Secondary Air Injection Solenoid Valve 2, Checking

Secondary Air Injection Solenoid Valve 2, Checking

Special tools, testers and auxiliary items required

• Multimeter.

• Wiring diagram.

Test requirements

• The Secondary Air Injection (AIR) Solenoid Valve 2 (N320) fuse OK.

• The Engine Component Power Supply Relay (J757) 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

- Remove the engine covers. Refer to the appropriate service manual.






- Disconnect the Secondary Air Injection (AIR) Solenoid Valve 2 (N320) electrical harness connector - 3 -.






Checking internal resistance

- Using a Multimeter, check the Secondary Air Injection (AIR) Solenoid Valve 2 (N320) terminals 1 to 2 for resistance.

Specified value: 25 to 35 ohms (at approx. 20° C)

If the specified value was Not obtained:

- Replace the Secondary Air Injection (AIR) Solenoid Valve 2 (N320) : Refer to appropriate service manual.

- Go to Final procedures

If the specified value was obtained:

Checking voltage supply

Switch the ignition ON.

- Using a Multimeter, check the Secondary Air Injection (AIR) Solenoid Valve 2 (N320) electrical connector terminal 1 to Ground (GND) for voltage.






Specified value: Battery voltage.

Switch the ignition OFF.

If the specified value was Not obtained:

- Check the wiring from the Secondary Air Injection (AIR) Solenoid Valve 2 (N320) electrical connector terminal 1 to Fuse SA16 (on fuse panel A) for an open or short circuit.

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

- If necessary, repair the faulty wiring connection.

- Repair the circuit and replace any open fuses.

- Go to Final procedures

If the specified value was obtained:

Checking wiring

- Remove the Motronic Engine Control Module (ECM) (J623). Refer to appropriate service manual. Using a Multimeter, check the Secondary Air Injection (AIR) Solenoid Valve 2 (N320) electrical harness connector terminal 2 to the Motronic Engine Control Module (ECM) (J623) electrical harness connector T94 terminal 28 for an open circuit.











Specified value: 1.5 ohms Max.

If the specified value was obtained:

- Check the wiring for an open circuit.

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

- If necessary, repair the faulty wiring connection.

- Go to Final procedures

If the specified value was obtained:

- Replace the Motronic Engine Control Module (ECM) (J623). Refer to appropriate service manual.

Final procedures

- Reinstall the engine covers, if necessary. Refer to the appropriate service manual.

- 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 Modes 01 - 09.

2. If necessary, erase the DTC memory. Refer to => [ Diagnostic Mode 04 - Erase DTC Memory ] Diagnostic Modes 01 - 09.

3. If the DTC memory was erased, generate readiness code. Refer to => [ Readiness Code ] Programming and Relearning.