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 B3876 5A: Front Wiper Park Switch Signal not Plausible

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

Park signal

B3876 5A

B3876 A5

B3876 A5

--

Wiper motor Ground

--

1

--

--

1. Wipers will not park.

Circuit/System Description

The windshield wiper park signal is an input to the Underhood Electrical Center (UEC) and a input to the rainsensor . It is a ‘ground’ signal when the wiper is in park position and ‘open’ when the wiper is in a wipe cycle. To indicate the reaching of the park position, the UEC sends the signal Windshield Wiper Park Position Active to the rainsensor, otherwise Inactive. The UEC also send Windshield Wiper Park Position Active to the CAN bus. The timing depends on the CAN bus .

Conditions for Running the DTC

    • Battery voltage must be between 9-16 volts.
    • Ignition switch in any power mode.

Conditions for Setting the DTC

    • Active wiper and no park signal for 20 seconds.
    • Active wiper and no release of wiper park signal for 20 seconds.

Actions Taken When the DTC Sets

If the Wiper is in a Wipe Cycle and the Park Position Signal does not become active or inactive within a programed time out default the Wiper goes into the Error Mode. In the Error Mode, the UEC drives the Wiper in the corresponding speed (Low or High) until the Steering Wheel Module sends Windshield Wiper Switch Activation = Off. Then the Wiper will be stopped immediately, regardless of the position on the windshield. It is possible to drive the wiper into any position with activation of Pulse/Mist.

Conditions for Clearing the DTC

    • The condition responsible for setting the DTC no longer exists.
    • A history DTC will clear once 100 malfunction-free ignition cycles have occurred.

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 Testing

  1. Ignition OFF, install scan tool.
  2. Disconnect wiring harness at wiper motor.
  3. Ignition ON.
  4. With scan tool monitor the wiper motor Park switch status should display as INACTIVE
  5. If not the specified value, test the signal circuit for a short to ground. If the circuit tests normal, replace the UEC.
  6. Connect a fused jumper wire between terminal 3 and ground at the wiper motor harness connector. Park switch status should display ACTIVE.
  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 UEC.
  8. Ignition OFF, measure resistance between wiper motor harness terminal  4 and Ground. Verify resistance is less than 0.3 Ohm .
  9. If not the specified value, test the ground circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the wiper motor.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Windshield Wiper System Module Replacement
    •  Control Module References for REC replacement, setup, and programming