Passat L4-1984cc 2.0L DOHC (1991)
Canister Purge Solenoid: Testing and Inspection
Frequency Valve And On/Off Solenoid Valve
The on off valve is located under the intake boot near the mixture control unit. It is a solenoid controlled by the Motronic control unit. It works in
conjunction with the frequency valve to control the flow of fuel vapors to and from the charcoal canister to the intake manifold.
TESTING
1.
Disconnect the black harness connector from the valve.
2.
Remove the vacuum hoses from the valve and blow through it.
Air should not pass through valve.
3.
Apply system voltage to the valve connectors and blow through it. Air should pass through valve.
4.
If the valve fails either test it should be replaced.