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XB148 - Power to Pump Circuit: Intermittent Short to Ground



- Key "OFF".

- Disconnect Powertrain Control Module (PCM), Variable Control Relay Module (VCRM) and fuel pump. Inspect each connector for damaged or pushed out pins, corrosion, loose wires, etc. Service as necessary.

- Install breakout box. Leave the PCM, VCRM and fuel pump disconnected.

- Connect a test lamp between test pin 1 (KAPWR) and test pin 8 (FPM).

- Observe test lamp for an indication of a fault while performing the following (the light will turn on when a fault is detected, indicating a short to ground):

- Shake, wiggle, bend the power-to-pump circuit from the VCRM to the fuel pump, PCM and High Speed Fuel Pump (HFP) relay.

- Lightly tap on the Inertia Fuel Shutoff Switch and HFP relay (to simulate road shock).

- Is a fault indicated?

Yes -- Isolate fault and service as necessary. Remove breakout box. Reconnect all components. Start engine, wait 5 seconds. Key "OFF". Rerun quick test. Quick Test Appendix (Detailed Testing Instructions)

No -- Unable to isolate fault at this time. Reconnect all components. For further diagnosis using the EEC-IV Monitor Box or Scan Tool, go to Normal Scan Data Values. For further diagnosis of this, or any other symptom, return to Diagnostic Routines. Symptom Related Diagnostic Procedures