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. CHECK THE BCM (Body Control Module) HORN OUTPUT CIRCUIT FOR A SHORT TO VOLTAGE

1. Ignition OFF.

2. Disconnect: BCM (Body Control Module) C2280E.

3. Ignition ON.

Does the horn continue to sound?








2. ISOLATE THE BCM (Body Control Module)

1. Ignition OFF.

2. Connect: BCM (Body Control Module) C2280E.

3. Disconnect: BCM (Body Control Module) C2280B.

Does the horn continue to sound?








3. CHECK THE HORN SWITCH INPUT TO THE BCM (Body Control Module) CIRCUIT FOR A SHORT TO GROUND

1. Disconnect: SCCM (Steering Column Control Module) C2414A.

2. Connect: BCM (Body Control Module) C2280B.

Does the horn continue to sound?








4. ISOLATE THE STEERING WHEEL AND HARNESS

1. Connect: SCCM (Steering Column Control Module) C2414A.

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

3. Disconnect: Clockspring C218B.

4. Connect: Battery Ground Cable.

Does the horn continue to sound?








5. CHECK THE CLOCKSPRING FOR A SHORT TO GROUND

1. Remove the clockspring. REFER to Clockspring .

Does the horn continue to sound?








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

1. Disconnect and inspect all BCM (Body Control Module) connectors.

2. 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

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

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

Is the concern still present?








7. CHECK FOR CORRECT SCCM (Steering Column Control Module) OPERATION

1. Disconnect and inspect all SCCM (Steering Column Control Module) connectors.

2. 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

3. Reconnect the SCCM (Steering Column Control Module) connectors. Make sure they seat and latch correctly.

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

Is the concern still present?