Diagnostic Aids
Perform this test when instructed during QUICK TEST or other test step. This test is only intended to diagnose the following:
- Harness circuits FP and PWR.
- Fuel pump relay.
- Faulty PCM.
NOTE:
If scan tool DIAGNOSTIC DATA LINK menu option is not functional, start testing at step 3).
CIRCUIT PIN IDENTIFICATION
| Circuit | PCM Pin No. | Wire Color |
|---|---|---|
| FPR | 11 | Blue/Red |
- 1) Check Fuel Pump PID
Turn ignition off. Connect NGS scan tool to fuse panel DLC. Turn ignition on. Access FPR PID. Crank engine. If FPR PID indicates OFF, go to step 10). If PUMP PID indicates ON during cranking, fuel pump relay is functioning properly at this time. Go to TEST Z for intermittent testing procedure. If engine will not start, go to next step. - 2) Check Relay Operation
Turn ignition on. Connect NGS scan tool to fuse panel DLC. Enter active command mode. Access FPR PID. Activate fuel pump. Listen for fuel pump relay to click when activated by NGS. If relay clicks during SIMULATION TEST, go to TEST HC for cause of no fuel pressure. Repeat QUICK TEST . If relay does not click, go to next step. - 3) Check Power To Relay
Turn ignition off. Disconnect fuel pump relay. Turn ignition on. Measure voltage between PWR circuit at fuel pump relay (Black/Red wire) and ground. See Fig 1. If voltage is greater than 10 volts, go to next step. If voltage is 10 volts or less, repair power circuit. See appropriate wiring diagram in WIRING DIAGRAMS article. - 4) Check FPR Circuit For Opens
Turn ignition off. Disconnect PCM. Remove fuel pump relay. Measure resistance of FPR circuit (Blue/Red wire) between PCM harness connector terminal No. 11 and fuel pump relay connector. See Fig 1. See CIRCUIT PIN IDENTIFICATION table. If resistance is less than 5 ohms, go to next step. If resistance is greater than 5 ohms, repair Blue/Red wire. Restore all electrical connections and repeat QUICK TEST . - 5) Check FPR Circuit For Short
Turn ignition off. Disconnect fuel pump relay. Measure resistance of FPR circuit (Blue/Red wire) between PCM connector and ground. See Fig 1. If resistance is greater than 10 k/ohms, replace fuel pump relay. Restore all electrical connections and repeat QUICK TEST . If resistance is less than 10 k/ohms, repair short to ground in FPR circuit (Blue/Red wire). Restore all electrical connections and repeat QUICK TEST.NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 5) to step 10). No test procedures have been omitted. - 10) Check Fuel Pump Operation
Turn ignition off. Inspect fuel pump relay vehicle harness connector for corrosion or poor connection. Repair if necessary. Turn ignition on. Fuel pump relay should click and click again 6 seconds later. If relay does not operate as specified, go to step 3). If relay operates as specified, fault is intermittent. Go TEST Z for intermittent diagnostic procedure.