DTC B15A8 or B191A

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 B15A8 Rear Footwell Accent Lighting Control DTC B191A Front Footwell Accent Lighting Control Diagnostic Fault Information

Circuit	Circuit Function	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performan
4783	Control	B15A8 11	1	1	—
7558	Control	B191A 11	1	1	—
1150	Ground	—	1	—	—
1250	Ground	—	1	—	—
1. Door Sill Illumination Malfunction

Circuit/System Description The Ambient Light Sensor provides a voltage signal that will vary between 0.2 and 4.9 V depending on outside lighting conditions. The door sill illumination lamps (B7G/S0M) become illuminated anytime the ignition is on during dark ambient light conditions. Conditions for Running the DTC Ignition on/vehicle in service mode Dark ambient light conditions Conditions for Setting the DTC B15A8 11 The K9 Body Control Module detects a short to ground on circuit 4783 B191A 11 The K9 Body Control Module detects a short to ground on circuit 7558 Action Taken When the DTC Sets B15A8 11 The K9 Body Control Module will not apply voltage to circuit 4783 B191A 11 The K9 Body Control Module will not apply voltage to circuit 7558 Conditions for Clearing the DTC The DTC becomes history when the K9 Body Control Module no longer detects the condition that set the DTC. 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/vehicle off, disconnect the appropriate connector at the K9 Body Control Module: B15A8 = Connector X7 B191A = Connector X1
2. Connect a 3 A fused jumper wire between the appropriate control circuit terminal and B+: B15A8 = Terminal 24 X7 B191A = Terminal 4 X1
3. Verify the appropriate door sill plate lamps turn on and off when connecting and disconnecting the jumper wire: B15A8 = E8 Rear Side Door Sill Plate Lamps B191A = E8 Front Side Door Sill Plate Lamps ⇒ If a door sill plate lamp(s) is always off and the jumper fuse is OK. 3.1. Test the appropriate control circuit for an open/high resistance: B15A8 = Circuit 4783 B191A = Circuit 7558 ⇒ If an open/high resistance is found, repair the fault on the circuit. ⇓ If an open/high resistance is not found. 3.2. Replace the appropriate door sill lamp. ⇒ If a door sill plate lamp(s) is always off and the jumper fuse is open 3.1. Test the appropriate circuit for a short to ground: B15A8 = Circuit 4783 B191A = Circuit 7558 ⇒ If a short to ground is found, repair the fault on the circuit. ⇓ If a short to ground is not found. 3.2. Replace the appropriate door sill lamp. ⇒ If a door sill plate lamp(s) is always on 3.1. Test the appropriate circuit for a short to voltage: B15A8 = Circuit 4783 B191A = Circuit 7558 ⇒ If a short to voltage is found, repair the fault on the circuit. ⇓ If a short to voltage is not found. 3.2. Replace the appropriate door sill lamp. ⇓ If the door sill plate lamps turn on and off
4. Replace the K9 Body Control Module. Repair Instructions Perform the Diagnostic Repair Verification after completing the repair. Lighting Component Replacement Reference Control Module References for BCM replacement, programming, and setup