Symptom Related Diagnostic Procedures

*HORNS INOPERATIVE





For a complete wiring diagram refer to Diagrams/Electrical.





Diagnostic Test

1. RELATED DTC'S

Turn the ignition on.

With the scan tool, read the current IPM DTC's.

Does the scan tool display any Horn related DTC's?

Yes

- Refer to Ignition, Power, Accessory for the related symptom(s).
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test

No

- Go To 2

2. ACTUATE HORN RELAY

With the scan tool, actuate the Horn Relay.

Do the horns operate?

Yes

- Go To 3

No

- Go To 7

3. HORN SWITCH GROUND

WARNING: Turn the ignition off, disconnect the battery and wait two minutes before proceeding.

WARNING: Do not place an intact undeployed airbag face down on a hard surface, the airbag will propel into the air if accidentally deployed, and could result in serious or fatal injury.

Gain access to the horn switch.

Inspect the Horn Switch ground circuit.

Is the Horn Switch ground wire connected properly?

Yes

- Go To 4

No

- Repair the horn switch ground as necessary.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test

4. HORN SWITCH

WARNING: Turn the ignition off, disconnect the battery and wait two minutes before proceeding

CAUTION: Do not place an intact undeployed airbag face down on a hard surface, the airbag will propel into the air if accidentally deployed, and could result in serious or fatal injury.

Gain access to the horn switch connector.

WARNING: Turn the ignition on, then reconnect the battery.

Momentarily connect a jumper wire between the (X3) Horn Switch Sense circuit at the horn switch pigtail connector and ground.

Did the horns sound?

Yes

- Repair or replace the wiring/horn switch as necessary.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test

No

- Go To 5

5. CLOCKSPRING





Disconnect the clockspring C1 connector.

Momentarily connect a jumper wire between the (X3) Horn Switch Sense circuit at the clockspring connector and ground.

Did the horns sound?

Yes

- Replace the clockspring.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test

No

- Go To 6

6. (X3) HORN SWITCH SENSE





Disconnect the clockspring C1 connector.

Disconnect the Integrated Power Module C4 connector.

NOTE: Check connectors - Clean/repair as necessary.

Measure the resistance of the (X3) Horn Switch Sense circuit between the clockspring C1 connector and the Integrated Power Module C4 connector.

Is the resistance below 5.0 ohms?

Yes

- Replace the Integrated Power Module.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test

No

- Repair the (X3) Horn Switch Sense circuit for an open.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test

7. INSTALL KNOWN GOOD RELAY

Turn the ignition off.

Remove the Horn Relay from the Integrated Power Module.

Substitute the original Horn Relay with a known good relay.

Turn the ignition on.

With the scan tool actuate the Horn Relay.

Do the Horns operate?

Yes

- Replace the original Horn Relay.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test

No

- Go To 8

8. (X2) HORN RELAY OUTPUT CIRCUIT OPEN





Disconnect each horn connector.

With the scan tool, actuate the horn relay.

Using a 12-volt test light connected to ground, check for voltage at the (X2) Horn Relay Output circuit at each horn connector.

Does the test light illuminate brightly at both connectors?

Yes

- Go To 9

No

- Repair the (X2) Horn Relay Output circuit for an open.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test

9. (Z298/Z299) HORN GROUND CIRCUIT OPEN





Disconnect the Horn connectors.

Using a 12-volt test light connected to 12-volts, check the (Z298/Z299) Ground circuits in the horn connectors.

Does the test light illuminate brightly?

Yes

- Replace the Horns as necessary.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test

No

- Repair the (Z298/Z299) Ground circuit for an open.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test