DTC 54

DIAGNOSTIC CHART





WIRING DIAGRAM

INSPECTION PROCEDURE

Circuit Description:
When the ignition switch is turned "ON", the Engine Control Module (ECM) will activate the FP relay and run the in-tank fuel pump. The fuel pump will operate as long as the engine is cranking or running, and the ECM is receiving ignition reference pulses.
If there are no reference pulses, the ECM will shut "OFF" the fuel pump within 2 seconds after key "ON".
Should the FP relay, or the 12 volt relay drive from the ECM fail, the FP will be run through an oil pressure switch which activates the back up relay circuit.

Diagnostic Aids:
An inoperative FP relay can result in long cranking times, particularly if the engine is cold or engine oil pressure is low. The extended crank period is caused by the time necessary for oil pressure to build enough to close the oil pressure switch and turn "ON" the FP.
Intermittent problems may be caused by:
- Poor wiring connections
- Corrosion
- All connections should be checked visually