Air Injection Pump: Testing and Inspection

Secondary Air Injection Pump Motor, Checking

Special tools, testers and auxiliary items required

• Multimeter.

• Wiring diagram.

Test requirements

• The Secondary Air Injection (AIR) Pump Relay (-J299-) OK.

• The Motronic Engine Control Module (ECM) Power Supply Relay (J271) OK.

• Battery voltage at least 12.5 V.

• All electrical consumers switched off (radiator fan must NOT run during test).

• A/C switched off.

• The ignition switched off.

Test procedure

- Perform a preliminary check to verify the customers complaint. Refer to => [ Preliminary Check ] Preliminary Check.

Start diagnosis

- Raise the vehicle.

- Loosen the quick release fasteners - 1,2,3,4 - and remove the noise insulation panel.





- Disconnect the Secondary Air Injection (AIR) Pump Motor (-V101-) electrical harness connector - 3 -.





Checking voltage

- Crank the engine.

- Using a Multimeter, check the Secondary Air Injection (AIR) Pump Motor (-V101-) electrical harness connector terminals 1 to 2 for voltage.





- Switch the ignition off.

Specified value: battery voltage.

If the specified value was not obtained:

- Using a Multimeter, check the Secondary Air Injection (AIR) Pump Motor (-V101-) electrical harness connector terminal 2 to Ground (GND).





Specified value: battery voltage.

If the specified value was not obtained:

- Check the wiring connection from the Secondary Air Injection (AIR) Pump Relay (-J299-) socket 8/87 to the Secondary Air Injection (AIR) Pump Motor (-V101-) electrical harness connector terminal 2 for an open circuit or a short circuit.

- Check the wiring connections for damage, corrosion, lose or broken terminals.

- If necessary, repair the faulty wiring connection.

If the specified value was obtained:

Checking Ground (GND)

- Using a Multimeter, check the Secondary Air Injection (AIR) Pump Motor (-V101-) electrical harness connector terminal 1 to Ground (GND) for resistance.





Specified value: 1.5 ohms Max.

If the specification was not obtained:

- Check the wiring from the Secondary Air Injection (AIR) Pump Motor (-V101-) electrical harness connector terminal 1 to the Ground connection on the right A" pillar for a short circuit to each other, Battery (+), or an open circuit.

- Check the electrical harness connector for damage, corrosion, lose or broken terminals.

- If necessary, repair the faulty wiring connection.

If no malfunction is found in the wiring and voltage supply was OK:

- Replace the Secondary Air Injection (AIR) Pump Motor (-V101-).

Assembly is performed in the reverse order of removal.

Final procedures

After repair work, the following work steps must be performed in the following sequence:

1. Check the DTC memory. Refer to => [ Diagnostic Mode 03 - Read DTC Memory ] Diagnostic Mode 03 - Read DTC Memory.

2. If necessary, erase the DTC memory. Refer to => [ Diagnostic Mode 04 - Erase DTC Memory ] Diagnostic Mode 04 - Erase DTC Memory.

3. If the DTC memory was erased, generate readiness code. Refer to => [ Readiness Code ] Monitors, Trips, Drive Cycles and Readiness Codes.

- End of diagnosis.