. To install, first coat threads of sensor with non-hardening sealer. Install sensor in block. Reconnect harness connector. Refill radiator.
Disconnect negative battery cable. Locate oxygen sensor in exhaust manifold. Trace sensor wires to connector and disconnect. Using a box end wrench, remove oxygen sensor from manifold. Reverse procedure to install sensor. If original sensor is to be reused, it must be coated with anti-seize compound.
Remove air cleaner assembly. Locate sensor in intake manifold. Disconnect electrical connector and remove sensor. Apply non-hardening sealer to sensor. Reverse removal procedure to install.
