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.

DTC Descriptor

DTC B371B 02: Washer Fluid Heater Enable Circuit Short to Ground

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

Windshield Washer Switch Signal

2

1

1

--

Heated Washer Nozzle Module B+

1

1

--

--

Washer Fluid Heater Enable

B371B 02

1

1

--

Heated Washer Nozzle Module Ground

--

1

1

--

1. Heated Washer Inoperative

2. Heated Washer Always ON

Circuit/System Description

The heated washer nozzle module monitors the temperature of the washer fluid, heats the washer fluid when requested, and signals the Body Control Module (BCM) at the appropriate time to activate the washer system. It also provides a low side drive communication output to the display system in order to provide the customer both button activation feedback and system status feedback.

Conditions for Running the DTC

    • Ignition ON.
    • The system voltage is between 9 V and 16 V.

Conditions for Setting the DTC

A short to ground or an open/high resistance is detected in the washer fluid heater enable circuit.

Action Taken When the DTC Sets

Heated wash operation is suspended.

Conditions for Clearing the DTC

A current DTC clears when the diagnostic runs and passes.

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 diagnostic tester information.

Circuit/System Verification

Command the heated washer ON by using the S78 Turn Signal/Multifunction Switch. Verify the K 80 Heated Washer Nozzle Module activates.

Circuit/System Testing

  1. Ignition OFF, disconnect the X2 harness connector at the K 80 Heated Washer Nozzle Module.
  2. Test for more than 500 kΩ between the enable circuit X2 terminal 6 and ground.
  3. If less than the specified value, test the enable circuit for an short to ground
    If all circuits test normal, test or replace the K9 Body Control Module (BCM).

Component Testing

Output Control Test

  1. Ignition ON, command the K80 Heated Washer Nozzle Module ON and OFF with a scan tool. Observe the K80 Heated Washer Nozzle Module activates.
  2. If the K80 Heated Washer Nozzle Module does not activate, replace the K80 Heated Washer Nozzle Module.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Control Module References for BCM replacement, setup, and programming.
    • LInk X for Heated Washer Nozzle Module replacement.