Test sequence

WARNING: This page does not describe the selected car, but rather 25 other vehicles, including the 2002 Volkswagen Cabrio, 2001 Volkswagen Cabrio, 2000 Volkswagen Cabrio, 1999 Volkswagen Jetta, and 1999 Volkswagen Golf. However, it is still accessible from the selected car via links, so may be relevant.

Disconnect vacuum hose from secondary air injection solenoid valve.
Attach US 8026 hand vacuum pump to vacuum hose.
Disconnect pressure line from pneumatic valve.

NOTE: Do not use compressed air for the following check.

Connect auxiliary hose to pneumatic valve and blow into it.
Pneumatic valve must be closed.
Operate hand vacuum pump.
Valve must open and operate smoothly (without sticking).
Replace valve if necessary.