Start Control Module (SCU)

Courtesy of VOLVO CARS CORPORATION

The start control module (SCU) with start button and card holder is the unit which is used by the driver to start the vehicle. See also DESIGN AND FUNCTION, IMMOBILIZER/START INHIBITION .

Start control module (SCU) activate the voltage supply to certain functions in the engine control module (ECM) via fuses in the front relay/fuse box and central electronic module (CEM). Start control module (SCU) supplies the engine control module (ECM) with a start signal.

Start control module (SCU) transmits a high signal (U_bat ) to engine control module (ECM) when start control module (SCU) is in position III.

The engine control module (ECM) will activate the starter motor relay. In turn the relay activates the starter motor. Also refer to: FUNCTION  

Start control module (SCU) is supplied with voltage from the fuse in the front relay / fuse box.

The central electronic module (CEM) can diagnose the start control module (SCU).