General Information

4WD Control

P1780 Engine Size Failure - General Information

Component Location





General Description

Vehicle uses 2WD (2 wheel drive) for driving at normal speed, but sometimes it uses 4WD ECM (= TCCU : Transfer Case Control Unit) according to driving condition. (cornering or acceleration)
EMC (=Electric Magnetic Clutch) distributes proper torque to front wheel by controling amount of current inside EMC coil.
That time power pressing the multi plate clutch by apply cam is changed by a rate of EMC duty. after multi plate clutch start slip the force for acceleration at front/rear wheel is controlled at a range of 100:0 - 50 : 50.
ITM system has 4WD-LOCK function that can make driving force to 50:50 by compulsion according to driver's intention.

DTC Description

If the EMC is rapidly heated by an excessive tire's slip, the 4WD ECM sets this DTC in order to protect the clutch from damage.

DTC Detecting Condition





Diagnostic Circuit Diagram










Signal Waveform & Data




Fig.1) CAN Signal : high & low