XC90 FWD L6-3.2L VIN 98 B6324S (2007)
Controlling the generator
The engine control module (ECM) (4/46) regulates the charge voltage of the alternator (GEN) (6/26) (via LIN communication) when requested by the
central electronic module (CEM) (4/56) (via CAN communication).
The engine control module (ECM) can change the requested charging voltage from the central electronic module (CEM) in order to adapt it to certain
operating conditions such as starting, idling or high engine loads.
The value of requested charge voltage from the engine control module (ECM) and the charge current of the generator can be read off.
The alternator control module (ACM) (6/26) transmits information to the engine control module (ECM) regarding any faults). The diagnostic trouble
codes (DTCs) are stored in the engine control module (ECM) in the event of a fault. In the event of certain faults, information about these faults is also
transmitted to the central electronic module (CEM).
For additional information on regulating the alternator, see Design and Function, Alternator and Design and Function, central electronic module (CEM).
Variable intake system
Today's modern car engines often utilize systems with variable length of the intake manifolds.
In older engines with fixed lengths, the length had to be adapted to a certain specific engine speed range.
Today's system gives greater flexibility as well as additional torque without any costs in the form of, e.g., fuel consumption or emissions.
In the variable intake system, there are two actuators with associated throttles to change the length of the intake manifolds. These are:
Actuator variable intake manifold, upper (6/139)
Actuator variable intake manifold, lower (6/140)
The primary throttle is activated at engine speed over approx. 4800 rpm and the secondary throttle is activated between approx. 3800 rpm and 4800 rpm
(applies at + 20° C).
Different throttle combinations:
Position 1: Both throttles are closed at engine speeds lower than approx. 3800 rpm.
Position 2: The secondary throttle opens at approx. 3800 rpm and this shortens the length some more.
Position 3: Both throttles are fully open to minimize the length at higher engine speeds (over 4800 rpm).
The valve for variable intake is controlled by the engine control module (ECM) (4/46).
The actuators for variable intake function can be activated and the function for variable intake can be diagnosed by the engine control module (ECM).
Variable camshaft profile (CPS)