Test Description

WARNING: This page does not describe the selected car, but rather 7 other vehicles, including the 2002 GMC Yukon XL, 2002 GMC Yukon, 2002 Chevrolet Tahoe, 2002 Chevrolet Suburban, and 2002 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.

The numbers below refer to the step numbers on the diagnostic table.

4: Tests if ground is constantly being applied to the horn relay.
5: The horn relay control circuit includes the horn switch. The horn switch must be tested for a short to ground when testing the relay control circuit.

Horns Always On

Step	Action	Yes	No
1	Did you perform the Horns Diagnostic System Check?	Go to Step 2	Go to Diagnostic System Check - Horns
2	Install a scan tool. Turn ON the ignition, with the engine OFF. With a scan tool, command the body control module Horn Output ON and OFF. Are the horns on at all times?	Go to Step 3	Go to TESTING FOR INTERMITTENT AND POOR CONNECTIONS
3	Turn OFF the ignition. Disconnect the horn relay. Are the horns on at all times?	Go to Step 8	Go to Step 4
4	Connect a test lamp between the battery positive voltage circuit of the horn relay coil and the horn relay control circuit. Does the test lamp illuminate?	Go to Step 5	Go to Step 6
5	IMPORTANT: The horn switch is part of the inflatable restraint steering wheel module. Refer to REMOVAL & INSTALLATION (DRIVER-SIDE) . To disable the SIR system, refer to DISABLING SYSTEM . Test the horn relay control circuit for a short to ground. The horn relay control circuit includes the horn switch. Refer to CIRCUIT TESTING or WIRING REPAIRS .Did you find and correct the condition?	Go to Step 11	Go to Step 7
6	Inspect for poor connections at the horn relay. Refer to TESTING FOR INTERMITTENT AND POOR CONNECTIONS and CONNECTOR REPAIRS . Did you find and correct the condition?	Go to Step 11	Go to Step 9
7	Inspect for poor connections at the body control module. Refer to TESTING FOR INTERMITTENT AND POOR CONNECTIONS and CONNECTOR REPAIRS . Did you find and correct the condition?	Go to Step 11	Go to Step 10
8	Repair the short to voltage in the horn control circuit. Refer to CIRCUIT TESTING or WIRING REPAIRS . Did you complete the repair?	Go to Step 11	-
9	Replace the horn relay. Did you complete the replacement?	Go to Step 11	-
10	IMPORTANT: Perform the BCM programming procedure when replacing the BCM. Replace the BCM. Refer to BODY CONTROL MODULE REPLACEMENT .Did you complete the replacement?	Go to Step 11	-
11	Operate the horn. Do the horns operate properly?	System OK	Go to Step 1