Test Q: The Parking, Rear or License Plate Lamps Are On Continuously

PINPOINT TEST Q: THE PARKING, REAR OR LICENSE PLATE LAMPS ARE ON CONTINUOUSLY

Q1-Q3:

Q4-Q10:

Normal Operation
The smart junction box (SJB) sends a reference signal to the headlamp switch through circuit CLS34 (GY) to monitor for a parking lamp on request. When the headlamp switch is placed in the PARKING LAMPS ON position, the voltage signal is routed to ground. The SJB provides a ground for the parking lamp relay coil when a request for the parking lamps is received. When the parking lamp relay is energized, voltage is sent through circuit CBP26 (BU/WH or WH/BU) to the rear and front parking lamps.

DTC B1578 - is an on-demand DTC that sets when the SJB detects a short to ground from the parking lamp request input circuit.

Possible Causes
- Circuit CAT17 (BN) short to voltage
- Circuit CLS34 (GY) short to ground
- Circuit CBP26 (BU/WH or WH/BU) short to voltage
- Parking lamp relay
- Climate control assembly
- Headlamp switch
- SJB