Secondary Air Injection Solenoid Valve, Checking

Secondary Air Injection Solenoid Valve, Checking

Special tools, testers and auxiliary items required

• Multimeter.

• Wiring diagram.

Test requirements

• The Secondary Air Injection (SAI) Solenoid Valve (-N112-) fuse OK.

• The Engine Control Module (ECM) Power Supply Relay (J271) and the Fuel Pump Relay (J17) 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

• Voltage is supplied to the Secondary Air Injection (SAI) Solenoid Valve (-N112-) from the Engine Control Module (ECM) Power Supply Relay (J271) on early models, or the Fuel Pump Relay (J17) on later models. Refer to Wiring Diagrams for circuit/pin locations.

Procedure

- Disconnect the Secondary Air Injection (SAI) Solenoid Valve (-N112-) electrical harness connector.

Checking internal resistance

- Using a multimeter, check the Secondary Air Injection (SAI) Solenoid Valve (-N112-) terminals 1 to 2 for resistance.

Specified value: 3.5 - 8.5 ohms (at approx. 20 °C)

If the specified value was Not obtained:

- Replace the Secondary Air Injection (SAI) Solenoid Valve (-N112-).

If the specified value was obtained:

Checking voltage supply

Start the engine.

- Using a multimeter, check the Secondary Air Injection (SAI) Solenoid Valve (-N112-) electrical connector terminal 1 to Ground 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 (SAI) Solenoid Valve (-N112-) electrical connector terminal 1 to the Secondary Air Injection (SAI) Pump Relay (J299) or Fuel Pump Relay (J17) for a short circuit to Ground, or an open circuit. Refer to Wiring Diagrams for circuit layout/pin locations.

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

- If necessary, repair the wiring connection.

If the specified value was obtained:

Checking wiring

- Remove the Engine Control Module (ECM) (J623). Refer to the Repair Information.

- Using a multimeter, check the Secondary Air Injection (SAI) Solenoid Valve (-N112-) electrical harness connector terminal 2 to the Engine Control Module (ECM) (J623) electrical harness connector T60 for an open circuit.






Specified value: 1.5 ohms Max.

If the specified value was 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 Engine Control Module (ECM) (J623). Refer to the Repair Information.

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 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 ] Monitors, Trips, Drive Cycles and Readiness Codes.