Checking Secondary Air Injection (AIR) Pump Relay Power Supply

Checking secondary air injection (AIR) pump relay power supply
- Switch ignition off.





- Remove plenum chamber cover rubber seal in direction of (arrow).
- Remove plenum chamber cover -1- to front.





- Remove cover for electronics box in plenum chamber (arrows).





- Disconnect secondary air injection (AIR) pump relay (position 2).








- Connect multimeter for voltage measurement as follows.
^ Specification: approximately battery voltage

If reading does not match specification:
- Perform the following checks marked with a dot.





^ Check fuses 130 (50 A) in plenum chamber electronics box, position 7.
^ Use wiring diagram to check for open circuit in wiring from battery + (terminal 30) via fuse S 130 to secondary air injection (AIR) pump relay -J299- (in 3-position relay carrier in plenum chamber electronics box, position 2).
- Use wiring diagram to eliminate open circuit in wiring.





- Connect multimeter for voltage measurement as follows.
- Briefly operate starter.





^ Specification: approximately battery voltage

If reading does not match specification:
- Perform the following checks marked with a dot.





^ Check fuse S234 (in fuse box, position 34).
^ Use wiring diagram to check for open circuit in wiring from secondary air injection (AIR) pump relay -J299- (in 3-position relay carrier in plenum chamber electronics box) via fuse S234 (in fuse box, position 34) to fuel pump relay.
- Use wiring diagram to eliminate open circuit in wiring.

Checking actuation of secondary air injection (AIR) pump relay
- Switch ignition off.
- Disconnect secondary air injection (AIR) pump relay.








- Connect voltage tester V.A.G 1527 B as follows.





Indicated on VAS 5051:
- From list -1- select diagnostic function "03- Final control diagnosis".
- Keep touching > key, until the secondary air injection (AIR) solenoid valve -J299- is activated.
^ LED must flash
- Terminate function "03- Final control diagnosis" by touching < key.
- Switch ignition off.

If LED does not flash:





- Connect test box V.A.G. 1598/31 to wiring harness connectors. Actual engine control module is not to be connected. Connect ground clip of test box to ground (not shown in Fig.).

CAUTION: So as not to destroy electronic components, select required measuring range before connecting test leads and observe test conditions.








- Check for open circuit and short to ground/positive in the following wiring.
- Use wiring diagram to eliminate open circuit in wiring/short circuit.

If no fault is found:
- Replace secondary air injection (AIR) pump relay -J299-.

Checking power supply for secondary air injection (AIR) pump motor





- Unfasten quick-release fasteners -1- and -2- and detach front noise insulation. Leave rear noise insulation in position.





- Disconnect connector -1- at secondary air injection (AIR) pump motor V1 01 _.





- Connect voltage tester V.A.G. 1527 B between contacts -1- and -2-.
^ Vehicle diagnostic, testing and information system VAS 5051 connected; vehicle self-diagnosis and vehicle system "01- Engine electronics" selected. Ignition must be on.

Indicated on VAS 5051:





- From list -1- select diagnostic function "03- Final control diagnosis".
- Keep touching > key, until the secondary air injection (AIR) solenoid valve -J299- is activated.
^ LED must flash
- Terminate function "03- Final control diagnosis" by touching < key.

If LED does not flash:
- Perform the following checks marked with a dot.
^ Use wiring diagram to check for open circuit in wiring from contact 2 of connector to secondary air injection (AIR) pump relay J299- (in relay carrier in plenum chamber electronics box, position 2).
^ Use wiring diagram to check for open circuit in wiring from contact 1 of connector to ground.
- Use wiring diagram to eliminate open circuit in wiring.
If no fault is found:
- Replace secondary air pump.