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 SJB fuse 13 (15A) through circuit SBB05 (GY/RD). The horn relay (part of the SJB) is controlled by circuit SRH01 (YE/RD) through the clockspring to the horn switch (part of the steering wheel). When the horn switch is pressed, the horn relay control circuit SRH01 (YE/RD) is grounded through the steering wheel switch harness (part of the steering wheel). The horn relay is then energized causing voltage to be applied to circuit CRH02 (BU/WH), enabling the horn to sound. Ground to the horn is supplied through circuit GD123 (BK/GY).

- DTC B1897 (Horn Switch Circuit Failure) - is a continuous and on-demand DTC that sets when the SJB detects a short to ground on the horn switch circuit SRH01 (YE/RD).

This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Clockspring
- Horn switch (part of the steering wheel)
- SJB

B1-B5: