Measurements and analysis with the VAS 5051
Activated charcoal filter solenoid valve N80
The activated charcoal filter solenoid valve is a valve in the tank venting system. The solenoid valve closes the tank venting system downstream of the activated charcoal filter and is only opened electrically by the engine control unit. The solenoid valve is activated periodically by the engine control unit according to evaluation of the lambda probe, the throttle valve sender and the coolant temperature sender.
The adjacent circuit diagram shows the electrical connections of the activated charcoal filter sole- noid valve on the 1.8 l/92 kW petrol engine.
The electric signal for subsequent analysis by the DSO is measured at the following contacts:
DSO 1 (+)
DSO 1 ()
Contact 2 (signal) Contact 1 (positive)
The solenoid valve control signal can be dis- played as a curve by intermediate connection of an adapter lead from the V.A.G. 1594A test set into the lead to the activated charcoal filter sole- noid valve with the DSO measuring lead of the VAS 5051 tester connected.
The individual adapter leads are described on page 30.
Faults can be detected compared to a defined, preset measurement.
The following curve is obtained: