Test D: The Steering Wheel Control Illumination Is Inoperative

PINPOINT TEST D: THE STEERING WHEEL CONTROL ILLUMINATION IS INOPERATIVE

D1-D2:

D2-D4:

D4-D5:

Normal Operation
The smart junction box (SJB) sends a pulse-width modulated (PWM) voltage to the steering wheel controls through circuit VLN04 (VT/GY) (Navigator) or VLN18 (BU/WH) (Expedition) to the clockspring. The voltage passes through the clockspring to the steering wheel control switch harness and on to the steering wheel controls. Ground is provided through the clockspring and circuit GD133 (BK).

Possible Causes
- Circuit VLN04 (VT/GY) open
- Circuit VLN18 (BU/WH) open
- Circuit GD133 (BK) open
- Steering wheel control switch harness
- Steering wheel control switch(es)
- Clockspring