Integrated Motor Assist System: Insight

The Integrated Motor Assist (IMA) system is the term given the highly efficient combination of gasoline engine and electric motor. The IMA system uses the engine as the main power source and the electric motor as a supplemental power source.

The electric motor is a DC brushless type located between the engine and the transaxle. The high voltage DC circuits, such as, battery module, junction board and Power Control Unit, are contained in the Intelligent Power Unit (IPU). The IPU is located in rear of vehicle for efficient packaging and safety.

The Motor Control Module controls the motor to provide the proper amount of assist and regenerative power needed to prevent excessive battery drain and battery overcharging.

To conserve fuel and minimize tailpipe emissions, IMA is equipped with an Auto-Stop System activated by the PCM to stop the engine when the vehicle comes to a stop. When Auto-Stop is engaged, AUTO-STOP indicator light on instrument panel will either blink or remain illuminated as a warning. Auto-Stop function will be over-ridden and engine will restart when transaxle is shifted to any position other than Neutral with clutch pedal engaged or when accelerator pedal is depressed with transaxle in Neutral and clutch pedal engaged.

The Auto-Stop function will NOT be engaged if transaxle is in 1st or Reverse, AUTO or DEF modes of climate control unit are engaged, passenger compartment temperature has not yet stabilized at desired set temperature, engine coolant temperature is 122°F (50°C) or lower, 2 minutes after engine start, low battery charge, high electrical load on 12-volt system, accelerator pedal is depressed, or a defective Auto-Stop component is identified.