Test A: The Courtesy Lamps Are Inoperative

PINPOINT TEST A: THE COURTESY LAMPS ARE INOPERATIVE

Normal Operation
Power is supplied to the courtesy lamps through the smart junction box (SJB) fuse 3 (15A), which supplies voltage to the courtesy lamps relay, the demand lamps relay (Fusion, Milan only), and the demand lamps field-effect transistor (FET) (MKZ only). When any door is opened, the ajar switch opens, signaling the SJB to activate the courtesy lamps. The SJB monitors the ajar circuits, and based on the ajar status, the SJB will supply voltage to the courtesy lamps on circuit CLN26 (BU). Ground for the courtesy lamps is supplied through circuit GD139 (BK/YE) or GD126 (BK/WH).

- DTC B2499 (Courtesy Lamp Output Failure) - sets when the FET output has been disabled due to an over-current fault on circuit CLN26 (BU). This continuous DTC applies to MKZ only, and it can only be cleared once the fault has been repaired and the on-demand self-test is re-run.

This pinpoint test is intended to diagnose the following:
- Fuse
- Wiring, terminals or connectors
- SJB

A1:

A2-A4: