Test A: The Courtesy Lamps Are Inoperative

PINPOINT TEST A: THE COURTESY LAMPS ARE INOPERATIVE

A1-A2:

A2-A3:

A3-A5:

A5-A6:

A7-A8:

A9-A10:

Normal Operation
Power is supplied to the smart junction box (SJB) through the bussed electrical center (BEC) fuse 67 (30A) to the SJB. When a door is opened, the ajar switch opens, signaling the SJB. The SJB monitors the ajar circuits, and based on the ajar status, the SJB will supply voltage to the courtesy lamps on circuit 53 (BK/LB). Ground for the courtesy lamps is supplied by the SJB through circuit 54 (LG/YE).

DTC B2021 - sets when the SJB detects a short to voltage on the dome lamp return circuit.

DTC B2550 - sets when the SJB detects a short to ground on the dome lamp output supply circuit.

DTC B2554 - sets when the SJB detects an open on the dome lamp supply or return circuits.

Possible Causes
- Fuse
- Circuit 53 (BK/LB) open or short to ground
- Circuit 54 (LG/YE) open or short to voltage
- Interior lamp
- SJB