Operation CHARM: Car repair manuals for everyone.

With Generic Scan Tool



Combination Valves For Secondary Air Injection (air) System, Checking Function And For Proper Seal

Recommended special tools and equipment







- VAG1390 Hand Vacuum Pump

Test requirements:
- No leaks in vacuum lines or hose connections.
- Vacuum lines not clogged.

Test sequence







- Remove rear engine cover (arrows).







- Remove bolts for holding plate for solenoid valves (arrows).
- Lift up holding plate and disconnect vacuum hose of combination valve to be checked from Y-piece.
- Connect e.g. V.A.G 1390 hand vacuum pump to vacuum hose of combination valve to be checked.







- For vehicles with auxiliary heater, remove bolts (arrows) for exhaust pipe of parking heater/auxiliary heater on noise insulation.







- Loosen mounting parts -1- to -4- and remove noise insulation.







- Disconnect pressure hose -1- at Secondary Air Injection (AIR) pump motor and blow air in with light pressure (do not use pressurized air).
- Both combination valves must be closed, it must not be possible to blow through hose.
- Operate hand vacuum pump.
- The respective combination valve must open, it must be possible to blow through

If the respective combination valve does not open:
- Replace combination valve.

Final procedures
After repair work, the following work steps must be performed in the mentioned sequence:
1 - Check DTC memory, Diagnostic mode 3 - Check DTC memory. Diagnostic Mode 3: Check DTC Memory
2 - Erase DTC memory, diagnostic mode 4 - Reset/erase diagnostic data. Diagnostic Mode 4: Reset/Erase Diagnostic Data
3 - Generate readiness code. Readiness Code, Generating

- End diagnosis and switch ignition off.