Chevrolet Trax: Rain sensor malfunction

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 Descriptors

DTC B370A

Rain Sensor

For symptom byte information, refer to Symptom Byte List .

Diagnostic Fault Information

Circuit/System Description

B+ and ground is supplied at all times to the rain sensor. The rain sensor communicates with the body control module (BCM) via serial data. When the ignition is in the ON or ACCESSORY position and the windshield wiper/washer switch is in the intermittent delay position, the BCM monitors the rain sensor to determine the rain build up on the windshield. As rain builds up on the windshield, the BCM will command the wipers to activate. The sensitivity of the wiper frequency is controlled by the intermittent delay of the windshield wiper/washer switch. As the sensitivity is increased, the BCM will command more frequent wiper activation based on rain build up on the windshield.

Reference Information

Schematic Reference

Wiper/Washer Schematics (Encore), Wiper/Washer Schematics (Trax)

Connector End View Reference

WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX - ENCORE WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX - TRAX

Description and Operation

Wiper/Washer System Description and Operation

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

1. Ignition ON.
2. Verify DTC B370A is not set.

• If DTC B370A is set

Refer to DTC B370A.

• If DTC B370A is not set

3. Verify DTC U151A is not set.

• If DTC U151A is set

Please Refer to DTC U1500-U15FF .

• If DTC U151A is not set

4. Verify the windshield wipers operate at low speed when the S82 Windshield Wiper/Washer Switch is in the LO position.

• If the windshield wipers are not operating at low speed

Refer to Windshield Wiper System Malfunction.

• If the windshield wipers are operating at low speed

5. Place the S82 Windshield Wiper/Washer Switch in the intermittent delay setting and spray the outside of the windshield in the area of the B117 Rain Sensor with a water bottle. It may be necessary to increase the sensitivity of the intermittent delay to achieve windshield wiper operation.
6. Verify the windshield wipers operate at low speed.

• If the wipers are not operating at low speed

Test or replace the B117 Rain Sensor.

• If the wipers are operating at low speed

7. All OK.

Circuit/System Testing

• Ignition OFF, all vehicle systems OFF, disconnect the harness connector at the B117 Rain Sensor. It may take up to 2 min for all vehicle systems to power down.
• Test for less than 10 ohms between the ground circuit terminal 3 and ground.

If 10 ohms or greater

1. Ignition OFF.
2. Test for less than 2 ohms in the ground circuit end to end.

• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, repair the open/high resistance in the ground connection.
• If less than 10 ohms

3. Ignition ON.
4. Verify a test lamp illuminates between the B+ circuit terminal 1 and ground.

If the test lamp does not illuminate and the circuit fuse is good

1. Ignition OFF, remove the test lamp.
2. Test for less than 2 ohms in the B+ circuit end to end.

• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, verify the fuse is not open and there is voltage at the fuse.
• If the test lamp does not illuminate and the circuit fuse is open

1. Ignition OFF, remove the test lamp.
2. Test for infinite resistance between the B+ circuit and ground.

• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance, replace the B117 Rain Sensor.
• If the test lamp illuminates

5. Test for 4.0-12.0 V between the serial data circuit terminal 2 and ground.

• If less than 4.0 V

1. Ignition OFF, disconnect the harness connector at the K9 Body Control Module.
2. Test for infinite resistance between the serial data circuit and ground.

• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance

3. Test for less than 2 ohms in the serial data circuit end to end.

• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, replace the K9 Body Control Module.
• If greater than 12.0 V

1. Ignition OFF, disconnect the harness connector at the K9 Body Control Module, ignition ON.
2. Test for less than 1 V between the serial data circuit and ground.

• If 1 V or greater, repair the short to voltage on the circuit.
• If less than 1 V, replace the K9 Body Control Module.
• If between 4.0-12.0 V

6. Test or replace the B117 Rain Sensor.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

• Windshield Outside Moisture Sensor Replacement
• Control Module References for body control module replacement, programming, and setup.

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