DTC-based diagnosis

The diagnostic procedure is based on stored DTCs.

1. Use the method of exclusion to determine the faulty parts according to DTC setting conditions.

2. Check the data of relevant parts using a VDS and exclude possible faults one by one.

Symptom-based diagnosis (DTCs not stored)

The diagnostic procedure is based on fault symptoms.

1. Use the method of exclusion to determine the faulty parts according to fault symptoms. Check the relevant parts using a VDS and exclude possible faults one by one.

2. Check the data of relevant parts using a VDS and exclude possible faults one by one.

Step 1

Get the detailed information when an electrical fault occurs.

Step 2

1. Operate the affected system and conduct a road test if necessary.

2. Confirm the fault parameters.

3. If recurrence of the fault is impossible, refer to "Circuit simulation test".

Step 3

1. Collect appropriate diagnostic data, including:

a. system circuit diagram

b. schematic diagram of the system

c. corresponding chapters of the maintenance manual

d. other relevant information

2. Perform diagnosis according to the knowledge about system operation and the customer's feedback.

Step 4

1. Check the system for adhesion, loose connectors, damaged wiring harness or other faults.

2. Confirm the circuits and parts involved, and perform diagnosis according to the system circuit diagram and the wiring harness layout diagram.

Step 5

Repair the circuit and replace faulty parts if necessary.

Step 6

Operate the system in all modes and ensure that the system can work normally under all conditions. Make sure that no other new faults are caused by negligence during the diagnosis or maintenance.