Inspection Procedure
1: M.U.T.-III cannot Communicate with the Electronically Controller 4WD System.
COMMENTS ON TROUBLE SYMPTOM
If M.U.T.-III cannot communicate with the electronically controlled 4WD system, the CAN
bus lines may have a problem. If the electronically controller 4WD system is not in operation
(in case of no 4WD operation), the 4WD-ECU power supply circuit system or 4WD-ECU may have a
problem.
PROBABLE CAUSES
Damaged wiring harness and connectors
4WD-ECU malfunction
DIAGNOSIS PROCEDURE
STEP 1. M.U.T.-III CAN bus diagnostics
Use M.U.T.-III to diagnose the CAN bus lines.
Q.
Is the check result normal?
Go to Step 2.
Repair the CAN bus line (Refer to GROUP 54C - Troubleshooting/CAN
Bus Diagnostics Table ). On completion, go to Step 2.
STEP 2. Voltage measurement at the 4WD-ECU connector
(1)Disconnect the 4WD-ECU connector.
(2)Turn the ignition switch to the ON position.
(3)Measure the voltage between the 4WD-ECU wiring harness side connector terminals
BATT, IG1 (Ignition switch "ON") and the body earth. OK: System voltage
Q.
Is the check result normal?
Go to Step 3.
Repair the connector(s) or terminal(s) or wiring harness.
STEP 3. Resistance measurement at the 4WD-ECU connector
(1)Disconnect the 4WD-ECU connector.
(2)Measure the resistance between the 4WD-ECU wiring harness side connector terminals
No. GND1 and the body earth. OK: Continuity exists (2 Ω or less)
Q.
Is the check result normal?
Go to Step 4.
Repair the connector(s) or terminal(s) or wiring harness.
STEP 4. Retest the system.
Q.
Does the malfunction occur again?
Replace 4WD-ECU (Refer to ). Then go to Step 5
.
The trouble can be an intermittent malfunction (Refer to GROUP 00 - How
to Use Troubleshooting/How to Cope with Intermittent Malfunctions ).
Go to Step 2.
Repair the CAN bus line (Refer to GROUP 54C - Troubleshooting/CAN
Bus Diagnostics Table 
). On completion, go to Step 2.