DTC 007

DTC 007

CIRCUIT DESCRIPTION
The vehicle horns are activated whenever ground is applied to the horn relay coil through the horn relay control circuit. Ground may be applied by any of the following:
- The body control module (BCM)
- The horn switch
- The vehicle interface unit (VIU)

CONDITIONS FOR RUNNING THE DTC
- The body control system voltage is between 9.0 and 16.0 volts.
- The BCM commands the horn relay on.

CONDITIONS FOR SETTING THE DTC
The BCM will set DTC 7 under either of the following conditions:
- The BCM detects a short to ground in the horn relay control circuit.
- The BCM detects a short to voltage in the horn relay control circuit.

ACTION TAKEN WHEN THE DTC SETS
- If the horn relay control circuit is shorted to ground the horns will remain on at all times.
- If the horn relay control circuit is shorted to voltage the horns will not operate from the horn switch(es) or when energized from either the BCM or the VIU.
- The BCM stores DTC 7 in memory.

CONDITIONS FOR CLEARING THE DTC
A DTC will clear when the fault is no longer present and the DTCs are cleared as described in Body Control Systems. Refer to On-Board Diagnostic Features in Body Control System. Reading and Clearing Diagnostic Trouble Codes

DIAGNOSTIC AIDS
- Inspect for a sticking horn pad and or switch.
- Perform a visual inspection for loose or poor connections at all related components.

TEST DESCRIPTION

Steps 1 - 6:

Steps 7 - 11:

Steps 12 - 13:

The numbers below refer to the step numbers on the diagnostic table.
3. Tests for voltage at the coil side of the horn relay. The HORN fuse supplies power to the coil side of the horn relay.
5. Tests if ground is constantly being applied to the horn relay.