Tests AG

PINPOINT TEST AG: THE HORN IS ALWAYS ON

Test AG1:

Test AG2-AG6:

Test AG7-AG9:

Normal Operation
The horn switches are grounded through the clockspring by circuit 31-GJ1 (BK/BU). The clockspring provides this ground signal to the instrument cluster through the horn switch on circuit 10-GJ9 (GY/OG). The horn relay control and switched B+ power circuits are supplied by auxiliary junction box fuse 4 (20A) through circuit 30-GJ7 (RD/BU). The horn relay ground is controlled by the front electronic module (FEM) through circuit 91S-GJ7 (BN/RD). When the horn switch is pressed, the instrument cluster sends the FEM a command signal over the standard corporate protocol (SCP) communication network, circuits 4-EG8 (GY/VT) and 5-EG8 (BU/WH) to ground the horn relay. The FEM supplies a ground, energizing the horn relay and supplying power to the horn through circuit 30S-GJ6 (RD/YE).

Possible Causes
- auxiliary junction box fuse 4 (20A)
- circuit 10-GJ9 (GY/OG) shorted to ground
- circuit 30S-GJ6 (RD/YE) shorted to power
- circuit 91S-GJ7 (BN/RD) shorted to ground
- clockspring
- horn relay
- horn
- horn switches
- FEM
- instrument cluster