Inspection and Verification

Horn

Inspection and Verification

1. Verify the customer concern.

2. Visually inspect for obvious signs of mechanical or electrical damage.

Visual Inspection Chart:

3. If an obvious cause for an observed or reported concern is found, correct the cause (if possible) before proceeding to the next step.

4. NOTE: Make sure to use the latest scan tool software release.

Connect the scan tool to the Data Link Connector (DLC).

5. NOTE: The Vehicle Communication Module (VCM) LED prove-out confirms power and ground from the DLC are provided to the VCM.

If the scan tool does not communicate with the VCM:

- Check the VCM connection to the vehicle.

- Check the scan tool connection to the VCM.

- Refer to Information Bus, No Power To The Scan Tool, to diagnose no power to the scan tool.

6. If the scan tool does not communicate with the vehicle:
- Verify the ignition key is in the ON position.

- Verify the scan tool operation with a known good vehicle.

- Refer to Information Bus to diagnose no response from the PCM.

7. Carry out the network test.
- If the scan tool responds with no communication for one or more modules, refer to Information Bus.

- If the network test passes, verify the symptom. GO to Symptom Chart. Symptom Related Diagnostic Procedures