Engine Control Module ECM

DTC 54 Chart:

DTC 54 Fuel Pump Circuit:

Circuit Description:
The status of the fuel pump CKT 120 is monitored by the ECM at terminal "B2" and is used to compensate fuel delivery based on system voltage. This signal is also used to store a DTC if the fuel pump relay is defective or fuel pump voltage is lost while the engine is running. There should be about 12 volts on CKT 120 for at least two seconds after the ignition is turned "ON," or any time reference pulses are being received by the ECM.

DTC 54 Will Set When: The voltage at terminal "B2" is less than two volts for one second since the last reference pulse was received. This DTC is designed to detect a faulty relay, causing extended crank time and the DTC will help the diagnosis of an engine that "Cranks But Will Not Run."

Action Taken (ECM will default to): The Malfunction Indicator Lamp (MIL) will illuminate.

DTC 54 Will Clear When: Conditions for fault are no longer present and Tech 1 "Clear DTCs" function is used or 50 ignition switch keycycles have passed with no further faults or ignition switch is turned "OFF" and ECM B fuse is removed for 10 seconds.

DTC Chart Test Description: Number(s) below refer to circled number(s) on the diagnostic chart.

1. Checks to see if DTC was set as result of a hard failure or intermittent condition.

2. Checks relay, relay power feed and ground circuits.

3. Checks ECM and oil pressure switch.

Diagnostic Aids:

^ Refer to DIAGNOSIS BY SYMPTOM/ INTERMITTENTS - Intermittent Malfunctions.