XC90 AWD V8-4.4L VIN 85 B8444S (2005)
The function of the injectors is to spray fuel into the cylinders in the correct spray patterns. This happens sequentially.
The injectors are located under the intake manifold.
The engine control module (ECM) controls the injectors by grounding the valves in pulses.
The injectors can be diagnosed by the engine control module (ECM) and can be activated.
The ignition coils supply the spark plugs with high voltage to produce sparks. The engine control module (ECM) controls the ignition coils so that sparks
are generated at the correct time. The signal reconnects to the engine control module (ECM) so that diagnostics can be carried out.
Each ignition coil has an integrated power stage.
The ignition coils are in the sparkplug wells above each spark plug.
The engine control module (ECM) can diagnose the ignition coils.
Camshaft reset valve (Continuous variable valve timing (CVVT))
The camshaft reset valve controls the oil flow to the CVVT unit (camshaft pulley).
The valve consists of an electro-magnetic valve with a spring-loaded piston. There are slits in the piston which channel the engine lubricating oil to the
CVVT unit by moving the piston in the reset valve. The continuous variable valve timing (CVVT) unit turns the camshaft (the camshaft timing changes).
The direction in which the camshaft turns depends on the chamber in the CVVT unit which is supplied with oil (pressure). See also: Function, B8444S