DEFINITION: One or both of the horns are inoperative.

Was the Horns System Check performed?

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Go to Step 2

Go to Horns System Check

1. Install the scan tool.
2. Select the miscellaneous test in special functions.
3. Command the BCM to turn ON the horns.

Do both horns sound for as long as the BCM has the horns turned ON?

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Go to Step 13

Go to Step 3

1. Disconnect the horn #1 connector.
2. Using the DMM, measure the voltage between terminal 2 of the horn #1 connector and a known good ground.
3. Repeat steps 1 and 2 for horn #2.

Is the measured voltage equal to the specified value?

B+

Go to Step 5

Go to Step 4

1. Inspect the horn fuse for an open.
2. If the horn fuse is OK, locate and repair an open or a high resistance in one of the following circuits:

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A17

•

A18

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A30

•

301

Is the repair complete?

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Go to Step 17

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1. Connect the horn #1 and horn #2 connectors.
2. Remove the horn relay K63 from the relay box.
3. Connect a fused jumper between terminal 4 and terminal 8 of the relay box.

Do both horns sound?

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Go to Step 7

Go to Step 6

1. Locate and repair an open or a high resistance in circuits XM60, XM65, XM70, XM30 and/or F700.
2. If all of these circuits are OK, replace horn #1 and/or horn #2. Refer to Horn Replacement .

Is the repair or replacement complete?

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Go to Step 17

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Using the DMM, measure the voltage between terminal 2 of the horn relay K63, and a known good ground.

Is the measured voltage equal to the specified value?

B+

Go to Step 9

Go to Step 8

Locate and repair an open or a high resistance in circuit A121.

Is the repair complete?

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Go to Step 17

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While commanding the BCM to activate the horns, use the DMM in order to measure the voltage between terminal 2 and 6 of the horn relay K63.

Is the measured voltage equal to the specified value?

B+

Go to Step 10

Go to Step 11

Replace the horn relay K63. Refer to Horn Relay Replacement .

Is the replacement complete?

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Go to Step 17

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1. Disconnect the BCM connector C2.
2. Using the DMM, measure the resistance between terminal 6 of the relay box and terminal C4 of the BCM connector C2.

Is the measured resistance less than the specified value?

5 ohms

Go to Step 16

Go to Step 12

Locate and repair an open or a high resistance in circuit XM899.

Is the repair complete?

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Go to Step 17

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1. Remove the horn switch.
2. Remove the horn relay K63 from the relay box.
3. Connect a jumper between terminal A and terminal B of the horn switch connector.
4. Using the DMM, measure the resistance between terminal 6 of the relay box and a known good ground.

Is the measured resistance less than the specified value?

5 ohms

Go to Step 15

Go to Step 14

1. Locate and repair an open or a high resistance in circuits XM1, X1 and/or F122.
2. Replace the inflatable restraint steering wheel module coil if these circuits are OK. Refer to Inflatable Restraint Steering Wheel Module Coil Replacement in SIR.

Is the repair complete?

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Go to Step  17

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

Is the replacement complete?

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Go to Step  17

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Replace the BCM. Refer to Body Control Module Replacement .

Is the replacement complete?

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Go to Step  17

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

Do both of the horns operate properly?

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System OK

Go to Step 1