Computers and Control Systems: Service and Repair
Fuel Injection System, Servicing
NOTES:
- Fuel hoses in engine compartment must be secured with spring type clips. The use of clamp or screw type clips is not permissible.
- The control module for the fuel injection and ignition system is equipped with a Diagnostic Trouble Code (DTC) memory. Before carrying out repairs, adjustment work and troubleshooting the DTC memory must be checked and the vacuum connections checked (outside air).
- Components marked with an asterisk (*) are checked via the On Board Diagnostic (OBD) program See "Checking DTC Memory (Function 02)".
- Components marked with two asterisks (**) are checked via the output Diagnostic Test Mode (DTM) See "Output Diagnostic Test Mode (Function 03)".
- For trouble-free operation of the electrical components, a voltage of at least 11.5 volts is necessary.
- Do not use sealants containing silicone. Traces of silicone drawn into the engine are not consumed and will damage the oxygen sensor
- Do not spray anything in the area of the oxygen sensor. connectors. To function correctly oxygen sensors require reference air, which they receive via the connector. If contact spray gets into the oxygen sensor via this path it will lead to damage/malfunctions.
- During some checks it can happen that the ECM will recognize and store a malfunction. Therefore after completing all checks and repairs the DTC memory must be checked and if necessary erased.
- Safety precautions See "Multiport Fuel Injection System Safety Precautions". Technician Safety Information
- Rules for cleanliness See "Multiport Fuel Injection System Rules For Cleanliness". [1][2]Technician Safety Information
- Technical data See "Multiport Fuel Injection System, Technical Data". Specifications
1 - Air Cleaner (ACL)
- Disassembling and assembling
2 - Connector
- 4-pin
- Mass Air Flow (MAF) sensor -G70-
3 - Evaporative Emission (EVAP) canister purge regulator valve N80.*/**
- EVAP system
4 - Intake air duct
5 - Positive Crankcase Ventilation (PCV) valve
6 - Connector
- 8-pin
- For throttle valve control module -J338-
7 - Intake manifold, upper
- First tighten to lower intake manifold and then to both rear supports -21-
- Disassembling and assembling See "Upper Intake Manifold, Disassembling and Assembling".
8 - Throttle valve control module -J338-*
- If replaced initiate basic setting See "On-Board Diagnostics II With VAG 1551/Basic Setting, Initiating (Function 04)". Testing and Inspection
9 - Connector
- 68-pin
- Only disconnect or connect with ignition switched off
10 - Mounting plate
- For Engine Control Module (ECM) -J220-
11 - 10 Nm (7 ft lb)
12 - Engine Control Module (ECM) -J220-*
- Location: in plenum chamber, right side
- For fuel injection system, Oxygen Sensor (O2S) control, Evaporative Emission (EVAP) canister purge regulator valve, speed governing via fuel pump relay, idle speed control, ignition and On Board Diagnostic (OBD)
- Check ECM coding See "Coding Control Module (Function 07)".
- If replaced initiate basic setting See "On-Board Diagnostics II With VAG 1551/Basic Setting, Initiating (Function 04)". Testing and Inspection
13 - To brake booster
14 - To A/C
15 - Retaining clip
- Check seated securely
16 - O-ring
- Replace if damaged
17 - Engine Coolant Temperature (ECT) sensor -G62-*
- Black, Engine Coolant Temperature (ECT) sensor -G2-
- Input to fuel injection system
- Checking See "Engine Coolant Temperature Sensor, Checking".
- If necessary before removing, release pressure from cooling system
18 - Connector
- 4-pin
- Terminals 1 and 3 for -G62-
19 - Connector
20 - 20 Nm (15 ft lb)
21 - Support
- Between intake manifold upper section and cylinder head
22 - Gasket
- Always replace
23 - Intake manifold, lower
- Disassembling and assembling See "Lower Intake Manifold, Disassembling and Assembling".
24 - Engine speed (RPM) sensor -G28-*
25 - Spacer ring
26 - Heated Oxygen Sensor (HO2S) 2 -G108- *
- 50 Nm (37 ft lb)
- Installation position. Three Way Catalytic Converter (TWC)
- Only grease threads with "G5"; G5 must not get into the slots on the HO2S body
- Checking HO2S 2 and O2S control See "Heated Oxygen Sensor and Oxygen Sensor Control, Checking". Testing and Inspection
- O2S heating voltage supply via fuel pump relay -J17-
- Checking O2S heating See "Oxygen Sensor Heating, Checking". Testing and Inspection
27 - Connector
- Brown, 4-pin
- For HO2S 2 -G108- and O2S heating (after three way catalytic converter)
- Secured to rear engine mount
28 - Heated Oxygen Sensor (HO2S) -G39-*
- 50 Nm (37 ft lb)
- Installation position: before Three Way Catalytic Converter (TWC)
- Only grease threads with "G5"; G5 must not get into the slots on the HO2S body
- Checking HO2S and oxygen sensor control See "Heated Oxygen Sensor and Oxygen Sensor Control, Checking". Testing and Inspection
- O2S heating voltage supply via fuel pump relay -J17-
- Checking O2S heating See "Oxygen Sensor Heating, Checking". Testing and Inspection
29 - Connector
- Black, 4-pin
- For HO2S and oxygen sensor heating (before three way catalytic converter)
- Secured to rear engine mount
30 - Deflector
31 - To crankcase
32 - Hose
- To warm air deflector plate on exhaust manifold
33 - Retaining ring
34 - Supply line
- White arrow
- Secure with spring-type clips
- From fuel delivery unit in fuel tank
35 - Return line
- Blue arrow
- Secure with spring-type clips
- To fuel tank