GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2003 🢒 CTS 🢒 Body and Accessories 🢒 Horns 🢒 Horns - Poor Tone

Step

Action

Yes

No

1

Did you perform the Horns Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - Horns

2

Depress the horn switch.

Do the horns have a harsh tone or buzzing?

Go to Step 3

Go to Symptoms - Horns

3
    • Test the horn mounting hardware for adequate torque. Refer to Fastener Tightening Specifications .
    • Inspect the horns for debris in the joint where the horns attach to the vehicle.

Did you find and correct the condition?

Go to Step 7

Go to Step 4

4

Perform the following for each of the horns:

  1. Disconnect the horn connector.
  2. Connect a 15 amp fuse jumper wire between the positive battery terminal and the control terminal of the horn.
  3. Connect another jumper wire between the negative battery terminal and the ground terminal of the horn.

Does the horn have a harsh tone or buzzing?

Go to Step 6

Go to Step 5

5

Repair the high resistance in the horn control circuit or the horn ground circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 7

--

6

Replace the horn. Refer to Horn Replacement .

Did you complete the replacement?

Go to Step 7

--

7

Operate the horns.

Do the horns operate properly?

System OK

Go to Step 1