Test B: The Horn Is Always On

PINPOINT TEST B: THE HORN IS ALWAYS ON

B1-B2:

B3-B8:

B9:

Normal Operation
When the horn switch is pressed, the instrument cluster receives a ground through signal circuit 10-GJ9 (GY/OG), the clockspring and ground circuit 31-GJ9 (BK/GN). The horn relay control and switched B+ power circuits are supplied by auxiliary junction box fuse 4 (15A) 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 communication network 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). The horn is grounded through circuit 31-GJ6 (BK).

Possible Causes
- auxiliary junction box fuse 4 (15A)
- circuit 10-GJ9 (GY/OG) short to ground
- circuit 30S-GJ6 (RD/YE) short to voltage
- circuit 91S-GJ7 (BN/RD) short to ground
- clockspring
- horn relay
- horn
- horn switch
- instrument cluster
- FEM