Diagnostic Procedure

STEP 1. Scan tool (M.U.T.-III) CAN bus diagnostics
Use Scan tool (M.U.T.-III) to diagnose the CAN bus lines.

Q: Is the check result normal?

YES : Go to Step 2.

NO : Repair the CAN bus line (Refer to - Diagnosis, CAN BUS DIAGNOSTICS TABLE ). On completion, go to Step 2.
STEP 2. Voltage measurement at the AWC-ECU connector
1. Disconnect the AWC-ECU connector.
2. Turn the ignition switch to the ON position.
3. Measure the voltage between the AWC-ECU wiring harness side connector terminals BATT, IG1 (Ignition switch "ON") and the body ground.
  OK: System voltage
Q: Is the check result normal?

YES : Go to Step 3.

NO : Repair the connector(s) or terminal(s) or wiring harness.
STEP 3. Resistance measurement at the AWC-ECU connector
1. Disconnect the AWC-ECU connector.
2. Measure the resistance between the AWC-ECU wiring harness side connector terminals No. GND1 and the body ground.
  OK: Continuity exists (2 Ω or less)
Q: Is the check result normal?

YES : Go to Step 4.

NO : Repair the connector(s) or terminal(s) or wiring harness.
STEP 4. Retest the system.
Q: Does the malfunction occur again?

YES : Replace AWC-ECU (Refer to AWC-ECU <VEHICLES WITH S-AWC> ). Then go to Step 5.

NO : The trouble can be an intermittent malfunction (Refer to - How to Use Troubleshooting/HOW TO COPE WITH INTERMITTENT MALFUNCTIONS ).
STEP 5. Retest the system.
Q: Does the malfunction occur again?

YES : Diagnose again from Step 1.

NO : This diagnosis is complete.