Secondary Air Injection Sensor 1, Checking

Secondary Air Injection Sensor 1, Checking

Special tools, testers and auxiliary items required

• multimeter

• Wiring diagram.

Test requirements

• The Motronic Engine Control Module (ECM) (J623) fuses OK.

• The fuel filter OK.

• The battery voltage at least 12.5 V.

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

• A/C switched off.

• The fuel tank at least 1/4 filled.

• The ignition switched off.

Test procedure

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

Start diagnosis

- Remove the engine cover with air filter

Checking voltage

- Disconnect the Secondary Air Injection Sensor 1 (G609) electrical harness connector.

- Switch the ignition on.

- Using a multimeter, check the Secondary Air Injection Sensor 1 (G609) electrical harness connector terminals for voltage.





- Switch the ignition off.

If the specified value was obtained:

- Replace the Secondary Air Injection Sensor 1 (G609)
If the specified value was not obtained:

Checking wiring connections

If the manufacturers test box is being used, perform the following step.

- Install the test box.

If the manufacturers test box is not being used, perform the following step.

- Remove the Motronic Engine Control Module (ECM) (J623). Refer to => [ Motronic Engine Control Module, Replacing ] Motronic Engine Control Module, Replacing.

- Using a multimeter, check the Secondary Air Injection Sensor 1 (G609) electrical harness connector terminals to the Motronic Engine Control Module (ECM) (J623) electrical harness connector T60 terminals for an open circuit according to the wiring diagram.





Specified value: 1.5 ohms Max.

If the specification is not obtained:

- Check the wiring for an open, high resistance or short to ground.

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

- If necessary, repair the faulty wiring connection.

If no malfunction is detected in the wiring:

- Replace the Motronic Engine Control Module (ECM) (J623). Refer to => [ Motronic Engine Control Module, Replacing ] Motronic Engine Control Module, Replacing.

- Install the engine cover with air filter

Final procedures

After the 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 ] Readiness Code.