4WD Control System Check

4WD Control System Check
Refer to the following items for the details of each step.

Step 1-9:

Step 10-11:

Detail of 4WD Control System Check

Step 1. Customer complaint analysis
Record details of the problem (failure, complaint) and how it occurred as described by the customer.
For this purpose, use of such a questionnaire form as shown in the following will facilitate collecting information to the point required for proper analysis and diagnosis.

Customer questionnaire (Example)





NOTE: The form is a standard sample. It should be modified according to conditions characteristic of each market.

Step 2. DTC check, record and clearance
First, check DTC and pending DTC. If DTC exists, print or write down DTC and then clear malfunction DTC(s). Malfunction DTC indicates malfunction in the system but it is not possible to know from it whether the malfunction is occurring now or it occurred in the past and normal condition has been restored. In order to know that, check symptom in question according to Step 5 and then recheck DTC according to Step 6.
Diagnosing a trouble based on the DTC in this step only or failure to clear the DTC in this step may result in an faulty diagnosis, trouble diagnosis of a normal circuit or difficulty in troubleshooting which is otherwise unnecessary.

Step 3 and 4. Visual inspection
As a preliminary step, be sure to perform visual check of the items that support proper function of the 4WD control system.

Step 5. Trouble symptom confirmation
Check trouble symptoms based on information obtained in Step 1. Customer complaint analysis and Step 2. DTC check, record and clearance.
Also, reconfirm DTC according to DTC Confirmation Procedure described in each DTC flow.

Step 6 and 7. Rechecking and record of DTC
Recheck for DTC.

Step 8. 4WD control symptom diagnosis
Check the parts of the system suspected as a possible cause.

Step 9. Troubleshooting for DTC
Based on the DTC indicated in Step 6 / 7 and referring to applicable DTC flow, locate the cause of the trouble, namely in a sensor, switch, wire harness, connector, coupling assembly, 4WD control module or other part and repair or replace faulty parts.

Step 10. Check for intermittent problem
Check parts where an intermittent trouble is easy to occur (e.g. wire harness, connector, etc.), and related circuit of DTC recorded in Step 2.

Step 11. Final confirmation test
Confirm that the problem symptom has gone and the vehicle is free from any abnormal conditions. If what has been repaired is related to the malfunction DTC, clear the DTC once and check to ensure that no malfunction DTC is indicated.