Powertrain Control Module - Service Precaution

NO: 18-21-98

GROUP: Vehicle Performance

DATE: Jun. 5, 1998

SUBJECT:

Powertrain Control
Module (PCM)
Service Caution

MODELS:

1996 - 1998 (AB) Ram Van
1996 - 1998 (AN) Dakota
1996 - 1998 (BR/BE) Ram Truck
1998 (DN) Durango
1997 - 1998 (TJ) Wrangler
1996-1998 (XJ) Cherokee
1996-1998 (ZJ) Grand Cherokee
1996 - 1998 (ZG) Grand Cherokee (European Market)

DISCUSSION:

Whenever any connector on the PCM is disconnected, the ignition switch must be in the "OFF" position for a minimum of 5 seconds before connector removal.

It has been found under certain key "ON" or momentary key "OFF" conditions, when the black connector is unplugged, the PCM may attempt to write information to the EEPROM processor within the PCM. Sometimes this inadvertent write will set the target charging voltage to 0 (zero) volts. The result will prevent the charging system from charging the battery.

If this occurs, the only correction is PCM replacement.

POLICY: Information Only