Test B: The Horn Is Always On

PINPOINT TEST B: THE HORN IS ALWAYS ON

B1-B7:

Normal Operation
The horn relay is controlled through circuit 1 (DB) by the horn switch and through the lighting control module (LCM). When the horn switch is pressed, the horn relay control circuit 1 (DB) is grounded through the clockspring to the vehicle harness. The horn relay is then energized causing voltage to be applied to circuit 6 (YE/LG), enabling the horn to sound.

When the LCM has enabled the anti-theft system, the LCM supplies a ground through the horn relay control circuit 1 (DB). The horn relay is then energized causing voltage to be applied to circuit 6 (YE/LG), enabling the horn to sound.

Possible Causes
- Circuit 1 (DB) short to ground
- Circuit 6 (YE/LG) short to voltage
- Horn relay
- LCM
- Clockspring
- Horn switch (part of the driver air bag module)
- Steering wheel switch harness