For 1990-2009 cars

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
1 | Was the Horns Diagnostic System Check performed? | -- | Go to Step 2 | Refer to Horns System Check .
2 | Remove the horn relay K63 from the relay box. Do the horns still sound? | -- | Go to Step 3 | Go to Step 4
3 |

1. Locate a short to ground in the following circuits:

• | XM30

• | XM60

• | XM65

• | XM70

2. Repair the short to ground in any one of these circuits.

Is the repair complete?

--

Go to Step 9

--

4 | Using a DMM, measure the resistance from terminal 6 of the horn relay K63 and a known good ground. Is the measured resistance within the specified value? | Value less than 5ohms | Go to Step 5 | Go to Step 7
5 |

1. Disconnect the horn switch.
2. Use a DMM in order to measure the resistance from terminal 6 of the horn relay K63 and a known good ground.

Is the measured resistance within the specified value?

Less than 5ohms

Go to Step 6

Go to Step 8

6 |

1. Locate a short to ground in CKT XM1 and/or CKT XM899.
2. Replace the BCM if CKT XM899 and/or CKT XM1 is OK.

Refer to Body Control Module.

Is the repair complete?

--

Go to Step 9

--

7 | Replace the horn relay K63. Is the replacement complete? | -- | Go to Step 9 | Go to Step 5
8 |

1. Replace the horn switch.
2. Refer to Horn Switch Replacement - On Vehicle in Steering Wheel and Column On-Vehicle Service.

Is the replacement complete?

--

Go to Step 9

--

9 |

1. Connect all the connectors and components that were disconnected.
2. Verify that both horns operate properly.

Do both of the horns operate properly?

--

System OK

Go to Step 1