Chevrolet Trax: DTC B356A: Vehicle direction warning switch circuit

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 B356A 02

Vehicle Direction Warning Switch Circuit Short to Ground

DTC B356A 05

Vehicle Direction Warning Switch Circuit Short to Voltage

Diagnostic Fault Information

Circuit/System Description

The lane departure warning feature is enabled and disabled through the lane departure switch located in the left steering wheel controls switch. When enabled, the frontview camera module will illuminate the indicator located in the switch. The forward collision alert distance is adjustable using the forward collision switch located in the center console. The setting is shown in the driver information center.

When the system is operating and can detect the lane markings, the frontview camera module will request via serial data communications that the instrument panel cluster illuminate the green lane departure ready-to-assist indicator. If the frontview camera module detects that the vehicle has crossed a lane marking without the turn signal being used, the module will request that the instrument cluster flash the yellow lane departure warning indicator. An audible warning will also sound three times when the yellow instrument cluster indicator is flashing.

Conditions for Running the DTC

Ignition ON.

Conditions for Setting the DTC

DTC B356A 02

The frontview camera module has detected a short to ground for more than 10 s.

DTC B356A 05

The frontview camera module has detected a short to voltage or an open/high resistance for more than 10 s.

Action Taken When the DTC Sets

• Lane departure and forward collision warning features are disabled.
• Service Front Camera is displayed on the driver information center.

Conditions for Clearing the DTC

• The condition responsible for setting the DTC no longer exists.
• A history DTC will clear once 100 consecutive malfunction-free ignition cycles have occurred

Diagnostic Aids

Manually pressing the lane departure warning switch or forward collision alert switch for approximately 10 s will cause this DTC to set.

Reference Information

Schematic Reference

Object Detection Schematics (Encore), Object Detection 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

Object Detection Description and Operation (Rearvision Camera, UVC), Object Detection Description and Operation (Rear Park Assist, UD7), Object Detection Description and Operation (Side Blind Zone Alert, UFT), Object Detection Description and Operation (Rear Cross Traffic Alert, UFG)

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 the scan tool Lane Departure Warning Switch Status parameter changes between Open and Closed while pressing and releasing the lane departure warning switch.

• If the parameter does not change

Refer to Circuit/System Testing.

• If the parameter changes

3. Verify the driver information center displays and adjusts forward collision alert setting while repeatedly pressing and releasing the forward collision switch. The setting should change cycle between far, medium, near, and off.

• If the display does not change

Refer to Circuit/System Testing.

• If the display changes

4. All OK.

Circuit/System Testing

1. Ignition OFF and all vehicle systems OFF, disconnect the harness connectors at the S48E Multifunction Switch - Center Console and S70L Steering Wheel Controls Switch - Left. It may take up to 2 min for all vehicle systems to power down.
2. Test for less than 10 ohms between the following ground circuit terminals and ground:

• S48E Multifunction Switch - Center Console terminal 9
• S70L Steering Wheel Controls Switch - Left terminal 7
• If 10 ohms or greater

1. 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 the scan tool Lane Departure Warning Switch Status parameter is Open.

• If not Open

1. Ignition OFF, disconnect the harness connector at the K109 Frontview Camera Module.
2. Test for infinite resistance between the S48E Multifunction Switch - Center Console signal circuit terminal 7 and ground.

• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance, replace the K109 Frontview Camera Module.
• If Open

5. Install a 3 A fused jumper wire between the S48E Multifunction Switch - Center Console signal circuit terminal 7 and ground.
6. Verify DTC B356A 02 sets in approximately 10 s.

• If DTC does not set

1. Ignition OFF, remove the jumper wire, disconnect the harness connector at the K109 Frontview Camera Module, ignition ON.
2. Test for less than 1 V between the signal circuit and ground.

• If 1 V or greater, repair the short to voltage on the circuit.
• If less than 1 V

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

• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, replace the K109 Frontview Camera Module.
• If DTC sets

7. Test or replace the S48E Multifunction Switch - Center Console or S70L Steering Wheel Controls Switch - Left.

Component Test

Forward Collision Alert Switch

1. Ignition OFF, disconnect the harness connector at the S70L Steering Wheel Controls Switch - Left.
2. Test for infinite resistance between the control circuit terminal 2 and ground circuit terminal 7.

• If less than infinite resistance

Replace the S70L Steering Wheel Controls Switch - Left.

• If infinite resistance

3. Test for 1.0k - 1.5k ohms between the control circuit terminal 2 and ground circuit terminal 7 while pressing forward collision alert switch.

• If not between 1.0k - 1.5k ohms

Replace the S70L Steering Wheel Controls Switch - Left.

• If between 1.0k - 1.5k ohms

4. All OK.

Lane Departure Warning Switch

1. Ignition OFF, disconnect the harness connector at the S48E Multifunction Switch - Center Console.
2. Test for infinite resistance between the control circuit terminal 7 and ground circuit terminal 9.

• If less than infinite resistance

Replace the S48E Multifunction Switch - Center Console.

• If infinite resistance

3. Test for 3.8k - 5.8k ohms between the control circuit terminal 7 and ground circuit terminal 9 while pressing the lane departure warning switch.

• If not between 3.8k - 5.8k ohms

Replace the S48E Multifunction Switch - Center Console.

• If between 3.8k - 5.8k ohms

4. All OK.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

• Accessory Switch Replacement (Encore) , Accessory Switch Replacement (Trax)
• Cruise Control Switch Replacement
• Control Module References for frontview camera module replacement, programming, and setup.

SYMPTOMS - OBJECT DETECTION

NOTE: The following steps must be completed before using the symptom tables:

1. Perform the Diagnostic System Check - Vehicle before using the Symptom List in order to verify that all of the following are true:

• There are no DTCs set.
• The control modules can communicate via the serial data link.

NOTE: The rear vision camera does not communicate on the serial data bus.

2. Review the system operation in order to familiarize yourself with the system functions. Refer to Object Detection Description and Operation (Rearvision Camera, UVC), Object Detection Description and Operation (Rear Park Assist, UD7), Object Detection Description and Operation (Side Blind Zone Alert, UFT), Object Detection Description and Operation (Rear Cross Traffic Alert, UFG).

Visual/Physical Inspection

• Inspect for aftermarket devices which may affect the operation of the system. Refer to Checking Aftermarket Accessories .
• Inspect the easily accessible or visible system components for obvious damage or conditions which may cause the symptom.
• Make sure the parking assist sensors located on the vehicle front and rear bumper are clear. Remove any snow, mud or ice that is blocking the sensors.

Intermittent

Faulty electrical connections or wiring may be the cause of intermittent conditions. Refer to Testing for Intermittent Conditions and Poor Connections .

Symptom List

• Lane Departure Warning System Malfunction
• Parking Assist System Malfunction
• Rear Vision Camera System Malfunction

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