U1802

U1802-08-LIN BUS - GENERAL SIGNAL FAILURE

For a complete wiring diagram, refer to the Wiring Information.

Theory of Operation

The Body Control Module (BCM) is the Local Interface Network (LIN) master for the Power Top Control Module. The Power Top Control Module performs a series of self-diagnostics as well as monitoring the Power Top Motor and Power Top Switch. As the LIN master, the BCM receives a set of required messages from the Power Top Control Module indicating the status of the components monitored by the Power Top Control Module.

- When Monitored:
Continuously.

- Set Condition:
When the BCM detects that the LIN Bus is shorted to ground or battery voltage.





1. CHECK FOR AN ACTIVE DTC
1. Turn the ignition on.
2. With the scan tool, clear the DTCs.
3. Cycle the ignition off and on.
4. Wait 10 seconds.
5. With the scan tool, read DTCs.

Does the scan tool display this DTC as active?

Yes

- Go To 2

No

- Test complete, the condition or conditions that originally set this DTC are not present at this time. Using the wiring diagrams as a guide, check all related splices and connectors for signs of water intrusion, corrosion, pushed out or bent terminals, and correct pin tension.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

2. CHECK THE (D401) BCM LIN 1 BUS CIRCUIT FOR A SHORT TO VOLTAGE
1. Turn the ignition off.
2. Disconnect the Power Top Control Module harness connector.
3. Disconnect the BCM C2 harness connector.
4. Turn the ignition on.
5. Measure the voltage between ground and the (D401) BCM LIN 1 Bus circuit.

Is there any voltage present?

Yes

- Repair the short to voltage on the (D401) BCM LIN 1 Bus circuit.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

No

- Go To 3

3. CHECK THE (D401) BCM LIN 1 BUS CIRCUIT FOR A SHORT TO GROUND
1. Turn the ignition off.
2. Measure the resistance between ground and the (D401) BCM LIN 1 Bus circuit.

Is the resistance above 10k Ohms?

Yes

- Replace the Power Top Control Module. Full Open Retractable Roof Module - Removal.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

No

- Repair the short to ground on the (D401) BCM LIN 1 Bus circuit.
- Perform the BODY VERIFICATION TEST. Body Verification Test.