DTC B1A2F

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 B1A2F Dome/Reading Lamp Enable 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
4786	Control	B1A2F 11	1	1	—
1250	Ground	—	1	—	—
1. Courtesy Lamps Malfunction

Circuit/System Description The K9 Body Control Module (BCM) supplies battery voltage to the center console lamp through control circuit 4786 anytime the ignition is on/vehicle in service mode. When the center console compartment lid is opened, the switch contacts close allowing battery voltage to flow through control circuit 4786 illuminating the center console lamp. In the event that the center console lamp were to remain illuminated for more than 10 minutes with the ignition switch in the OFF position, the BCM will deactivate the control circuit to prevent total battery discharge. Conditions for Running the DTC Battery voltage must be between 9–16 V. Conditions for Setting the DTC The BCM detects a short to ground on circuit 4786 Actions Taken When the DTC Sets The BCM will disable control circuit 4786. 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 Interior Lights Schematics Connector End View Reference Master Electrical Component List Description and Operation Interior 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

1. Ignition OFF, disconnect the connector at the E28 Front Floor Console Compartment Lamp.
2. 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 circuit 1250 or ground connection. ⇓ If the test lamp illuminates
3. Ignition on/vehicle in service mode, verify a test lamp illuminates between control circuit terminal 2 and ground. ⇒ If the test lamp does not illuminate 3.1. Test circuit 4786 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 3.2. Test circuit 4786 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 3.3. Replace the K9 Body Control Module. ⇓ If the test lamp illuminates
4. Replace the center console 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