XC70 AWD L6-3.2L VIN 98 B6324S (2009)
Engine Control Module: Description and Operation
Design
Part 1
Design
Start control module (SCU)
The start control module (SCU), with its starter button, is the unit that the driver uses to start the vehicle. Also see Design and Function,
Immobilizer/start inhibition.
The start control module (SCU) activates the power supply to certain functions in the engine control module (ECM) via fuses in the front integrated
relay/fusebox and central electronic module (CEM). The start control module (SCU) also supplies the engine control module (ECM) with start signals.
The start control module (SCU) transmits a high signal (Ubat) to the engine control module (ECM) when the 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. See also: Function See: Powertrain
Management/Computers and Control Systems/Description and Operation/Engine Control Module (ECM)/Function
The start control module (SCU) is supplied with power from the fuse in the front integrated relay/fusebox.
The central electronic module (CEM) can diagnose the start control module (SCU).
Transmission control module (TCM)
The engine control module (ECM) uses a directly connected signal from the transmission control module (TCM) in the start function (activating the
starter motor).
Immobilizer
See Design and Function, Immobilizer/start inhibition.
Alternator control module (ACM)
See Design and Function, Alternator.
Engine speed (rpm) sensor