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Fuel Injector: Service and Repair




Fuel Injection System Components, Removing and Installation







NOTE: Prior to removing the fuel injectors, the intake manifold must first be removed.


1 - Secondary Air Injection (AIR) Solenoid Valve -N112-*/**.
- Valve will be activated by Motronic Engine Control Module (ECM) - J220 - (pulsed).
- Secondary air system:

2 - Intake Manifold Change-Over Valve -N156-*/**.
- Valve will be activated by Motronic Engine Control Module (ECM) - J220 - (pulsed).
- Checking Intake Manifold Change-Over Valve - N156 -.

3 - Vacuum actuator.
- For Intake Manifold Change-Over Valve - N156 -.

4 - Vacuum reservoir.
- For Intake Manifold Change-Over Valve - N156 -.

5 - Intake manifold.
- For information regarding Removal and Installation, refer to: Vehicle /Engine, Cooling, and Exhaust /Engine /Cylinder Head Assembly / Valve Cover /Service and Repair.
Service and Repair

6 - Throttle Valve Control Module - J338 -.*
- Heated by coolant.

7 - Vacuum line.
- Press together at front to release.

8 - Motronic Engine Control Module (ECM) -J220-*.
(Motronic control module - J220 -.
- Component location: In plenum chamber.
- Checking voltage supply.
- Procedure after interrupting voltage supply.
- When replacing, erase learned values and adapt Motronic Engine Control Module (ECM) - J220 - to Throttle Valve Control Module - J338 -.

9 - Supporting frame.

10 - Connector.
- For Motronic Engine Control Module (ECM) - J220 -.
- Disconnect or connect only with ignition switched off.
- Release to disconnect.

11 - Retaining clip.
- Check seated securely.

12 - Thermostat housing.

13 - O-ring.
- Replace if damaged.

14 - Engine Coolant Temperature (ECT) sensor -G62-*.
- For Motronic Engine Control Module (ECM) - J220 -.
- With Engine Coolant Temperature (ECT) sensor - G2 -.
- Gold plated terminals.
- Release pressure in cooling system if necessary before removing components.

15 - 10 Nm.

16 - Engine Speed (RPM) Sensor -G28-*.

17 - Connector.
- Black, 4-pin.
- Terminals 3 and 4 are gold plated.
- For Oxygen Sensor (O2S) Behind Three Way Catalytic Converter (TWC) - G130 - and Oxygen Sensor (O2S) Heater 1 - Z29 -.
- Component location: Right on underside of vehicle.

18 - Oxygen Sensor (O2S) Behind Three Way Catalytic Converter (TWC) -G130-*, 50 Nm.
- Component location: In rear of Three Way Catalytic Converter.
- Remove and install with ring wrench 3337.
- Grease the threads only with G 052 112 A3 ; G 052 112 A3 must not get into the slots on the sensor body.
- If seal is leaking, replace seal.
- Oxygen Sensor (O2S) heating voltage supply via fuel pump relay.
- Check Oxygen Sensor (O2S) heating for Oxygen Sensor (O2S) Behind Three Way Catalytic Converter (TWC) - G130 -.
- Check Oxygen Sensor (O2S) and Oxygen Sensor control after Three Way Catalytic Converter (TWC).
- Check aging of Oxygen Sensor (O2S) Behind Three Way Catalytic Converter (TWC) - G130 -.
- When replacing, erase learned values and adapt Motronic Engine Control Module (ECM) - J220 - to Throttle Valve Control Module - J338 -.

19 - Connector.
- Gold plated terminals.
- Black, 6-pin.
- For Heated Oxygen Sensor (HO2S) - G39 - and Oxygen Sensor (O2S) Heater - Z19 -.
- Component location: Right on underside of vehicle.

20 - Oxygen Sensor (O2S) 1 bank 1 before catalyst -G39-*, 50 Nm.
- Component location: In front exhaust pipe.
- Remove and install with Oxygen Sensor (O2S) ring wrench 3337.
- Grease the threads only with G 052 112 A3"; "G 052 112 A3 must not get into the slots on the sensor body.
- If seal is leaking, remove and replace seal.
- Check Oxygen Sensor (O2S) heating for Heated Oxygen Sensor (HO2S). Refer to "Computers and Control Systems/Oxygen Sensor".
- Check Oxygen Sensor (O2S) and Oxygen Sensor control before Three Way Catalytic Converter (TWC).
- Check aging of Heated Oxygen Sensor (HO2S). Refer to "Computers and Control Systems/Oxygen Sensor".
- When replacing, erase learned values and adapt Motronic Engine Control Module (ECM) - J220 - to Throttle Valve Control Module - J338 -.

21 - Junction piece.

22 - Non-return valve.
- Observe installation position.
- White connector faces towards Secondary Air Injection (AIR) Solenoid Valve - N112 - / Intake Manifold Change-Over Valve - N156 -.

23 - Vacuum line.
- From vacuum reservoir: item 4.

24 - From combi-valve.
- Secondary air system:

25 - Connector.
- Black, 2-pin.
- Mark connector and component before pulling connector off.

26 - Wiring harness.
- With connectors for fuel injectors.

27 - Fuel rail.