How To Proceed With Troubleshooting

UF1AE TRANSFER: FOUR WHEEL DRIVE CONTROL SYSTEM: HOW TO PROCEED WITH TROUBLESHOOTING

HINT
The Techstream can be used in steps 3, 4, 5, 7 and 11.

1. VEHICLE BROUGHT TO WORKSHOP

NEXT -- Continue to next step.

2. CUSTOMER PROBLEM ANALYSIS

(a) Confirm problem symptoms.

NEXT -- Continue to next step.

3. CHECK MULTIPLEX COMMUNICATION SYSTEM

(a) Check for DTCs Reading and Clearing Diagnostic Trouble Codes.

HINT
The 4WD control ECU sends the signals from the indicator light to the gateway ECU via CAN communication, and the gateway ECU sends the signals to the combination meter assembly via the multiplex communication system (BEAN).

Result:





B -- CHECK MULTIPLEX COMMUNICATION CIRCUIT
A -- Continue to next step.

4. CHECK CAN COMMUNICATION SYSTEM

(a) Check for DTCs Reading and Clearing Diagnostic Trouble Codes.

HINT
The ECU of this system is connected to the CAN communication system.

Therefore before starting troubleshooting, make sure to check that there is no trouble in the CAN communication system.

Result:





B -- CHECK CAN COMMUNICATION CIRCUIT
A -- Continue to next step.

5. CHECK DTC

(a) Check for DTCs Reading and Clearing Diagnostic Trouble Codes.

(1) Record the DTCs.

(b) Clear the DTCs.

(c) Recheck for DTCs.

(1) Reproduce the malfunction and check if the DTCs are output again.

Result:





B -- GO TO STEP 10

C -- SYMPTOM SIMULATION
A -- Continue to next step.

6. DTC CHART

(a) Go to "DIAGNOSTIC TROUBLE CODE CHART" Transfer Case Four Wheel Drive Control System - UF1AE.

NEXT -- Continue to next step.

7. CIRCUIT INSPECTION

NEXT -- Continue to next step.

8. REPAIR

NEXT -- Continue to next step.

9. CONFIRMATION TEST

NEXT -- END

10. HYDRAULIC TEST

(a) Perform hydraulic test Hydraulic Test.

NG -- REPAIR HYDRAULIC CIRCUIT
OK -- Continue to next step.

11. PROBLEM SYMPTOMS TABLE

(a) Go to "PROBLEM SYMPTOMS TABLE" Symptom Related Diagnostic Procedures.

NEXT -- Continue to next step.

12. CIRCUIT INSPECTION

NEXT -- Continue to next step.

13. REPAIR

NEXT -- Continue to next step.

14. CONFIRMATION TEST

NEXT -- END