Air Injection Pump: Testing and Inspection

Diagnostic Procedures

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- ) fuse 27 in Fuse Box B is OK.

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

- Disconnect the secondary air injection hose.

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





Checking voltage

- Start the engine.

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





Specified value: battery voltage.

- Switch the ignition off.

If the specified value was Not obtained:

- Switch the ignition on

- 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 2 (relay terminal 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, loose or broken terminals or an open fuse. Refer to the wiring diagram.

- If necessary, repair the faulty wiring connection, replace fuse if needed.

If the wiring has no fault, the fuse is not open and voltage is Not present:

Replace the Secondary Air Injection (AIR) Pump Relay (-J299-)

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 specified value was Not obtained:

- Check the wiring for an open or high resistance.

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

- If necessary, repair the faulty wiring connection.

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

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

- Erase the DTC memory. Refer to => [ Diagnostic Mode 04 - Erase DTC Memory ] Scan Tool Testing and Procedures.

- Perform a road test to verify repair.

Final procedures

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

1. Check the DTC memory. Refer to => [ Diagnostic Mode 03 - Read DTC Memory ] Scan Tool Testing and Procedures.

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

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