The body control module (BCM) controls the operation of the horn for the security
system and remote keyless entry (RKE) functions. Circuit 28 is grounded by
the BCM when horn operation is desired for RKE or security function. Normal operation
of the horn is performed by the horn switch grounding the horn relay and is not controlled
by the BCM.
DTC Parameters
| • | The horn operation is requested by the BCM. |
| • | Circuit 28 is shorted-to-battery voltage. |
Diagnostic Aids
| • | When a shorted-to-battery voltage condition exists in circuit 28
and the BCM requests operation of the horns, the BCM will attempt to switch circuit 28
to ground. High current flow will result and the BCM output will go into a protective
state. The BCM output will not allow itself to be activated for as much as 3 minutes.
The BCM is protected. Damage will not result. |
| • | Inspect the wiring harness for damage. Check for broken or chafed insulation. |
| • | Check for a poor connection at the rear defrost switch. |
| • | If a fault is suspected to be intermittent, wiggling the harness wiring
may help in locating the fault. |
