IMPORTANT:

1. Inspect the condition of the horn fuse. If fuse is open, locate and repair source of overload.
2. If any vehicle DTCs are set, refer to Diagnostic System Check - Body Control System .
3. Verify that ground G100 is clean and tight.

Using a scan tool, command the horns ON and OFF.

Do the horns sound?

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Go to Step 2

Go to Step 3

Locate and repair open in CKT 28 (BLK) between the horn relay and the horn switch. If ok replace the horn switch.

Is the repair complete?

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System OK

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1. Use the appropriate probe from the J35616-A connector test adapter kit connect a test lamp between the horn fuse (located in the underhood bussed electrical center UBEC) and ground.
2. Command the horns on and off.

Does the test lamp light?

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Go to Step 7

Go to Step 4

1. Disconnect the horn relay.
2. Use the appropriate probe from the J35616-A connector test adapter kit connect a test lamp between cavity 30 and ground.

Does the test lamp light?

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Go to Step 5

Go to Step 6

Replace the horn relay.

Is the repair complete?

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System OK

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Locate and repair the open between the horn relay and the power distribution.

Is the repair complete?

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System OK

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1. Disconnect the inoperative horn connector.
2. Connect a test lamp between CKT 150 (BLK) cavity B and battery positive.

Does the test lamp light?

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Go to Step 9

Go to Step 8

Locate and repair open in CKT 150 (BLK) between the inoperative horn and ground.

Is the repair complete?

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System OK

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1. Connect a test lamp between CKT 1329 (DK GRN) cavity A and ground.
2. Command the horn ON.

Does the test lamp light?

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Go to Step 10

Go to Step 11

Replace the inoperative horn. Refer to Horn Replacement .

Is the repair complete?

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System OK

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Locate and repair open in CKT 1329 (DK GRN) between the inoperative horn and the horn fuse.

Is the repair complete?

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System OK

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