Passat L4-1984cc 2.0L DOHC (1991)
Component Location
TESTING
1.
Disconnect the gray harness connector from the valve.
Fig. 42 Evaporative Emissions Control (EEC) System Frequency Valve, 16V
2.
Remove the vacuum hoses from the valve and blow through it.
Air should pass through valve.
3.
Apply system voltage to the valve connectors and blow through it. Air should not pass through valve.
4.
If the valve fails either test it should be replaced.