Test B: The Horn Is Always On

PINPOINT TEST B: THE HORN IS ALWAYS ON

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 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 (Horn Output Relay Circuit Short to Ground) - is a continuous DTC that sets when the vehicle security module detects a short to ground on the horn relay output circuit.

This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- CJB
- Clockspring
- Horn switch (part of the driver air bag module)
- VSM

B1-B2:

B3-B6: