B370B
DTC B370B
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 B370B 02
- Rear Wiper Function Control Circuit Short to Ground
Diagnostic Fault Information
Circuit/System Description
The body control module (BCM) controls the single speed rear wiper motor by its active high output to the external rear wiper motor relay. When the BCM activates its output and applies battery to the coil of the relay, the relay energizes, allowing battery voltage from the fuse to be applied through the switched contacts of the rear wiper motor relay to the control input of the rear wiper motor. The motor then operates continuously at low speed.
Conditions for Running the DTC
* Ignition ON.
* The system voltage is between 9-16 V.
Conditions for Setting the DTC
A short to ground is detected in the rear window wiper control circuit.
Action Taken When the DTC Sets
Rear wiper 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 (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 (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 (Programming and Relearning) for diagnostic tester information.
Circuit/System Verification
Operate the rear wiper by using the S80 Window Wiper/Washer Switch in the continuous and the intermittent position. Verify the M45 Rear Wiper Motor activates.
Circuit/System Testing
1. Ignition OFF, disconnect the harness connector C at the X50A Fuse Block - Underhood.
2. Disconnect the harness connector X4 at the K9 Body Control Module.
3. Test for less than 5 ohm between the control circuit terminal 5 C at the X50A Fuse Block - Underhood and the control circuit terminal 10 X4 at the K9 Body Control Module.
• If the value is not within the specified range, test the control circuit for a short to voltage or an open/high resistance.
• If the circuit tests normal, test or replace the K9 Body Control Module.
4. Test for infinite resistance between the control circuit terminal 5 C at the X50A Fuse Block - Underhood and ground.
• If the value is not within the specified range, test the control circuit for a short to ground.
5. If all circuits test normal, test or replace the X50A Fuse Block - Underhood.
Component Testing
Relay Test
1. Ignition OFF, disconnect the harness connector B at the X50A Fuse Block - Underhood.
2. Test for 60-200 ohm between control circuit terminal 5 C and ground circuit terminal 5 B.
• If all circuits test normal, test or replace the X50A Fuse Block - Underhood.
Output Control Test
Connect all harness connectors, ignition ON, Command the Rear Wiper Relay Command On and OFF with a scan tool. Observe the KR7 Rear Window Wiper Relay clicks and the M45 Rear Wiper Motor runs.
If the KR7 Rear Window Wiper Relay does not work, replace the X50A Fuse Block - Underhood.
If the KR7 Rear Window Wiper Relay does work, but the M45 Rear Wiper Motor does not run, test the M45 Rear Wiper Motor ground and control circuit.
If all circuits test normal, replace the M45 Rear Wiper Motor.
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
* Relay Replacement (Attached to Wire Harness) (Relay Replacement (Attached to Wire Harness))Relay Replacement (Within an Electrical Center) (Relay Replacement (Within an Electrical Center))
* Rear Window Wiper Motor Replacement (Equinox) (Rear Window Wiper Motor Replacement)Rear Window Wiper Motor Replacement (Terrain) (Rear Window Wiper Motor Replacement)