For concerns with the secondary air injection system on 2009 and later Volkswagen Jetta SportWagens equipped with the 2.5L engine, make sure that the combi-valve has been tested thoroughly. The combi-valve can be tested using the output diagnosis in address 01 0 engine electronics (ECM).

The following fault codes may be stored in the ECM:

P0491 (secondary air injection system Bank 1 insufficient flow)

P2431 (secondary air injection system air flow/pressure, Bank 1 sensor circuit)

P2432 (secondary air injection system air flow/pressure, Bank 1 sensor circuit low)

P2433 (secondary air injection system air flow/pressure, Bank 1 sensor circuit high intermittent)

Check that the combi-valve moves through the full range of motion on visual inspection with a mirror and light source, while running the output test with key-on-engine-off. Replace the valve if it does not complete the full range of motion during the test.