B3875

DTC B3875

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) provides an overview of each diagnostic category



DTC Descriptor
DTC B3875 00
- Wiper High Speed Relay Circuit




Diagnostic Fault Information






Circuit/System Description

The Body Control Module (BCM) monitors the WIPER HIGH relay control circuit only when wiper high speed mode is active. When the wiper high speed mode is requested, the BCM responds by applying a ground through the WIPER HIGH relay control circuit to the coil side of the relay, energizing the WIPER HIGH relay and applying voltage to the wiper motors high speed circuit.


Conditions for Running the DTC

The BCM output is actively being requested.


Conditions for Setting the DTC

The BCM detects a short to voltage in the WIPER HIGH relay control circuit.


Action Taken When the DTC Sets

The BCM will not activate the output.


Conditions for Clearing the DTC

* A currect DTC will clear when the condition for setting the fault is no longer present.
* A history DTC will clear after 100 consecutive ignition cycles without a fault present.



Reference Information
Schematic Reference

Wiper/Washer Schematics ([1][2]Electrical Diagrams)
Connector End View Reference

Component Connector End Views (Connector Views)
Description and Operation

Wiper/Washer System Description and Operation (Description and Operation)


Electrical Information Reference
* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)


Scan Tool Reference

Control Module References (Programming and Relearning) for scan tool information


Circuit/System Verification

1. Ignition ON, Wiper switch in the HIGH position, verify the scan tool Windshield Wiper Switch parameter is HIGH.
2. Ignition ON, Wiper switch in the HIGH position, verify the scan tool Wiper High Speed Relay Command parameter is ON.
3. Ignition ON, Wiper switch in the HIGH position, verify the scan tool Wiper High Speed Switch parameter is Active.



Circuit/System Testing

1. Ignition OFF, remove the Wiper High relay .
2. Connect a test lamp between B+ circuit terminal 85 and the control circuit terminal 86.
3. Command the Wiper High Speed relay ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.

• If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the BCM.
• If the test lamp is always OFF, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM.

4. If all circuits test normal, replace the WIPER HIGH relay.



Component Testing

1. Ignition OFF, disconnect the WIPER HIGH relay.
2. Test for 60-200 ohms between terminals 85 and 86.

• If the resistance is not within the specified range, replace the WIPER HIGH relay.

3. Test for infinite resistance between the following terminals:

* 30 and 86
* 30 and 87
* 30 and 85
* 85 and 87


• If not the specified value, replace the WIPER HIGH relay.

4. Test for less than 2 ohms between terminals 30 and 87A.

• If greater than the specified range, replace the WIPER HIGH relay.

5. Install a 10A fused jumper wire between relay terminal 85 and 12 volts. Install a jumper wire between relay terminal 86 and ground. Test for less than 2 ohms between terminals 30 and 87.

• If greater than the specified range, replace the Wiper High relay.




Repair Instructions

Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.

* Relay Replacement (Attached to Wire Harness) (Relay Replacement (Attached to Wire Harness))Relay Replacement (Within an Electrical Center) (Relay Replacement (Within an Electrical Center))
* Control Module References (Programming and Relearning) for BCM replacement, setup, and programming