Test D: The Steering Wheel Control Illumination Is Inoperative

PINPOINT TEST D: THE STEERING WHEEL CONTROL ILLUMINATION IS INOPERATIVE

Normal Operation
The smart junction box (SJB) sends a pulse width modulated (PWM) voltage to the steering wheel controls through circuit VLN04 (VT/GY) (Edge) or circuit VLN37 (BU/WH) (MKX) to the clockspring. The voltage passes through the clockspring to the steering wheel control switches. Ground to the clockspring is supplied through circuit GD116 (BK/VT).

This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Steering wheel control switch(es)
- Steering wheel control switch harness
- Clockspring

D1-D4:

D4-D5:

D5-D6: