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 provides an overview of each diagnostic category. Diagnostic Fault Information
| Circuit | Circuit Function | Short to Ground | Open/Hig Resistance | h Short to Voltage | Signal Performan |
|---|---|---|---|---|---|
| 24 | Control | B1236 11 | B1236 13 | 1 | — |
| 1324 | Control | B1AE7 11 | B1AE7 13 | 1 | — |
| 1950 | Ground | — | 1 | — | — |
| 2050 | Ground | — | 1 | — | — |
| 1. Backup Lamps Malfunction |
Scan Tool Functions K219 Lighting Control Module – Control Functions – Exterior Lighting
| Control Function | Description |
|---|---|
| Backup Lamps | This control function will control the rear backup lamps ON/OFF |
Circuit/System Description With the engine running and the transmission in the reverse position, the transmission control module (TCM) sends a serial data message that the transmission is in the reverse position. The K219 Lighting Control Module responds by applying battery voltage to the backup lamp control circuits illuminating the backup lamps. Once the driver moves the gear selector out of the reverse position, a serial data message is sent by the TCM that the transmission is no longer in reverse. The lighting control module responds by removing battery voltage from the backup lamp control circuits. The engine must be running for the backup lamps to operate. Reference Information Schematic Reference Exterior Lights Schematics Connector End View Reference Master Electrical Component List 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 scan tool information Circuit/System Testing
- Ignition/vehicle OFF, exterior lamps OFF, disconnect the appropriate component: E42L Rear Body Structure Stop Lamp - Left E42R Rear Body Structure Stop Lamp - Right
- Verify a test lamp illuminates between ground circuit terminal 1 and B+. ⇒ If the test lamp does not illuminate 2.1. Repair the open/high resistance on the ground circuit or ground connection. ⇓ If the test lamp illuminates
- Connect a test lamp between the control circuit terminal 4 and ground, ignition ON.
- Verify the test lamp turns ON and OFF when commanding the appropriate Backup Lamps ON and OFF with a scan tool. ⇒ If the test lamp is always OFF 4.1. Test the appropriate circuit for a short to ground: E42L Rear Body Structure Stop Lamp - Left = Circuit 24 E42R Rear Body Structure Stop Lamp - Right = Circuit 1324 ⇒ If a short to ground is found, repair the fault on the circuit. ⇓ If a short to ground is not found 4.2. Test the appropriate circuit for an open/high resistance: E42L Rear Body Structure Stop Lamp - Left = Circuit 24 E42R Rear Body Structure Stop Lamp - Right = Circuit 1324 ⇒ If an open/high resistance is found, repair the fault on the circuit. ⇓ If an open/high resistance is not found 4.3. Replace the K219 Lighting Control Module. ⇒ If the test lamp is always ON 4.1. Test the appropriate circuit for a short to voltage: E42L Rear Body Structure Stop Lamp - Left = Circuit 24 E42R Rear Body Structure Stop Lamp - Right = Circuit 1324 ⇒ If a short to voltage is found, repair the fault on the circuit. ⇓ If a short to voltage is not found 4.2. Replace the K219 Lighting Control Module. ⇓ If the test lamp turns ON and OFF
- Replace the appropriate E5 Backup Lamp. Repair Instructions Perform the Diagnostic Repair Verification after completing the repair. Lighting Component Replacement Reference Control Module References for BCM replacement, programming, and setup