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Backup Lamps Malfunction

Backup Lamps 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 has overviews of all diagnostic categories.


Diagnostic Fault Information

Circuit Short to Ground Open/High Resistance Short to Voltage Signal Performance
Reverse Gear Signal

2

1

1

C0010 5A

1. Reverse gear lamp inoperative

2. Reverse gear lamp always ON



Circuit/System Description

When the transmission is placed in reverse gear, the engine control module (ECM) sends a serial data message to the body control module (BCM). The message indicates that the gear selector is in the reverse position. The BCM applies battery voltage to the backup lamps. The backup lamps are permanently grounded. Once the driver moves the gear selector out of the reverse position, a message is sent by the ECM via serial data requesting the BCM to remove battery voltage from the backup lamp control circuit.

Reference Information

Schematic Reference

Exterior Lights Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Exterior Lighting Systems 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 information on diagnostic tools

Circuit/System Verification

Ignition ON, perform the Backup Lamps Relay Command test. The backup lamp should be ON/OFF.

Circuit/System Testing


1. Ignition OFF, disconnect the harness connector at the B16 Backup Lamp Switch.

2. Test for less than 5 Ω between the ground circuit harness connector terminal 2 and ground.

3. If greater than the specified range, test the ground circuit for an open/high resistance.

4. Disconnect the X1 or X2 harness connector at the K20 Engine Control Module.

5. Ignition ON, test for less than 0.3 V at the B16 Backup Lamp Switch signal circuit harness connector terminal 1 and ground.

6. If greater then the specified value, test the signal circuit for a short to voltage.

7. Ignition OFF, test for infinite resistance between the B16 Backup Lamp Switch signal circuit harness connector terminal 1 and ground.

8. If lower then the specified value, test the signal circuit for a short to ground.

9. Connect the harness connector at the B16 Backup Lamp Switch.

10. Reversing gear engaged, test for less than 5 Ω between the K20 Engine Control Module X1 or X2 harness connector terminal listed below and ground:

• X1 Terminal 34 with LBY

• X2 Terminal 75 with LBS

• X1 Terminal 18 with LDK or LBW

• X2 Terminal 82 with LLU

11. If greater then the specified value, test the signal circuit for an open circuit/high resistance. If the circuit test normal, test or replace the B16 Backup Lamp Switch.

12. Reversing gear disengaged, test for infinite resistance between the K20 Engine Control Module X1 or X2 harness connector terminal listed below and ground:

• X1 Terminal 34 with LBY

• X2 Terminal 75 with LBS

• X1 Terminal 18 with LDK or LBW

• X2 Terminal 82 with LLU

13. If lower then the specified value, test or replace the B16 Backup Lamp Switch.

14. If all the circuits test normal, replace the K20 Engine Control Module.


Component Testing


Static Test

1. Ignition OFF, disconnect the harness connector at the B16 Backup Lamp Switch. Reversing gear engaged, test for less than 5 Ω at the B16 Backup Lamp Switch terminal 1 and terminal 2.

2. If greater than the specified value replace the B16 Backup Lamp Switch.

3. Reversing gear disengaged, test for infinite resistance at the B16 Backup Lamp Switch terminal 1 and terminal 2.

4. If less than the specified value replace the B16 Backup Lamp Switch.


Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.


• Tail Lamp Replacement

• Backup Lamp Switch Replacement for the F40 transmission.

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