Checking requirement
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.
- Vacuum hoses OK
- Disconnect vacuum hose to solenoid valve at line to brake servo. See SECONDARY AIR INJECTION SYSTEM COMPONENTS, REMOVING AND INSTALLING , item 2.
- Connect hand vacuum pump to vacuum hose.
- Disconnect pneumatic valve vacuum hose at valve. See SECONDARY AIR INJECTION SYSTEM COMPONENTS, REMOVING AND INSTALLING , item 1.
- Switch ignition OFF.
- Connect VAG1598/18 test box to ECM wiring harness connector.
- Switch ignition ON.
- Connect test box terminals 01 and 06 using jumper wires from VW1594 adaptor kit.
- Operate hand vacuum pump.
Vacuum must build up (valve closed).
If vacuum does not build up:
- Replace solenoid valve 2.
If vacuum builds up:
- Connect test box socket 50 to Ground using jumper wires from VW1594 connector test kit
Valve must open.
- Operate hand vacuum pump.
Vacuum must not build up (valve open).
If vacuum builds up:
- Disconnect 2 pin harness connector from solenoid valve.
- Connect VAG1527B LED tester to harness connector using jumper wires from VW1594 adaptor kit.
LED tester must light up.
If tester lights up (voltage supply OK):
- Replace solenoid valve.
If tester does not light up:
- Check wiring for open circuit between test box socket 50 and terminal 2 of 2-pin harness connector using wiring diagram.
Resistance: 1.5 ohms maximum
- Check wiring between central electric and solenoid valve harness connector (terminal 1) using wiring diagram.
- Connect 2-pin harness connector.
- Check DTC memory, then erase. See appropriate On Board Diagnostic (OBD) article.