Navigator 4WD V8-5.4L (2010)
Parking Lamp: Initial Inspection and Diagnostic Overview
Special Tool(s) Used With Diagnostics
Parking, Rear and License Plate Lamps
Principles of Operation
Parking, Rear and License Plate Lamps
Principles of Operation
NOTE: The Smart Junction Box (SJB) is also known as the Generic Electronic Module (GEM).
The SJB monitors the headlamp switch position by sending voltage signals on multiple circuits to the headlamp switch. There is one circuit for each
headlamp switch position. At any given time, one of the signal circuits is switched to ground.
If the SJB does not detect any of the inputs to the headlamp switch are active (switched to ground) for 5 seconds, the SJB turns the parking lamps and
headlamps on and keeps them on until the battery saver feature times out.
Additionally, if the SJB detects multiple headlamp switch input circuits short to ground, the SJB turns the parking lamps and headlamps on and keeps
them on until the battery saver feature times out.
Refer to Exterior Lighting See: Description and Operation/Exterior Lighting for information regarding the Battery Saver feature.
If either situation occurs, the SJB cannot be ruled immediately as being at fault. This is normal behavior of the SJB design as it has detected a fault with
the inputs from the headlamp switch.
When the SJB receives an input from the headlamp switch indicating a request for the parking lamps, the SJB energizes the parking lamp relay, which
supplies voltage to the exterior lamps.
Inspection and Verification
Parking, Rear and License Plate Lamps
Inspection and Verification
1. Verify the customer concern.
