DTC B1A4F
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 B1A4F Rear Closure Hands Free Lamp Control Refer to Symptom Byte List for symptom byte information. Diagnostic Fault Information
| Circuit | Circuit Function | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performan |
|---|---|---|---|---|---|
| 2066 | Control | B1A4F 11 | 1 | 1 | — |
| 1450 | Ground | — | 1 | — | — |
| 1. Rear Closure Hands Free Lamp Malfunction |
Scan Tool Functions K9 Body Control Module – Control Functions – Exterior Lighting
| Control Function | Description |
|---|---|
| Hands-Free Sensor Lamp Command | This control function will control the hands-free sensor lamp ON/OFF |
Circuit/System Description The rear closure hands free lamp illuminates the vehicle’s brand logo in the area where the sensor for the foot activated liftgate actuator is located for hands free liftgate operation. When the keyless entry transmitter is operated to either the lock or unlock functions, the rear closure hands free lamp is commanded ON by the K9 Body Control Module. The rear closure hands free lamp will display the image of the vehicle’s brand logo on the ground directly under the center of the rear bumper. Conditions for Running the DTC Battery voltage must be between 9-16 V. Hands-free liftgate sensor lamp commanded on. Conditions for Setting the DTC The BCM detects a short to ground on circuit 2066. Actions Taken When the DTC Sets The hands-free liftgate sensor lamp is inoperative. Conditions for Clearing the DTC The condition responsible for setting the DTC no longer exists. A history DTC will clear once 40 consecutive malfunction-free ignition cycles have occurred. 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, disconnect the connector at the E72 Rear Closure Hands Free Lamp.
- Verify a test lamp illuminates between ground circuit terminal 2 and B+. ⇒ If the test lamp does not illuminate 2.1. Repair the open/high resistance on circuit 1450 or ground connection. ⇓ If the test lamp illuminates
- Connect a test lamp between control circuit terminal 1 and ground, ignition on/vehicle in service mode.
- Verify the test lamp turns ON and OFF when commanding the Hands-Free Sensor Lamp Command ON and OFF with a scan tool. ⇒ If the test lamp is always OFF 4.1. Test circuit 2066 for a short to ground. ⇒ If a short to ground is found, repair the fault on the circuit. ⇓ If a short to ground is not found 4.2. Test circuit 2066 for an open/high resistance. ⇒ 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 K9 Body Control Module. ⇒ If the test lamp is always ON 4.1. Test circuit 2066 for a short to voltage. ⇒ 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 K9 Body Control Module. ⇓ If the test lamp turns ON and OFF
- Replace the E72 Rear Closure Hands Free 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