Secondary Air Injection Solenoid Valves, Checking

Diagnostic Procedures




Secondary Air Injection Solenoid Valves, Checking

Solenoid valves are closed when no voltage is present.

Test Conditions

• Motronic Engine Control Module (ECM) Power Supply Relay (J271) -position 4- must be OK, check:

• The Ground (GND) connections between engine and body must be OK.

• Ignition switched off.

• Fuses in right instrument panel fuse holder must be OK:

Right instrument panel fuse holder





Test Sequence

Special tools, testers and auxiliary items required

• Hand multimeter (V.A.G 1526) or Multimeter (V.A.G 1715)

• Test adapter kit (V.A.G 1594)

• Wiring diagram

- Disconnect corresponding 2-pin connector from Secondary Air Injection (AIR) solenoid valve to be tested:

• 2-pin connector from Secondary Air Injection (AIR) Solenoid Valve 2 (N320) on cylinder bank 2.

• Cylinder bank 2 with cylinders 7 through 12 is located at left in direction of travel.

• All mechanical procedures and exploded view illustrations with torque specifications,

Check resistance

- Check resistance between terminals of solenoid valve. Specification: 28.0 to 32.0 ohms





If specification is not obtained:

- Replace corresponding Secondary Air Injection (AIR) Solenoid Valve:

• Secondary Air Injection (AIR) Solenoid Valve (N112),

• Secondary Air Injection (AIR) Solenoid Valve 2 (N320),

- Erase DTC memory of Engine Control Module => [ Diagnostic Mode 04 - Erase DTC Memory ] Diagnostic Modes 01 - 09, Diagnostic mode 4: Reset/erase diagnostic data.

- Generate readiness code => [ Readiness Code, Generating ] Monitors, Trips, Drive Cycles and Readiness Codes.

If specification is obtained:

- Check wires to control module according to wiring diagram.

Check wires to control module

Cylinder bank 1

- Connect test box to Engine Control Module (ECM) (J623) wiring harness on connecting test box for wiring test, refer to Repair Manual,

Cylinder bank 2

- Connect test box to E ngine Control Module (ECM) 2 (J624) wiring harness on connecting test box for wiring test, refer to Repair Manual,

Cylinder bank 1 and 2

- Check wire between test box socket 44 + terminal 2 of 2-pin connector for open circuit according to wiring diagram. Wiring resistance: max. 1.5 ohms





- Check the wire for short circuit to B+ and Ground (GND). Specification: infinite ohms

- Check wire between 1-pin connector terminal 2 and Motronic Engine Control Module (ECM) Power Supply Relay (J271) for open circuit according to wiring diagram. Wiring resistance: max. 1.5 ohms

- Erase DTC memory of Engine Control Module (ECM) => [ Diagnostic Mode 04 - Erase DTC Memory ] Diagnostic Modes 01 - 09, Diagnostic mode 4: Reset/erase diagnostic data.

- Generate readiness code => [ Readiness Code, Generating ] Monitors, Trips, Drive Cycles and Readiness Codes.

If no malfunctions are detected in the wires and the resistance value is OK:

Cylinder bank 1

- Replace Engine Control Module (ECM) (J623),

Cylinder bank 2

- Replace Engine Control Module (ECM) 2 (J624),