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.

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

Washer Fluid Level Sensor Signal

2

1

1

--

Washer Fluid Level Sensor Ground

--

1

1

--

1. Low Washer Fluid Indicator Inoperative

2. Low Washer Indicator Always On

Circuit/System Description

The BCM monitors the washer fluid level sensor via the washer fluid level sensor signal circuit. With the switch closed, the signal circuit is pulled to ground indicating low fluid level. When low fluid level is indicated, the BCM sends a serial data message to the IPC to illuminate the low washer fluid indicator.

Reference Information

Schematic Reference

Wiper/Washer Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Wiper/Washer System 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 for scan tool information

Circuit/System Verification

  1. Verify the windshield washer fluid level is above the minimum level.
  2. If not above the minimum level, fill the reservoir and inspect for leaks.
  3. Verify the IPC Low Washer Fluid message is not on.
  4. Verify that there are no serial data communication DTC's. Refer to Symptoms - Data Communications.

Circuit/System Testing

  1. Ignition OFF, disconnect the harness connector at the washer fluid level sensor.
  2. Test for less than 1 ohm between the ground circuit terminal A and ground.
  3. If greater than the specified range, test the ground circuit for an open/high resistance.
  4. Ignition ON, verify the Low Washer Fluid Level message is OFF.
  5. If not the specified value, test the signal circuit terminal B for a short to ground. If the circuit tests normal, replace the BCM.
  6. Install a 3A fused jumper wire between the signal circuit terminal B and the ground circuit terminal A. Verify the Low Washer Fluid message is ON.
  7. If not the specified value, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM.
  8. If all the circuits test normal, test or replace the washer fluid level sensor.

Component Testing

  1. Ignition OFF, disconnect the harness connector at the washer fluid level sensor.
  2. Washer fluid level switch open, test for infinite resistance between the signal terminal B and the ground terminal A.
  3. If not the specified value, replace the washer fluid level sensor.
  4. Washer fluid level switch closed, test for less than 2 ohms between the signal terminal B and the ground terminal A.
  5. If not within the specified range, replace the washer fluid level sensor.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Windshield Washer Solvent Level Switch Replacement
    •  Control Module References for IPC replacement, setup, and programming