Intake Air Switch-Over Valve -N335- Checking

Intake Air Switch-Over Valve -N335-, Checking
Via the Intake Air Switch-over valve, a flap in the air filter housing is activated.

Electrical testing of intake manifold changeover valve
- Disconnect connector from Intake Manifold Change-Over Valve -N156-.







- Perform a resistance measurement between the valve terminals using V.A.G 1526.
Specified value: 25 to 35 Ohms
- If specified value is not obtained.
- Replace Intake Air Switch-over valve -N335-.
- If specified value is obtained.
- Check voltage supply.

Checking voltage supply of intake air switchover valve







- Connect V.A.G 1527 voltage test lamp between connector terminal 2 and engine Ground (GND) using adapter cables from V.A.G 1594 connector test kit.
- Switch ignition on.

LED must light up.
- LED does not light up.
- Check fuse for intake air switch-over valve (relay- and fuse holder in instrument panel, right side).

If fuse is OK.
- Check wire connection from terminal 2 of connector for intake air switch-over valve via fuse to Motronic Engine Control Module (ECM) Power Supply Relay -J271- (relay carrier in E-box in plenum chamber) for open circuit/short circuit.

If voltage supply is OK, check wire connection.

Checking wire connection of intake air switch-over valve
- Connect V.A.G 1598/31 test box to wiring harness of Engine Control Module (ECM)
- Check the following wire connection for open circuit/short circuit:

Connector at wiring V.A.G 1598/31 test box or
harness, terminal Engine Control Module (ECM)
1 9

- If wire connection is OK, replace Engine Control Module (ECM) and generate readiness code again