Test B: The Horn Is Always On

PINPOINT TEST B: THE HORN IS ALWAYS ON

B1-B6:

Normal Operation
The horn relay control voltage and the horn relay switched voltage circuits are supplied by the central junction box (CJB). The horn relay is controlled by circuit 1 (DB) through the vehicle security module and the horn switch. When the horn switch is pressed, the horn relay is grounded through circuit 1 (DB) to the powertrain control module (PCM). The relay is then energized causing voltage to be applied to circuit 6 (YE/LG), enabling the horns to sound. The vehicle security module also provides a momentary ground to the horn relay control circuit 1 (DB), causing the horns to sound.

DTC B2848 - sets when the vehicle security module detects a short to ground on the horn relay output circuit.

Possible Causes
- Circuit 1 (DB) short to ground
- Circuit 6 (YE/LG) short to voltage
- CJB
- Clockspring
- Horn switch (part of the driver air bag module)
- Vehicle security module