Powertrain Control Module (PCM) Replacement
PCM Mounting:
Replacement of the Powertrain Control Module (PCM) consists of a service controller, without a PROM (MEM-CAL).
If the diagnostic procedures require the PCM to be replaced, the PCM, PROM (MEM-CAL) should be checked for the correct part number. If they are correct, remove the PROM (MEM-CAL), and install them in the control module. The control module will not contain a PROM (MEM-CAL).
When replacing a production PCM with a control module, transfer the broadcast code and production PCM part number to the control module label. Do not record information on the access cover.
CAUTION:
- The ignition must be "OFF," and disconnect negative battery cable when disconnecting or reconnecting the PCM connector, to prevent internal damage to the PCM.
- To prevent possible Electrostatic Discharge damage to the PCM, Do Not touch the connector pins or soldered components on the circuit board.
REMOVE OR DISCONNECT
1. Negative battery cable.
2. Glove box.
3. PCM harness connectors.
4. PCM from tray.
5. Mounting brackets and modules if equipped.
6. Access cover PROM (MEM-CAL). Refer to PROM (MEM-CAL) service.
INSTALL OR CONNECT
1. PROM (MEM-CAL) access cover in new PCM.
2. Mounting brackets and modules if equipped.
3. PCM into tray until clips lock.
4. PCM harness connectors.
5. Glove box.
6. Negative battery cable.
7. Perform functional check.
Prom (MEM-Cal) Unit Installation:
PCM Top Cover:
Retaining Clips:
MEM-CAL REPLACEMENT
REMOVE OR DISCONNECT
1. Powertrain Control Module (PCM) access cover.
NOTE: DO NOT remove any of the other screws.
2. PCM access cover.
CAUTION: Replacement Powertrain Control Module (PCM) is supplied without a Memory-Calibration unit Programmable Read Only Memory (PROM) (MEM-CAL) so care should be taken when removing the PROM (MEM-CAL) from the defective PCM as it will be reused in the new PCM.
3. Using two fingers, push both retaining clips back away from the PROM (MEM-CAL) at the same time. Grasp the PROM (MEM-CAL) at both ends and lift straight up out of the PROM (MEM-CAL) socket. Do not remove the cover of the PROM (MEM-CAL). Use of unapproved PROM (MEM-CAL) removal methods will cause damage to the PROM (MEM-CAL) or PROM (MEM-CAL) socket.
Inspect
For alignment notches of the PROM (MEM-CAL) and carefully set aside. Do not open the PROM (MEM-CAL).
4. New Powertrain Control Module (PCM) from its packaging and check the service number to make sure it is the same as the defective PCM.
5. Access cover.
INSTALL OR CONNECT
1. PROM (MEM-CAL) in PROM (MEM-CAL) socket.
Prom MEM-Cal Clips:
Inspect
Type of clips used on the PROM (MEM-CAL) sockets. There are two types of clips used on the PROM (MEM-CAL) sockets. A solid type is used on the early production models.
Prom MEM-Cal Clips Location:
NOTE:
- Press only on the ends of the PROM (MEM-CAL).
- Small notches in the PROM (MEM-CAL) must be aligned with the small notches in the PROM (MEM-CAL) socket.
Gently press down on the ends of the PROM (MEM-CAL) until the clips are against the side of the PROM (MEM-CAL). Press inward on the clips until they snap into place. Listen for the click.
CAUTION: Do not press on the ends of the PROM (MEM-CAL) until the clips snap into place because the controller circuit board and/or clips may be damaged.
Retaining Clips:
Inspect
Retaining clip have snapped into place.
INSTALL OR CONNECT
1. Access cover on PCM.
2. PCM to mounting bracket in correct location and perform On-Board Diagnostic (OBD) System Checks to confirm proper installation. Refer to System Diagnosis. Testing and Inspection
FUNCTIONAL CHECK
1. Turn ignition "ON."
2. Enter diagnostics.
A. DTC 12 should flash four times (if no other DTC(s) are present). This indicates the PROM (MEM-CAL) is installed properly, and the PCM is functioning.
B. If DTC 51 occurs, or if the MIL is "ON" constantly with no DTC(s), the PROM (MEM-CAL) is not fully seated or is defective.
C. If not fully seated, press firmly on the ends of the PROM (MEM-CAL).
D. If it is necessary to remove the PROM (MEM-CAL), follow the previous removal instructions.
CAUTION: To prevent possible Electrostatic Discharge damage to the PROM (MEM-CAL), Do Not touch the component leads, and Do Not remove integrated circuit from carrier.