B3875
DTC B3875
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category
DTC Descriptor
DTC B3875 00
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Wiper High Speed Relay Circuit
Diagnostic Fault Information
Circuit/System Description
The body control module (BCM) monitors the windshield wiper speed 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 windshield wiper speed relay control circuit to the coil side of the relay, energizing the windshield wiper speed 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 windshield wiper speed relay control circuit.
Action Taken When the DTC Sets
The BCM will not activate the output.
Conditions for Clearing the DTC
* A current 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 Electrical Diagrams
Connector End View Reference
Component Connector End Views Fuel Pump and Level Sensor Assembly
Description and Operation
Wiper/Washer System Description and Operation Description and Operation
Electrical Information Reference
* Circuit Testing Circuit Testing
* Connector Repairs Connector Repairs
* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs Wiring Repairs
Scan Tool Reference
Control Module References Control Module References for scan tool information
Circuit/System Testing
1. Ignition OFF, remove the KR12C windshield wiper speed control relay.
2. Ignition ON, verify a test lamp illuminates between B+ circuit terminal 85 and ground.
• If the test lamp does not illuminate and the circuit fuse is good, test or replace the X50A underhood fuse block.
3. Connect a test lamp between B+ circuit terminal 85 and the control circuit terminal 86.
4. 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 K9 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 K9 BCM.
5. If all circuits test normal, replace the KR12C windshield wiper speed control relay.
Component Testing
1. Ignition OFF, disconnect the KR12C windshield wiper speed control relay.
2. Test for 60-200 ohms between terminals 85 and 86.
• If the resistance is not within the specified range, replace the 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 relay.
4. Test for less than 2 ohms between terminals 30 and 87A.
• If greater than the specified range, replace the relay.
5. Install a 10 A fused jumper wire between relay terminal 85 and B+. 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 relay.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the repair.
* Relay Replacement (Within an Electrical Center) Relay Replacement (Within an Electrical Center)Relay Replacement (Attached to Wire Harness) Relay Replacement (Attached to Wire Harness)
* Control Module References Control Module References for BCM replacement, programming and setup