The 4WD ECM controls the Pump Motor Pump (Actuator) to generating an oil pressure. The pressure engages a multiple disk clutch to transfer torque to the rear wheels. The torque to the rear wheels varies according to the pressure on the clutch.
If the 4WD ECM detects that there is an overcurrent in the Motor Pump circuit, it sets P1820 and lets a warning lamp turn on.
Item
Detecting Condition
Possible cause
DTC Strategy
Monitoring current in the motor pump circuit
Poor connection
Open or short in the circuit
Internal error in the coupling
Enable conditions
Engine " ON "
Threshold value
The current in the motor driving circuit > 25A
Detecting time
Immediately
Fail Safe
Prohibition for 4WD control