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 .

(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 ABS (Antilock Brake System).

Result:





C -- REPAIR CIRCUIT INDICATOR BY OUTPUT CODE (BRAKE CONTROL SYSTEM) ABS (Antilock Brake System)

B -- REPAIR CIRCUIT INDICATOR BY OUTPUT CODE (CAN COMMUNICATION SYSTEM) CAN Communication System
A -- Continue to next step.

2. INSPECT FUSE (ECU-IG)

(a) Remove the ECU-IG1 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-IG1 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 .

(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