B3718

DTC B3715, B3716, B3717, B3718, or B3719

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 Descriptors
DTC B3717
- Front Wiper Relay Drive Circuit Low

DTC B3718
- Front Wiper Relay Drive Circuit High




Diagnostic Fault Information






Circuit/System Description

The body control module (BCM) controls and monitors the state of the ON/OFF wiper relay control circuit. When the windshield wiper switch is placed in to a low speed setting, a signal is applied to the BCM. The BCM then applies battery positive voltage to the coil side of the ON/OFF WPR relay through the relay control circuit. This energizes the relay, allowing battery positive voltage from the FRT/WPR fuse through the switched side of the ON/OFF WPR relay through the HI/LOW WPR relay and to the windshield wiper motor. Ground is applied at all times to the coil sides of the wiper relays and the windshield wiper motor from G105.


Conditions for Running the DTC

The battery voltage must be between 9-16 volts.


Conditions for Setting the DTC

B3713

When the BCM receives a front wiper switch on command and the on/off wiper relay control circuit is shorted to ground.

B3718

When the BCM receives a front wiper switch off command and the on/off wiper relay control circuit is shorted to voltage.


Action Taken When the DTC Sets

The front wipers will not operate or will remain always on.


Conditions for Clearing the DTC

* This DTC will clear on current status after the condition for setting the fault is corrected.
* 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 (Front) (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

Ignition ON, operate the front wiper switch between low and off and verify that the front wipers turn on and off.

If the front wipers do not turn on or remain always on perform the On/Off Wiper Relay Control Circuit Test.



Circuit/System Testing


On/Off Wipe Relay Control Circuit Test
1. Ignition OFF, disconnect the on/off wiper relay.
2. Verify that a test lamp illuminates when connected from battery voltage to the relay coil ground circuit terminal 86.

• If the test lamp does not illuminate test the ground circuit for an open/high resistance.

3. Connect a test lamp between the relay coil control circuit terminal 85 and the ground circuit terminal 86.
4. Ignition ON, operate the front wiper switch between low and off and verify that the test lamp turns on and off.

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

5. If all circuits test normal, test or replace the relay.



Repair Instructions

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


Control Module References (Programming and Relearning) for BCM replacement, setup, and programming