Engine Control Module: Service and Repair

(Figure 1) Servicing the PTM:

Control Module Mounting:

(Figure 3) PROM (MEM-CAL) Unit Installation:

POWERTRAIN CONTROL MODULE
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 replacement control module as the replacement control module will not contain a PROM (MEM-CAL).

CAUTIONS:
^ The ignition must be "OFF," when disconnecting or reconnecting the control module connector, to prevent internal damage to the PCM.
^ To prevent possible Electrostatic Discharge to the PCM, do NOT touch the connector pins or soldered components on the circuit boards.

NOTE: 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.


REMOVAL
1. Disconnect the negative battery terminal.
2. Remove passenger kick panel.
3. Remove control module retainer and control module.
4. Disconnect control module harness connectors.
5. Remove brackets and modules as equipped.
6. Remove the new PCM from its packaging and check the service number to make sure it is the same as the defective PCM.
7. Remove access cover.

8. Remove PROM (MEM-CAL) as follows:
The replacement PCM is supplied without a PROM (MEM-CAL). Care should be taken when removing the PROM from the defective PCM for use in the replacement PCM. Using two fingers, push both retaining clips back away from the PROM (MEM-CAL). At the same time, grasp it at both ends and lift it up out of the socket (Figure 1). Do NOT remove the cover of the PROM (MEM-CAL). Use of unapproved PROM (MEM-CAL) removal methods may cause damage to the PROM (MEM-CAL) or socket.

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.

Inspection
Inspect for alignment notches of the PROM (MEM-CAL) and carefully set it aside. Do not open the PROM (MEM-CAL).

INSTALLATION
1. Install the PROM (MEM-CAL) in PROM (MEM-CAL) socket as follows:
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.

2. Install the access cover in the new control module.
3. Install mounting brackets and module(s) as equipped.
4. Connect control module harness connectors.
5. Install control module and retainer.
6. Install passenger kick panel.
7. Connect the negative battery terminal.
8. Perform functional check below.

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.
^ If not fully seated, press firmly on the ends of the PROM (MEM-CAL).
^ If it is necessary to remove the PROM (MEM-CAL), follow the previous removal instructions.