Workshop Manuals Factory service & repair Vauxhall
Vauxhall Astra J05 · Body Systems
05 · Body & interior

DTC B370B

Make
Vauxhall
Model
Astra J
Section
Wipers and Washers › Other Information › DTC B370B
Body SystemsDTC B370B

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. Rear Wiper Inoperative.

2. Rear Wiper Always ON.
 

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 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


Schematic Reference

Wiper/Washer Schematics


Connector End View Reference

Component Connector End Views


Description and Operation

Wiper/Washer System Description and Operation


Electrical Information Reference


Scan Tool Reference

Control Module References for scan tool information

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector X4 at the K9 body control module.
2. Ignition ON, install a test lamp between the control circuit terminal 8 at the K9 body control module connector X4 and ground.
3. Verify the test lamp does not illuminate.
⇒ If the test lamp does illuminate, test the control circuit for a short to voltage.
4. Ignition OFF, disconnect the harness connector X2 at the X50A underhood fuse block.
5. Test for less than 5 Ω between the control circuit terminal 34 at the X50A underhood fuse block connector X2 and the control circuit terminal 8 at the K9 body control module connector X4.
⇒ 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.
6. If all circuits test normal, test or replace the X50A underhood fuse block.

Component Testing

Output Control Test

Ignition ON, Command the Rear Wiper Command On and OFF with a scan tool. 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 underhood fuse block. 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

1. Ignition OFF, disconnect the harness connector X4 at the K9 body control module.
2. Test for 60-200 Ω between terminal 8 and ground.
⇒ If the resistance is not within the specified range, test the control circuit for a short to ground, short to voltage or an open/high resistance.
⇒ If all circuits test normal, test or replace the X50A underhood fuse block.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

•  Control Module References for BCM replacement, programming and setup

Parts & tools for this job For Vauxhall Astra

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