PCM Controlled Warning Lamps Diagnosis - Tachometer

PCM Controlled Warning Lamps Diagnosis Tach Output Circuit:

Engine Controls (DLC, Instrument Panel, Engine Compartment Fuse Center):

Diagnostic Aids

For diagnosis of the instrument panel, perform the System Check in the Instrument Panel Cluster (IPC) Microprocessor.

Check for the following conditions:

^ Poor connection at PCM. Inspect harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and poor terminal to wire connection.

^ Damaged harness. Inspect the wiring harness for damage.


Test Description

An example test description follows:

8. This vehicle is equipped with a PCM which utilizes an Electrically Erasable Programmable Read Only Memory (EEPROM). When the PCM is replaced, the new PCM must be programmed. Refer to PCM replacement and programming procedures in Powertrain Control Module. Engine Control Module