GM Service Manual Online
For 1990-2009 cars only

Diagnostic Instructions

    • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
    • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
    •  Diagnostic Procedure Instructions provides an overview of each diagnostic category.

Circuit/System Description

If there is water in the fuel system, the water in fuel sensor switch will close and produce a low voltage on the signal circuit. When the instrument panel cluster (IPC) detects a low signal from the water in fuel sensor the IPC will then illuminate the WATER IN FUEL indicator in the driver information center (DIC).

Reference Information

Schematic Reference

    •  Instrument Cluster Schematics
    •  Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Instrument Cluster Description and Operation

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

Scan Tool Reference

Control Module References

Circuit/System Testing

  1. Ignition OFF, disconnect the harness connector at the water in fuel sensor.
  2. Ignition OFF, test for less than 1.0 ohm of resistance between the ground circuit terminal B and ground.
  3. If greater than 1.0 ohm, test the ground circuit for an open/high resistance.
  4. Install a 3-amp fused jumper wire between the signal circuit terminal A and ground. Verify the scan tool Water In Fuel Sensor parameter is Water.
  5. If not Water, test the signal circuit of the water in fuel sensor for a short to voltage or an open/high resistance. If the circuit tests normal, replace the DIC.
  6. If all circuits test normal, test or replace the water in fuel sensor

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Water in Fuel Indicator Sensor Replacement
    •  Control Module References for the IPC and DIC replacement, setup, and programming