Service Information

Orlando

DTC B370B

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 B370B 02: Rear Wiper Function Control Circuit Short to Ground

Diagnostic Fault Information

Circuit	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performance
Rear Wiper Switch Signal	2	1	1	--
Rear Window Wiper Control	1	1	2	--
Rear Window Wiper Relay Control	B370B 02	1	2	--
Rear Window Wiper Ground	--	1	1	--
1. Washer Inoperative. 2. Washer Always ON.

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 or an open/high resistance 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

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 Verification

Operate the rear wiper by using the S82 Windscreen Wiper/Washer Switch in the continuous and the intermittent position. Verify the M45 Rear Wiper Motor activates.

Circuit/System Testing

Ignition OFF, disconnect the harness connector X2 at the X50A Fuse Block - Underhood.
Disconnect the harness connector X4 at the K9 Body Control Module.
Test for less than 5 Ω between the control circuit terminal 11 X2 at the X50A Fuse Block - Underhood and the control circuit terminal 10 X4 at the K9 Body Control Module.

⇒	If the value is greater than 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.

If all circuits test normal, test or replace the X50A Fuse Block - Underhood.

Component Testing

Output Control Test

Ignition ON, Command the Rear Wiper Relay Command On and OFF with the rear wiper switch. Observe the KR7 Rear Wiper Relay clicks and the M45 Rear Wiper Motor runs.

⇒	If the KR7 Rear Wiper Relay does not work, replace the X50A Fuse Block - Underbonnet.

⇒	If the KR7 Rear 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.

Relay Test

Ignition OFF, connect the harness connector X2 at the X50A Fuse Block - Underhood.
Disconnect the harness connector X4 at the K9 Body Control Module.
Test for 60-200 Ω between terminals 10 X4 and ground.

⇒	If the resistance is not within the specified range, test the control circuit for a short to ground or an open/high resistance.

⇒	If all circuits test normal, test or replace the X50A Fuse Block - Underhood.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

•	Control Module References for BCM replacement, setup, and programming

•	Relay Replacement : Attached to Wire Harness

•	Rear Window Wiper Motor Replacement