Active Torque Control 4WD System

MF1A TRANSFER / 4WD / AWD: ACTIVE TORQUE CONTROL 4WD SYSTEM: C1241/94: Low Power Supply Voltage
C1241/94 - Low Power Supply Voltage

DESCRIPTION

If a malfunction in the power source circuit occurs, or a malfunction in communication with the skid control ECU or in a speed sensor occurs, the 4WD control ECU will prohibit operations by the fail-safe function.





WIRING DIAGRAM





INSPECTION PROCEDURE

HINT
Check the condition of each related circuit connector before troubleshooting Electronic Circuit Inspection Procedure.

PROCEDURE

1. CHECK FOR DTC

(a) Clear the DTC Reading and Clearing Diagnostic Trouble Codes.

(b) Turn the ignition switch to ON and check that no CAN communication system DTC is output.

(c) Start the engine.

(d) Drive the vehicle, accelerate to a speed of 3 km/h (2 mph) or more, and check that no speed sensor DTC (brake control system DTC) is output Vehicle Stability Control System.

Result:





B -- REPAIR CIRCUIT INDICATOR BY OUTPUT CODE (CAN COMMUNICATION SYSTEM) How to Proceed With Troubleshooting

C -- REPAIR CIRCUIT INDICATOR BY OUTPUT CODE (BRAKE CONTROL SYSTEM) Vehicle Stability Control System
A -- Continue to next step.

2. INSPECT FUSE (ECU-IG NO. 1)

(a) Remove the ECU-IG NO. 1 fuse from the instrument junction block

(b) Measure the resistance of the fuse.

Standard Resistance:





HINT
Check for short circuits in all harnesses and connector connected to the ECU-IG NO. 1 fuse Service Precautions.

NG -- REPLACE FUSE
OK -- Continue to next step.

3. CHECK WIRE HARNESS (4WD CONTROL ECU - BATTERY)





(a) Disconnect the ECU connector.

(b) Measure the voltage of the wire harness side connector.

Standard Voltage:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

4. CHECK WIRE HARNESS (4WD CONTROL ECU - BODY GROUND)





(a) Disconnect the ECU connector.

(b) Measure the resistance of the wire harness side connector.

Standard Resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

5. RECONFIRM DTC

(a) Clear the DTC Reading and Clearing Diagnostic Trouble Codes.

(b) Start the engine.

(c) Drive the vehicle, accelerate to a speed of 3 km/h (2 mph or more, and check if the same DTC is output.

Result:





HINT
Reinstall the sensor, connectors, etc. and restore the vehicle to its prior condition before rechecking DTCs.

B -- END

A -- REPLACE 4WD CONTROL ECU Removal