Diagnostic Routine B

Diagnostic Routine B

Diagnostic Overview

The Horn Is Always On

Refer to Wiring Diagram Set 44 for schematic and connector information Electrical Diagrams.

Normal Operation and Fault Conditions

REFER to Horn Operation .

Pinpoint Test

1. ISOLATE THE HORN RELAY

1. Remove the horn relay.

Does the horn continue to sound?







2. SUBSTITUTE A KNOWN GOOD HORN RELAY

1. Install a known good the horn relay.

Does the horn continue to sound?







3. ISOLATE THE BCM (Body Control Module) HORN OUTPUT CIRCUIT

1. Ignition OFF.

2. Disconnect: BCM (Body Control Module) C2280A.

Does the horn continue to sound?







4. ISOLATE THE BCM (Body Control Module) HORN INPUT CIRCUIT

1. Connect: BCM (Body Control Module) C2280A.

2. Disconnect: BCM (Body Control Module) C2280C.

Does the horn continue to sound?







5. CHECK THE HORN SWITCH INPUT FOR A SHORT TO GROUND

1. Connect: BCM (Body Control Module) C2280C.

2. Disconnect: Clockspring C218A.

Does the horn continue to sound?







6. CHECK THE CLOCKSPRING FOR A SHORT TO GROUND

1. Connect: Clockspring C218A.

2. WARNING: Turn the ignition OFF and wait one minute to deplete the backup power supply. Failure to follow this instruction may result in serious personal injury or death in the event of an accidental deployment.

Ignition OFF and wait one minute.

3. Remove the driver air bag module. REFER to Driver Air Bag Module. Driver Air Bag Module

4. Disconnect: Clockspring C218B.

Does the horn continue to sound?







7. CHECK THE HORN SWITCH

1. Connect: Clockspring C218B.

2. Disconnect: Horn Switch C217A.

Does the horn continue to sound?







8. CHECK THE STEERING WHEEL HARNESS FOR A SHORT TO GROUND

1. Connect: Horn Switch C217A.

2. Disconnect: Inline C260.

Does the horn continue to sound?







9. CHECK FOR CORRECT BCM (Body Control Module) OPERATION

1. Ignition OFF.

2. Disconnect and inspect the BCM (Body Control Module) connectors.

3. Repair:

- corrosion (install new connector or terminals- clean module pins)
- damaged or bent pins- install new terminals/pins
- pushed-out pins- install new pins as necessary

4. Reconnect the BCM (Body Control Module) connectors. Make sure they seat and latch correctly.

5. Operate the system and determine if the concern is still present.

Is the concern still present?