SAAB WIS ONLINE

Control valve, swirl throttle

Control valve, swirl throttle





The task of the charge air control valve is to convert electronic instructions from the PSG 16 control module to regulate a vacuum that can affect the diaphragm in the swirl throttle converter. The vacuum comes from the engine's vacuum pump, which always produces a predetermined underpressure.

Control valve pin 2 is connected to control module pin M43 and control valve pin 1 is connected to B+ from fuse 16B.

The control valve is grounded with a PWM pulse at 140 Hz through control module pin M43. The stroke relationship determines the size of the vacuum in the hose to the swirl throttle converter and thus controls the position of the swirl throttle.

Diagnosis

If the control module registers that the control valve circuit is open, P0660 will be generated.

If the control module output is short-circuited to B+, diagnostic trouble code P0662 will be generated.

If the control module output is short-circuited to ground, diagnostic trouble code P0661 will be generated.


System reaction to a fault

• If the swirl throttle remains closed, engine power will reduce at engine speeds over 3500 rpm. This is due to low air mass/combustion and an extended increased fuel consumption.