Multiport Fuel Injection (mfi), Generic Scan Tool (1.8l 5v Turbo, Amb) Audi A4 B7

Safety precautions

To reduce the risk of personal injury and/or damage to the fuel injection and ignition system, always observe the following

1. Only disconnect and reconnect wires for injection and ignition system, including test leads, when ignition is turned off.
2. If engine is to be cranked at starting RPM without starting (e.g. for compression testing), disconnect connector from ignition coils and from fuel injectors.
3. It is possible that the control module will recognize a malfunction and store a DTC during some tests. After completing all tests and repairs, DTC memory should therefore be checked and erased if necessary. Readiness code must be generated after DTC memory is erased. See «READINESS CODE, GENERATING»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb) .
4. Always switch ignition off before cleaning engine.

If test and measuring equipment is required during road test, note the following

Rules of cleanliness

When working on the fuel supply or fuel injection systems, the following "6 rules of cleanliness" should be carefully observed

1. Thoroughly clean all connections and the surrounding area before disconnecting.
2. Place parts that have been removed on a clean surface and cover them. Use lint-free cloths only!
3. Carefully cover over opened components or seal, if repairs are not performed immediately.
4. Only install clean components: Only unpack replacement parts immediately prior to installation. Do not use parts that have been stored loose (in tool boxes etc.)
5. When the system is open: Avoid working with compressed air. Do not move vehicle unless absolutely necessary.
6. Disconnected electrical harness connectors: Protect from dirt and moisture. Be sure harness connector is dry before connecting.

Technical data

TECHNICAL DATA

Overview of component locations

Note. The following list refers to (Scheme 123).

1. Evaporative Emission (EVAP) Canister Purge Regulator Valve -N80- Checking. See «CHECKING EVAPORATIVE EMISSION (EVAP) CANISTER PURGE REGULATOR VALVE -N80»(/audi/a4/b7-2004-2009/remont/fuel-system/#fuel-supply-generic-scan-tool-18l-5v-turbo-amb) .
2. Heated Oxygen Sensor (HO2S) -G39- before catalytic converter, 55 N.m Constant oxygen sensor Check Oxygen Sensor (O2S) and oxygen sensor control before Three Way Catalytic Converter (TWC). See «Heated Oxygen Sensor (HO2S) -G39- and oxygen sensor regulation before catalytic converter, checking»(/audi/a4/b7-2004-2009/remont/fuel-system/#multiport-fuel-injection-mfi-generic-scan-tool-18l-5v-turbo-amb) . Check oxygen sensor heater for Oxygen Sensor (O2S) before Three Way Catalytic Converter (TWC). See «Oxygen Sensor (O2S) Heater -Z19- before catalytic converter, checking»(/audi/a4/b7-2004-2009/remont/fuel-system/#multiport-fuel-injection-mfi-generic-scan-tool-18l-5v-turbo-amb) . Removing and installing. See «OXYGEN SENSORS, REMOVING AND INSTALLING»(ref-213311-S02249091782005122900000) .
3. Oxygen Sensor (O2S) Behind Three Way Catalytic Converter (TWC) -G130-, 55 N.m Check Oxygen Sensor (O2S) and oxygen sensor control behind Three Way Catalytic Converter (TWC). See «OXYGEN SENSORS AND OXYGEN SENSOR REGULATION BEHIND CATALYTIC CONVERTER, CHECKING»(/audi/a4/b7-2004-2009/remont/fuel-system/#multiport-fuel-injection-mfi-generic-scan-tool-18l-5v-turbo-amb__oxygen-sensors-and-oxygen-sensor-regulation) . Check oxygen sensor heater for Oxygen Sensor (O2S) behind Three Way Catalytic Converter (TWC). See «OXYGEN SENSOR (O2S) HEATER 1 -Z29- BEHIND CATALYTIC CONVERTER, CHECKING»(/audi/a4/b7-2004-2009/remont/fuel-system/#multiport-fuel-injection-mfi-generic-scan-tool-18l-5v-turbo-amb) . Removing and installing. See «OXYGEN SENSORS, REMOVING AND INSTALLING»(ref-213311-S02249091782005122900000) .
4. Combination valve for Secondary Air Injection (AIR) system Checking. See «COMBINATION VALVE FOR SECONDARY AIR INJECTION (AIR) SYSTEM, CHECKING FUNCTION AND FOR PROPER SEAL»(ref-213311-S27009014962005122900000) .
5. Engine Coolant Temperature (ECT) sensor -G62- Checking. See «ENGINE COOLANT TEMPERATURE (ECT) SENSOR -G62-, CHECKING»(/audi/a4/b7-2004-2009/remont/fuel-system/#multiport-fuel-injection-mfi-generic-scan-tool-18l-5v-turbo-amb) . If necessary, release pressure of cooling system before removing
6. Engine Speed (RPM) Sensor -G28- Checking. See «ENGINE SPEED (RPM) SENSOR -G28-, CHECKING»(/audi/a4/b7-2004-2009/remont/fuel-system/#multiport-fuel-injection-mfi-generic-scan-tool-18l-5v-turbo-amb__engine-speed-rpm-sensor-g28-checking) .
7. Secondary Air Injection (AIR) solenoid valve -N112- Component location. See «Component location of Secondary Air Injection (AIR) Solenoid Valve -N112- and Recirculating valve for turbocharger -N249»(/audi/a4/b7-2004-2009/remont/fuel-system/#multiport-fuel-injection-mfi-generic-scan-tool-18l-5v-turbo-amb__component-location-of-secondary-air-injection) .
8. Bracket for harness connectors Component location. See «Component location of harness connectors»(/audi/a4/b7-2004-2009/remont/fuel-system/#multiport-fuel-injection-mfi-generic-scan-tool-18l-5v-turbo-amb__component-location-of-harness-connectors) . Accessible with coolant expansion tank unbolted and swung to the side.
9. Instrument cluster with Malfunction Indicator Lamp (MIL) -K83-. See «MALFUNCTION INDICATOR LAMP (MIL) -K83- IN INSTRUMENT CLUSTER»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb__malfunction-indicator-lamp-mil-k83-in) . With Electronic Power Control (EPC) Warning Lamp -K132- ("EPC" warning lamp). See «ELECTRONIC POWER CONTROL (EPC) WARNING LAMP -K132- IN INSTRUMENT CLUSTER»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb__electronic-power-control-epc-warning-lamp) .
10. Throttle Position (TP) sensor -G79- and sender 2 for accelerator pedal position -G185- Component location. See «COMPONENT LOCATION, THROTTLE POSITION (TP) SENSOR -G79- AND SENDER 2 FOR ACCELERATOR PEDAL POSITION -G185»(/audi/a4/b7-2004-2009/remont/fuel-system/#multiport-fuel-injection-mfi-generic-scan-tool-18l-5v-turbo-amb__component-location-throttle-position-tp-sensor) . Checking. See «THROTTLE POSITION (TP) SENSOR, CHECKING»(/audi/a4/b7-2004-2009/remont/fuel-system/#fuel-supply-generic-scan-tool-18l-5v-turbo-amb) . When replacing, adapt kickdown function, to do so switch on ignition and press accelerator pedal all the way down past the kickdown point and hold in position for at least 20 seconds Removing and installing accelerator pedal module. See «ACCELERATOR LINKAGE, SERVICING»(/audi/a4/b7-2004-2009/remont/fuel-system/#fuel-supply-generic-scan-tool-18l-5v-turbo-amb__accelerator-linkage-servicing) .
11. Brake light switch -F- and brake pedal switch -F47- Component location. See «COMPONENT LOCATION OF BRAKE LIGHT SWITCH -F- AND BRAKE PEDAL SWITCH -F47-, CLUTCH VACUUM VENT VALVE SWITCH -F36»(/audi/a4/b7-2004-2009/remont/fuel-system/#multiport-fuel-injection-mfi-generic-scan-tool-18l-5v-turbo-amb__component-location-of-brake-light-switch) .
12. Clutch vacuum vent valve switch -F36- Component location. See «COMPONENT LOCATION OF BRAKE LIGHT SWITCH -F- AND BRAKE PEDAL SWITCH -F47-, CLUTCH VACUUM VENT VALVE SWITCH -F36»(/audi/a4/b7-2004-2009/remont/fuel-system/#multiport-fuel-injection-mfi-generic-scan-tool-18l-5v-turbo-amb__component-location-of-brake-light-switch) . Checking. See «CLUTCH VACUUM VENT VALVE SWITCH -F36-, CHECKING»(/audi/a4/b7-2004-2009/remont/fuel-system/#multiport-fuel-injection-mfi-generic-scan-tool-18l-5v-turbo-amb__clutch-vacuum-vent-valve-switch-f36) .
13. E-box, plenum chamber Component locations. See «COMPONENT LOCATION OF ENGINE CONTROL MODULE (ECM) IN E-BOX, PLENUM CHAMBER»(/audi/a4/b7-2004-2009/remont/fuel-system/#multiport-fuel-injection-mfi-generic-scan-tool-18l-5v-turbo-amb) and «COMPONENT LOCATIONS IN E-BOX, PLENUM CHAMBER»(/audi/a4/b7-2004-2009/remont/fuel-system/#multiport-fuel-injection-mfi-generic-scan-tool-18l-5v-turbo-amb__component-locations-in-e-box-plenum-chamber) . Component location for Motronic Engine Control Module (ECM) -J220- with integrated Barometric Pressure (BARO) Sensor -F96- Check voltage supply of Engine Control Module (ECM). See «VOLTAGE SUPPLY FOR ENGINE CONTROL MODULE (ECM), CHECKING»(/audi/a4/b7-2004-2009/remont/fuel-system/#multiport-fuel-injection-mfi-generic-scan-tool-18l-5v-turbo-amb) . Replacing Engine Control Module (ECM). See «ENGINE CONTROL MODULE (ECM), REMOVING AND INSTALLING»(/audi/a4/b7-2004-2009/remont/fuel-system/#multiport-fuel-injection-mfi-generic-scan-tool-18l-5v-turbo-amb) . Component location of Motronic Engine Control Module (ECM) voltage supply relay -J271- Check Motronic Engine Control Module (ECM) voltage supply relay -J271-. See «CHECK MOTRONIC ENGINE CONTROL MODULE (ECM) POWER SUPPLY RELAY -J271- AND ACTIVATION»(/audi/a4/b7-2004-2009/remont/fuel-system/#multiport-fuel-injection-mfi-generic-scan-tool-18l-5v-turbo-amb__check-motronic-engine-control-module-ecm) Component location for Engine Electronics Fuse -S282- for Motronic Component location of Secondary Air Injection (AIR) pump relay -J299- Checking Secondary Air Injection (AIR) Pump Relay -J299-. See «SECONDARY AIR INJECTION (AIR) PUMP RELAY -J299- AND ACTIVATION, CHECKING»(ref-213311-S33854299092005122900000) .
14. Fuel Pump (FP) Relay -J17- Component location. See «COMPONENT LOCATION OF FUEL PUMP (FP) RELAY -J17»(/audi/a4/b7-2004-2009/remont/fuel-system/#multiport-fuel-injection-mfi-generic-scan-tool-18l-5v-turbo-amb__component-location-of-fuel-pump-fp) . Checking. See «FUEL PUMP (FP) RELAY -J17- AND ACTIVATION, CHECKING»(/audi/a4/b7-2004-2009/remont/fuel-system/#multiport-fuel-injection-mfi-generic-scan-tool-18l-5v-turbo-amb__fuel-pump-fp-relay-j17-and) .
15. Charge Air Pressure Sensor -G31- Component location. See «COMPONENT LOCATION OF CHARGE AIR PRESSURE SENSOR -G31»(/audi/a4/b7-2004-2009/remont/fuel-system/#multiport-fuel-injection-mfi-generic-scan-tool-18l-5v-turbo-amb__component-location-of-charge-air-pressure) . Checking. See «CHARGE AIR PRESSURE SENSOR -G31-, CHECKING»(/audi/a4/b7-2004-2009/remont/fuel-system/#multiport-fuel-injection-mfi-generic-scan-tool-18l-5v-turbo-amb) .
16. Throttle Valve Control Module -J338- With throttle drive (power accelerator actuation) -G186-, angle sensor -1- for throttle drive (power accelerator actuation) -G187-, and angle sensor -2- for throttle drive (power accelerator actuation) -G188- Checking. See «THROTTLE VALVE CONTROL MODULE -J338-, CHECKING»(/audi/a4/b7-2004-2009/remont/fuel-system/#multiport-fuel-injection-mfi-generic-scan-tool-18l-5v-turbo-amb__throttle-valve-control-module-j338-checking) . When replacing, perform adaptation, for this purpose switch on ignition for at least 20 seconds without starting engine or depressing accelerator pedal
17. Intake Air Temperature (IAT) Sensor -G42- Checking. See «INTAKE AIR TEMPERATURE (IAT) SENSOR -G42-, CHECKING»(/audi/a4/b7-2004-2009/remont/fuel-system/#multiport-fuel-injection-mfi-generic-scan-tool-18l-5v-turbo-amb__intake-air-temperature-iat-sensor-g42) .
18. Recirculating valve for turbocharger -N249- Component location. See «COMPONENT LOCATION OF SECONDARY AIR INJECTION (AIR) SOLENOID VALVE -N112- AND RECIRCULATING VALVE FOR TURBOCHARGER -N249»(/audi/a4/b7-2004-2009/remont/fuel-system/#multiport-fuel-injection-mfi-generic-scan-tool-18l-5v-turbo-amb__component-location-of-secondary-air-injection) .
19. Knock Sensor (KS) 1 -G61
20. Knock Sensor (KS) 2 -G66
21. Camshaft Position (CMP) Sensor -G40- Checking. See «CAMSHAFT POSITION (CMP) SENSOR -G40-, CHECKING»(/audi/a4/b7-2004-2009/remont/ignition-system/#ignitionglow-plug-system-generic-scan-tool-18l-5v-turbo-amb__camshaft-position-cmp-sensor-g40-checking) .
22. Fuel injectors Cylinder 1 Fuel Injector -N30- Cylinder 2 fuel injector -N31- Cylinder 3 fuel injector -N32- Cylinder 4 fuel injector -N33- Checking. See «FUEL INJECTORS, CHECKING»(/audi/a4/b7-2004-2009/remont/fuel-system/#multiport-fuel-injection-mfi-generic-scan-tool-18l-5v-turbo-amb) . Removing and installing. See «FUEL INJECTORS, REMOVING AND INSTALLING»(/audi/a4/b7-2004-2009/remont/fuel-system/#multiport-fuel-injection-mfi-generic-scan-tool-18l-5v-turbo-amb__fuel-injectors-removing-and-installing) .
23. Ignition coils with power output stage Ignition Coil 1 with Power Output Stage -N70- Ignition Coil 2 with Power Output Stage -N127- Ignition Coil 3 with Power Output Stage -N291- Ignition Coil 4 with Power Output Stage -N292- Checking. See «IGNITION COILS WITH POWER OUTPUT STAGES, CHECKING»(/audi/a4/b7-2004-2009/remont/ignition-system/#ignitionglow-plug-system-generic-scan-tool-18l-5v-turbo-amb) .
24. Wastegate Bypass Regulator Valve -N75- Checking. See «WASTEGATE BYPASS REGULATOR VALVE -N75-, CHECKING»(/audi/a4/b7-2004-2009/remont/fuel-system/#multiport-fuel-injection-mfi-generic-scan-tool-18l-5v-turbo-amb) .
25. Mass Air Flow (MAF) Sensor -G70- Checking. See «MASS AIR FLOW (MAF) SENSOR -G70-, CHECKING»(/audi/a4/b7-2004-2009/remont/fuel-system/#multiport-fuel-injection-mfi-generic-scan-tool-18l-5v-turbo-amb) .
26. Secondary Air Injection (AIR) Pump Motor -V101- Checking. See «CHECK VOLTAGE SUPPLY OF THE SECONDARY AIR INJECTION (AIR) PUMP MOTOR»(ref-213311-S00802580322005122900000) .

Component location, Throttle Position (TP) sensor -G79- and sender 2 for accelerator pedal position -G185

1. integrated in accelerator pedal module (arrow) NOTE: Throttle Position (TP) Sensor -G79- and Sender -2- for accelerator pedal position -G185- are integrated in the accelerator pedal module and cannot be replaced separately.

Component location of brake light switch -F- and brake pedal switch -F47-, clutch vacuum vent valve switch -F36

1. Clutch vacuum vent valve switch -F36
2. Brake light switch -F-, brake pedal switch -F47

Scheme 123

Removing and installing switch

See BRAKELIGHT SWITCH .

Scheme 124

Component locations in E-box, plenum chamber

1. 1.1 - Not assigned
2. 1.2 - Not assigned
3. 2 - Secondary Air Injection (AIR) Pump Relay -J299
4. 3 - Motronic Engine Control Module (ECM) voltage supply relay -J271
5. 4 - Not assigned

1. Engine Electronics Fuse S282
2. Fuse S130 for Secondary Air Injection (AIR) pump
3. Not assigned

Scheme 125

Component location of harness connectors

The following harness connectors are located below the coolant expansion tank

1. 3-pin harness connector, green for Knock Sensor (KS) 1 -G61
2. 4-pin harness connector, brown for Oxygen Sensor (O2S) behind Three Way Catalytic Converter (TWC) -G130- and Oxygen Sensor (O2S) Heater 1 -Z29- (bank 1 sensor 2)
3. 3-pin harness connector, gray for Engine Speed (RPM) sensor -G28
4. 3-pin harness connector, blue for Knock Sensor (KS) 2 -G66
5. 6-pin harness connector, black for Heated Oxygen Sensor (HO2S) -G39- before catalytic converter and Oxygen Sensor (O2S) Heater -Z19- (bank 1 sensor 1)

Note. Coolant reservoir screw (arrow) must be removed and coolant reservoir must be placed to the side in order to access harness connectors. The coolant hoses remain connected.

Scheme 126

Component location of Fuel Pump (FP) Relay -J17

1. on 9-pin relay carrier in driver's footwell, left side, position 1

Component location of Secondary Air Injection (AIR) Solenoid Valve -N112- and Recirculating valve for turbocharger -N249

1. Component location: Below intake manifold

1. Recirculating valve for turbocharger -N249
2. Secondary Air Injection (AIR) solenoid valve -N112

Note. Illustration depicts intake manifold removed, from below.

Scheme 127

Component location of Charge Air Pressure Sensor -G31

Charge Air Pressure Sensor -G31- (arrow) bolted into charge air cooler at top

Scheme 128

Fuel rail with fuel injectors - component overview

Note. To prevent damage to catalytic converter the fuel system must be bled after repair work on fuel distributor or on fuel lines. See FUEL SYSTEM, BLEEDING . The vehicle must only be started after bleeding.

Note. The following list refers to (Scheme 133).

1. Socket-head bolt -10 N.m
2. Protective cap
3. Retaining clip Make sure clip is correctly seated on fuel injector and fuel rail
4. Intake manifold with Throttle Valve Control Module -J338- with Intake Air Temperature (IAT) Sensor -G42
5. Fuel injector insert - 3 N.m use fluid securing material D 000 600 A2 to insert.
6. O-ring Removing and installing. See «FUEL INJECTORS, REMOVING AND INSTALLING»(/audi/a4/b7-2004-2009/remont/fuel-system/#multiport-fuel-injection-mfi-generic-scan-tool-18l-5v-turbo-amb__fuel-injectors-removing-and-installing) . replace Coat with clean engine oil
7. Fuel injectors Cylinder 1 Fuel Injector -N30- Cylinder 2 fuel injector -N31- Cylinder 3 fuel injector -N32- Cylinder 4 fuel injector -N33- Removing and installing. See «FUEL INJECTORS, REMOVING AND INSTALLING»(/audi/a4/b7-2004-2009/remont/fuel-system/#multiport-fuel-injection-mfi-generic-scan-tool-18l-5v-turbo-amb__fuel-injectors-removing-and-installing) .
8. O-ring Removing and installing. See «FUEL INJECTORS, REMOVING AND INSTALLING»(/audi/a4/b7-2004-2009/remont/fuel-system/#multiport-fuel-injection-mfi-generic-scan-tool-18l-5v-turbo-amb__fuel-injectors-removing-and-installing) . Replace: Coat with clean engine oil
9. Fuel supply line Tighten to 25 N.m
10. Harness connector for injectors 4x

Fuel injectors, removing and installing

1. Remove engine cover (arrows).
2. Disconnect electrical harness connectors at Camshaft Position (CMP) sensor -1- and at fuel injectors -2-.
3. Remove retaining bolts -3- of fuel distributor.
4. Remove fuel distributor together with fuel injectors from intake manifold simultaneously upward and place it on a clean rag in engine compartment. CAUTION: Fuel system is under pressure! Before opening system, place rags around the connection area. Then release pressure by carefully loosening connection.
5. Disengage retaining clip and remove fuel injector. NOTE: Fuel line must be removed before replacing fuel distributor.

Installing

Installation is reverse of removal, noting the following

1. Replace O-rings at all opened connection points. (Never remove plastic cap from valve head to replace front O-ring - lift O-ring off over plastic cap).
2. Lubricate O-rings with clean engine oil.
3. Make sure fuel injectors are in place and seated correctly
4. Check clips for proper seating.
5. Place fuel rail with secured fuel injectors onto intake manifold, and apply uniform pressure to press it in.

Tightening torque

TIGHTENING TORQUE: FUEL DISTRIBUTOR

Recommended special tools and equipment

1. V.A.G 1318 Fuel INJ. Pressure Gauge -CIS K-Jetronic with V.A.G 1318/21 adapter
2. VAG1598/31 test box
3. VAS 5226 catch reservoir

Scheme 129

Scheme 130

1. Close shut-off valve on special tool V.A.G. 1318/21 by turning in "-" direction up to stop. CAUTION: Work on the fuel system must only be performed when engine is cold! Fuel system is under pressure! Before opening system, place rags around the connection area. Then release pressure by carefully loosening connection.
2. Unthread sealing cap from bleeder connection -2- and connect V.A.G 1318/21 adapter instead.
3. Connect V.A.G. 1318/21 adapter and VAS 5226 catch reservoir with assistance of V.A.G. 1318 pressure gauge. WARNING: All connection areas must be secured!
4. Open shut-off valve on special tool V.A.G. 1318/21 by turning in "+" direction.
5. Switch ignition on. Fuel pump starts up briefly
6. Switch ignition off.

If the fuel pump does not operate, or fuel flows out on catch reservoir VAS 5226 continuously with bubbles

1. Connect test box to wiring harness of Engine Control Module (ECM). See «TEST BOX, CONNECTING FOR WIRING AND COMPONENT TEST»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb) ; ECM is not connected.
2. Bridge terminals 1 and 65 at test box using wires e.g. from V.A.G 1594 A adapter test kit.
3. Switch ignition on.
4. Switch ignition off. CAUTION: Fuel system is under pressure! Before opening system, place rags around the connection point. Then release pressure by carefully loosening connection.
5. Close shut-off valve on special tool V.A.G. 1318/21 by turning in "-" direction up to stop.
6. Remove V.A.G. 1318/21 adapter from bleeder connection.
7. Thread on sealing cap to bleeder connection -2-.

1. VAG1526A hand multimeter
2. VAG1594A connector test kit
3. VAG1598/31 test box

Test requirements

1. Fuse for oxygen sensor heater OK See appropriate System Wiring Diagram article.
2. Ground (GND) connections at engine and transmission OK
3. Fuel Pump (FP) Relay OK; checking. See «FUEL PUMP (FP) RELAY -J17- AND ACTIVATION, CHECKING»(/audi/a4/b7-2004-2009/remont/fuel-system/#multiport-fuel-injection-mfi-generic-scan-tool-18l-5v-turbo-amb__fuel-pump-fp-relay-j17-and) .
4. Ignition switched off.

Note. Voltage is supplied to Oxygen Sensor (O2S) Heater -Z19- via the Fuel Pump (FP) relay. When servicing terminals in harness connector of Heated Oxygen Sensor (HO2S), use only gold-plated terminals.

Scheme 131

1. Disconnect 6-pin harness connector (black) -5- to Heated Oxygen Sensor (HO2S) -G39- before catalytic converter. NOTE: Coolant reservoir screw (arrow) must be removed and coolant reservoir must be placed to the side in order to access harness connector. The coolant hoses remain connected.
2. Connect multimeter between terminal 3 and 4 for resistance measurement. Specified value at room temperature: 2.5 ... 10 ohms
3. Replace Heated Oxygen Sensor (HO2S) -G39-.

Checking internal resistance

1. Connect multimeter between terminal 3 and 4 for resistance measurement. Specified value at room temperature: 2.5 ... 10 ohms

If specified value is not obtained

1. Replace oxygen sensor before catalytic converter. See «OXYGEN SENSORS, REMOVING AND INSTALLING»(ref-213311-S02249091782005122900000) .

If specified value is obtained

Checking voltage supply

1. Connect multimeter between terminal 3 and 4 for voltage measurement.
2. Operate starter briefly. Specified value: approx. battery voltage
3. Switch ignition off.

If there is no voltage

1. Connect multimeter for voltage measurement as follows: OXYGEN SENSOR HEATER -Z19- TERMINAL 3 VOLTAGE Harness connector Terminal Measure to 3 Engine Ground (GND)
2. Operate starter briefly. Specified value: approx. battery voltage
3. Switch ignition off.

If there is no voltage again

1. Check wire connection from harness connector terminal 3 to Fuel Pump (FP) Relay -J17- via fuse for open circuit according to wiring diagram. Specified value: Wire resistance max 1.5 ohms
2. If necessary, repair wire connection.

If voltage supply is OK

Scheme 132

1. Connect multimeter for voltage measurement as follows: OXYGEN SENSOR HEATER -Z19- TERMINAL 4 VOLTAGE Harness connector Terminal Measure to 4 B+
2. Operate starter briefly. Specified value: approx. battery voltage
3. Switch ignition off.

If specified value is not obtained

Scheme 133

1. Connect test box to wiring harness of Engine Control Module (ECM). See «TEST BOX, CONNECTING FOR WIRING AND COMPONENT TEST»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb) ; ECM is not connected.
2. Check the following wire connections for open circuit according to wiring diagram: OXYGEN SENSOR HEATER -Z19- TERMINAL 4 & TEST BOX 5 Harness connector Terminal Test box Socket 4 5 Specified value: Wire resistance max 1.5ohms
3. Also check wires for short circuit to B+ and Ground (GND). Specified value: INFINITY ohms (no continuity)
4. If necessary, repair wire connection.

If no malfunctions are detected

1. Replace Engine Control Module (ECM).

Final procedures

After repair work, the following work steps must be performed in the mentioned sequence

1. Check DTC memory. See «MODE 3: CHECK DTC MEMORY»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb__mode-3-check-dtc-memory) .
2. If necessary, erase DTC memory. See «MODE 4: RESET/ERASE DIAGNOSTIC DATA»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb__mode-4-reseterase-diagnostic-data) .
3. Generate readiness code. See «READINESS CODE, GENERATING»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb) .

1. End diagnosis and switch ignition off.

1. VAG1526A hand multimeter
2. VAG1594A connector test kit
3. VAG1598/31 test box

1. Fuse for oxygen sensor heater OK See appropriate System Wiring Diagram article.
2. Ground (GND) connections at engine and transmission OK
3. Fuel Pump (FP) Relay OK; checking. See «FUEL PUMP (FP) RELAY -J17- AND ACTIVATION, CHECKING»(/audi/a4/b7-2004-2009/remont/fuel-system/#multiport-fuel-injection-mfi-generic-scan-tool-18l-5v-turbo-amb__fuel-pump-fp-relay-j17-and) .
4. Ignition switched off.

Note. Voltage is supplied to Oxygen Sensor (O2S) Heater 1 -Z29- via the Fuel Pump (FP) relay. When servicing terminals in harness connector of Heated Oxygen Sensor (HO2S), use only gold-plated terminals.

Work procedure

1. Disconnect 4-pin harness connector -2- (brown) to Oxygen Sensor (O2S) behind Three Way Catalytic Converter (TWC) -G130-.

Note. Coolant reservoir screw (arrow) must be removed and coolant reservoir must be placed to the side in order to access harness connector. The coolant hoses remain connected.

Scheme 134

1. Connect multimeter between terminal 1 and 2 for resistance measurement. Specified value at room temperature: 6.4 ... 47.5 ohms

If specified value is not obtained

1. Replace oxygen sensor behind catalytic converter. See «OXYGEN SENSORS, REMOVING AND INSTALLING»(ref-213311-S02249091782005122900000) .

If specified value is obtained

1. Connect multimeter between terminal 1 and 2 for voltage measurement.
2. Operate starter briefly. Specified value: approx. battery voltage

If there is no voltage

1. Connect multimeter for voltage measurement as follows: OXYGEN SENSOR HEATER -Z29- TERMINAL 1 VOLTAGE Harness connector Terminal Measure to 1 Engine Ground (GND)
2. Operate starter briefly. Specified value: approx. battery voltage
3. Switch ignition off.

If there is no voltage again

1. Check wire connection from harness connector terminal 1 to Fuel Pump (FP) Relay -J17- via fuse for open circuit according to wiring diagram. Specified value: Wire resistance max 1.5 ohms
2. If necessary, repair wire connection.

If voltage supply is OK

Scheme 135

1. Connect multimeter for voltage measurement as follows: OXYGEN SENSOR HEATER -Z29- TERMINAL 2 VOLTAGE Harness connector Terminal Measure to 2 B+
2. Operate starter briefly. Specified value: approx. battery voltage, possibly fluctuating
3. Switch ignition off.

If specified value is not obtained

Scheme 136

1. Connect test box to wiring harness of Engine Control Module (ECM). See «TEST BOX, CONNECTING FOR WIRING AND COMPONENT TEST»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb) ; ECM is not connected.
2. Check the following wire connections for open circuit according to wiring diagram: OXYGEN SENSOR HEATER -Z29- TERMINAL 2 & SOCKET 63 Harness connector Terminal Test box Socket 2 63 Specified value: Wire resistance max 1.5ohms
3. Also check wires for short circuit to B+ and Ground (GND). Specified value: INFINITY ohms (no continuity)
4. If necessary, repair wire connection.

If no malfunctions are detected

1. Replace Engine Control Module (ECM).

After repair work, the following work steps must be performed in the mentioned sequence

1. Check DTC memory. See «MODE 3: CHECK DTC MEMORY»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb__mode-3-check-dtc-memory) .
2. If necessary, erase DTC memory. See «MODE 4: RESET/ERASE DIAGNOSTIC DATA»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb__mode-4-reseterase-diagnostic-data) .
3. Generate readiness code. See «READINESS CODE, GENERATING»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb) .

1. End diagnosis and switch ignition off.

1. VAG1526A hand multimeter
2. VAG1594A connector test kit
3. VAG1598/31 test box

Component location. See OVERVIEW OF COMPONENT LOCATIONS .

1. Fuse for Mass Air Flow (MAF) sensor OK See appropriate System Wiring Diagram article.
2. Ground (GND) connections at engine and transmission OK
3. Fuel Pump (FP) Relay OK; checking. See «FUEL PUMP (FP) RELAY -J17- AND ACTIVATION, CHECKING»(/audi/a4/b7-2004-2009/remont/fuel-system/#multiport-fuel-injection-mfi-generic-scan-tool-18l-5v-turbo-amb__fuel-pump-fp-relay-j17-and) .
4. Parking brake engaged.
5. Vehicles with automatic transmission: Selector lever in position "P" or "N".
6. Electrical consumers switched off (radiator fan must NOT run during test).
7. A/C switched off.
8. Coolant temperature at least 80 °C; "PID 05: Coolant temperature". See «MODE 1: CHECK MEASURED VALUES»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb__mode-1-check-measured-values) .
9. Ignition switched off.

Note. Voltage is supplied to Mass Air Flow (MAF) sensor from Fuel Pump (FP) relay. Use only gold-plated terminals when servicing terminals in harness connector of Mass Air Flow (MAF) sensor.

Checking function

1. Connect diagnostic tester. See «CONNECT DIAGNOSTIC TESTER»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb) .
2. Start engine and let run at idle.
3. In diagnostic function "33 - OBD", select "Mode 1: Checking measured values."
4. Select the desired measuring value "PID 16: Air flow quantity at Mass Air Flow (MAF) sensor". Specified value: 2.0 ... 4.5 g/s
5. End diagnosis and switch ignition off.

If the specified value is not reached

1. Check intake air system for leaks (false air). See «INTAKE SYSTEM, CHECKING FOR LEAKS (FALSE AIR)»(/audi/a4/b7-2004-2009/remont/fuel-system/#multiport-fuel-injection-mfi-generic-scan-tool-18l-5v-turbo-amb__intake-system-checking-for-leaks-false) .
2. Check voltage supply and wire connections. See «CHECKING VOLTAGE SUPPLY»(/audi/a4/b7-2004-2009/remont/fuel-system/#multiport-fuel-injection-mfi-generic-scan-tool-18l-5v-turbo-amb) .

If the specified value is exceeded

1. Eliminate engine load via additional equipment (A/C system/power-assisted steering/alternator).
2. Check voltage supply and wire connections. See «CHECKING VOLTAGE SUPPLY»(/audi/a4/b7-2004-2009/remont/fuel-system/#multiport-fuel-injection-mfi-generic-scan-tool-18l-5v-turbo-amb) .

Scheme 137

1. Disconnect harness connector -arrow- at Mass Air Flow (MAF) sensor.
2. Connect multimeter for voltage measurement as follows. MASS AIR FLOW SENSOR TERMINAL 2 VOLTAGE Harness connector Terminal Measure to 2 Engine Ground (GND)
3. Operate starter briefly. Specified value: approx. battery voltage
4. Switch ignition off.

If specified value is not obtained

1. Check wire connection from harness connector terminal 2 to Fuel Pump (FP) Relay -J17- via fuse for open circuit according to wiring diagram. Specified value: Wire resistance max 1.5ohms
2. If necessary, repair wire connection.

If voltage supply is OK

Check Ground (GND) activation

1. Connect multimeter between terminal 2 and 3 of harness connector for voltage measurement.
2. Operate starter briefly. Specified value: approx. battery voltage
3. Switch ignition off.

If specified value is not obtained

1. Check wire connections. See «CHECKING WIRE CONNECTIONS»(/audi/a4/b7-2004-2009/remont/fuel-system/#multiport-fuel-injection-mfi-generic-scan-tool-18l-5v-turbo-amb__checking-wire-connections) .
2. Connect multimeter between terminal 3 and 4 of harness connector for voltage measurement.
3. Switch ignition on. Specified value: about 5 V
4. Switch ignition off.

If specified value is not obtained

Checking wire connections

Note. Signal wire is also checked during wire test.

Scheme 138

1. Connect test box to wiring harness of Engine Control Module (ECM). See «TEST BOX, CONNECTING FOR WIRING AND COMPONENT TEST»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb) ; ECM is not connected.
2. Check the following wire connections for open circuit according to wiring diagram: MASS AIR FLOW SENSOR TERMINALS & SOCKETS Harness connector Terminal Test box Socket 3 27 4 53 5 29 Specified value: Wire resistance max 1.5 ohms
3. Also check wires for short circuit to each other as well as to B+ and Ground (GND). Specified value: INFINITY ohms (no continuity)
4. If necessary, repair wire connection.

If no malfunctions are detected

1. Replace Mass Air Flow (MAF) sensor -G70-. See item 25 .

After repair work, the following work steps must be performed in the mentioned sequence

1. Check DTC memory. See «MODE 3: CHECK DTC MEMORY»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb__mode-3-check-dtc-memory) .
2. If necessary, erase DTC memory. See «MODE 4: RESET/ERASE DIAGNOSTIC DATA»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb__mode-4-reseterase-diagnostic-data) .
3. Generate readiness code. See «READINESS CODE, GENERATING»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb) .

1. End diagnosis and switch ignition off.

Throttle Valve Control Module -J338-, checking

Component location. See OVERVIEW OF COMPONENT LOCATIONS .

The following components are located in the housing for the throttle valve control module

1. Throttle drive (power accelerator actuation) -G186-. (This is an electric motor that is activated by the ECM. This electric motor opens the throttle valve against spring pressure.)
2. Angle sensor -1- for throttle drive (power accelerator actuation) -G187
3. Angle sensor -2- for throttle drive (power accelerator actuation) -G188- NOTE: The housing for the throttle valve control module must not be opened. The angle sensors are designed as potentiometers (variable resistances). They communicate the position of the throttle valve to the Engine Control Module (ECM) fully independent of each other.

1. VAG1526A hand multimeter
2. VAG1594A connector test kit
3. VAG1598/31 test box

1. Fuses for engine electronics OK See appropriate System Wiring Diagram article.
2. Ground (GND) connections at engine and transmission OK
3. Battery voltage at least 12.5 V
4. Parking brake engaged.
5. Vehicles with automatic transmission: Selector lever in position "P" or "N".
6. Electrical consumers switched off (radiator fan must NOT run during test).
7. A/C switched off.
8. Coolant temperature at least 80 °C; "PID 05: Coolant temperature". See «MODE 1: CHECK MEASURED VALUES»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb__mode-1-check-measured-values) . NOTE: Use only gold-plated terminals when servicing terminals in harness connector of throttle valve control module.

1. Connect diagnostic tester. See «CONNECT DIAGNOSTIC TESTER»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb) .
2. Switch ignition on.
3. In diagnostic function "33 - OBD", select "Mode 1: Checking measured values."
4. Select the desired measuring value "PID 17: Throttle valve position (absolute)." Specified value: 12 ... 16 %
5. Slowly depress accelerator pedal completely. Specified value: The percentage display must increase uniformly
6. Hold accelerator pedal fully depressed; in vehicles with automatic transmission, do not depress beyond the kickdown point when doing this. Specified value: 84 ... 88 %
7. Switch ignition off.

If specified values are not obtained

1. Check voltage supply and wire connections of throttle valve control module. See «CHECKING VOLTAGE SUPPLY»(/audi/a4/b7-2004-2009/remont/fuel-system/#multiport-fuel-injection-mfi-generic-scan-tool-18l-5v-turbo-amb) . Pay particular attention to harness connectors that could be loose or corroded.
2. Check Throttle Position (TP) sensor. See «THROTTLE POSITION (TP) SENSOR, CHECKING»(/audi/a4/b7-2004-2009/remont/fuel-system/#fuel-supply-generic-scan-tool-18l-5v-turbo-amb) .

Scheme 139

1. Disconnect electrical harness connector at throttle valve control module.
2. Switch ignition on.
3. Connect multimeter for voltage measurement as follows: THROTTLE VALVE CONTROL MODULE TERMINAL VOLTAGE Harness connector Terminal Specified value 2 + Ground (GND) about 5 V 2 + 6 about 5 V
4. Switch ignition off.

If specified values are not obtained

Scheme 140

1. Connect test box to wiring harness of Engine Control Module (ECM). See «TEST BOX, CONNECTING FOR WIRING AND COMPONENT TEST»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb) ; ECM is not connected.
2. Check the following wire connections for open circuit according to wiring diagram: THROTTLE VALVE CONTROL MODULE TERMINALS & SOCKETS Harness connector Terminal Test box Socket 1 92 2 83 3 117 4 84 5 118 6 91 Specified value: Wire resistance max 1.5ohms
3. Also check wires for short circuit to each other as well as to B+ and Ground (GND). Specified value: INFINITY ohms (no continuity)
4. If necessary, repair wire connection.

If no malfunction is detected in the wiring and if the voltage supply was OK

1. Replace the throttle valve control module. See item 16 .
2. After replacing the throttle valve control module, it must be adapted. For this purpose switch on ignition for at least 30 seconds without starting engine or depressing accelerator pedal.
3. Switch ignition off. Engine Control Module (ECM) now requires approx. 3 seconds to store the learned value. At this time, the ignition must not be switched on again

After repair work, the following work steps must be performed in the mentioned sequence

1. Check DTC memory. See «MODE 3: CHECK DTC MEMORY»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb__mode-3-check-dtc-memory) .
2. If necessary, erase DTC memory. See «MODE 4: RESET/ERASE DIAGNOSTIC DATA»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb__mode-4-reseterase-diagnostic-data) .
3. Generate readiness code. See «READINESS CODE, GENERATING»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb) .

1. End diagnosis and switch ignition off.

Engine Speed (RPM) Sensor -G28-, checking

Note. The engine speed (RPM) sensor detects RPM and reference marks. The engine cannot be started without a signal from the engine speed (RPM) sensor -G28-. If the engine speed (RPM) sensor -G28- signal fails while the engine is running, the engine will stop immediately.

1. VAG1526A hand multimeter
2. VAG1594A connector test kit
3. VAG1598/31 test box

Test requirement

1. Ignition switched off.

Component location. See OVERVIEW OF COMPONENT LOCATIONS .

1. Before performing test, check sensor for proper installation and proper fitting.
2. Disconnect harness connector at Engine Speed (RPM) Sensor -G28- (item 3).

Note. Coolant reservoir screw (arrow) must be removed and coolant reservoir must be placed to the side in order to access harness connector. The coolant hoses remain connected.

Scheme 141

1. Connect multimeter between terminal 2 and 3 for resistance measurement. Specified value: 730 ... 1000 ohms NOTE: Resistance value of the engine speed (RPM) sensor is based on a temperature of 20 °C. Resistance increases as temperature increases.

If specified value is not obtained

1. Replace Engine Speed (RPM) sensor. See item 6 .

If specified value is obtained

1. Connect multimeter to terminals 2 and 1 (shielding) and to terminals 3 and 1 (shielding) for resistance measurement. Specified value: each INFINITY ohms (no continuity)

If specified value is not obtained

1. Replace Engine Speed (RPM) sensor. See item 6 .

If specified value is obtained

Scheme 142

1. Connect test box to wiring harness of Engine Control Module (ECM). See «TEST BOX, CONNECTING FOR WIRING AND COMPONENT TEST»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb) ; ECM is not connected.
2. Check the following wire connections for open circuit according to wiring diagram: ENGINE SPEED SENSOR TERMINALS & SOCKETS Harness connector Terminal Test box Socket 1 (shielding) 108 2 (Ground -GND-) 90 3 (signal) 82 Specified value: Wire resistance max 1.5 ohms
3. Also check wires for short circuit to each other as well as to B+ and Ground (GND). Specified value: INFINITY ohms (no continuity)
4. If necessary, repair wire connection.

If no malfunctions are detected

1. Replace Engine Control Module (ECM).

After repair work, the following work steps must be performed in the mentioned sequence

1. Check DTC memory. See «MODE 3: CHECK DTC MEMORY»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb__mode-3-check-dtc-memory) .
2. If necessary, erase DTC memory. See «MODE 4: RESET/ERASE DIAGNOSTIC DATA»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb__mode-4-reseterase-diagnostic-data) .
3. Generate readiness code. See «READINESS CODE, GENERATING»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb) .

1. End diagnosis and switch ignition off.

Intake Air Temperature (IAT) sensor -G42-, checking

Recommended special tools and equipment

1. VAG1526A hand multimeter
2. VAG1594A connector test kit
3. VAG1598/31 test box

Component location. See OVERVIEW OF COMPONENT LOCATIONS .

1. Fuses for engine electronics OK See appropriate System Wiring Diagram article.
2. Ignition switched off.

1. Connect diagnostic tester. See «CONNECT DIAGNOSTIC TESTER»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb) .
2. Start engine and let run at idle.
3. In diagnostic function "33 - OBD", select "Mode 1: Checking measured values."
4. Select the desired measuring value "PID 15: Intake air temperature". Specified value: approx. ambient temperature NOTE: If a temperature is indicated which differs greatly from ambient temperature of sensor, check sensor and sensor wires for contact resistances and open circuit.
5. End diagnosis and switch ignition off.

If indications do not resemble description

1. Connect multimeter at sensor for resistance measurement.

Specified values

INTAKE AIR TEMPERATURE SENSOR SPECIFIED VALUES

If specified values are not obtained

1. Replace Intake Air Temperature (IAT) sensor. See item 17 .

Scheme 143

1. Connect test box to wiring harness of Engine Control Module (ECM). See «TEST BOX, CONNECTING FOR WIRING AND COMPONENT TEST»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb) ; ECM is not connected.
2. Check the following wire connection for open circuit according to wiring diagram: INTAKE AIR TEMPERATURE SENSOR TERMINALS & SOCKETS Harness connector Terminal Test box Socket 1 85 2 108 Specified value: Wire resistance max 1.5ohms
3. Also check wires for short circuit to each other as well as to B+ and Ground (GND). Specified value: INFINITY ohms (no continuity)
4. If necessary, repair wire connection.

If no malfunctions are found in wires

1. Replace Mass Air Flow (MAF) sensor -G70-. See item 25 .

After repair work, the following work steps must be performed in the mentioned sequence

1. Check DTC memory. See «MODE 3: CHECK DTC MEMORY»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb__mode-3-check-dtc-memory) .
2. If necessary, erase DTC memory. See «MODE 4: RESET/ERASE DIAGNOSTIC DATA»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb__mode-4-reseterase-diagnostic-data) .
3. Generate readiness code. See «READINESS CODE, GENERATING»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb) .

1. End diagnosis and switch ignition off.

1. VAG1526A hand multimeter
2. VAG1594A connector test kit
3. VAG1598/31 test box

Component location. See OVERVIEW OF COMPONENT LOCATIONS .

1. Fuses for engine electronics OK See appropriate System Wiring Diagram article.
2. Engine cold

1. Connect diagnostic tester. See «CONNECT DIAGNOSTIC TESTER»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb) .
2. Switch ignition on.
3. In diagnostic function "33 - OBD", select "Mode 1: Checking measured values."
4. Select the desired measuring value "PID 05: Coolant temperature". Specified value: approx. ambient temperature NOTE: If a temperature is indicated which differs greatly from ambient temperature of sensor, check sensor and sensor wires for contact resistances and open circuit.
5. Start engine and let run at idle. Specified value: Temperature value must rise evenly NOTE: The temperature increases in increments of 1.0 °C. If the engine shows problems in certain temperature ranges and if the temperature does not climb uniformly, the temperature signal is intermittent and the sensor should be replaced.
6. End diagnosis and switch ignition off.

If indications do not resemble description

1. Disconnect electrical harness connector at Engine Coolant Temperature (ECT) Sensor -G2-/-G62- (arrow).
2. Connect multimeter between terminal C and D of sensor for resistance measurement. Range A displays resistance values for the temperature range of 0...50 °C, range B displays resistance values for the temperature range of 50...100 °C.

Read-out examples

1. 30 °C corresponds to a resistance of 1500 to 2000ohms
2. 80 °C corresponds to a resistance of 275 to 375ohms

If specified value is not obtained

1. Replace Engine Coolant Temperature (ECT) Sensor -G62-. See item 5 .

If specified value is obtained

Scheme 144

1. Connect test box to wiring harness of Engine Control Module (ECM). See «TEST BOX, CONNECTING FOR WIRING AND COMPONENT TEST»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb) ; ECM is not connected.
2. Check the following wire connections for open circuit according to wiring diagram: INTAKE AIR TEMPERATURE SENSOR TERMINALS & SOCKETS Harness connector Terminal Test box Socket 3 108 4 (signal) 93 Specified value: Wire resistance max 1.5ohms
3. Also check wires for short circuit to each other as well as to B+ and Ground (GND). Specified value: INFINITY ohms (no continuity)
4. If necessary, repair wire connection.

If no malfunctions are found in wires

1. Replace Engine Control Module (ECM).

After repair work, the following work steps must be performed in the mentioned sequence

1. Check DTC memory. See «MODE 3: CHECK DTC MEMORY»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb__mode-3-check-dtc-memory) .
2. If necessary, erase DTC memory. See «MODE 4: RESET/ERASE DIAGNOSTIC DATA»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb__mode-4-reseterase-diagnostic-data) .
3. Generate readiness code. See «READINESS CODE, GENERATING»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb) . End diagnosis and switch ignition off.

1. VAG1526A hand multimeter
2. VAG1594A connector test kit
3. VAG1598/31 test box

1. Fuse for wastegate bypass regulator valve OK See appropriate System Wiring Diagram article.
2. Fuel Pump (FP) Relay OK; checking. See «FUEL PUMP (FP) RELAY -J17- AND ACTIVATION, CHECKING»(/audi/a4/b7-2004-2009/remont/fuel-system/#multiport-fuel-injection-mfi-generic-scan-tool-18l-5v-turbo-amb__fuel-pump-fp-relay-j17-and) .
3. Ignition switched off.

Note. Voltage for Wastegate Bypass Regulator Valve -N75- is supplied via the fuel pump relay.

1. Disconnect electrical harness connector at Wastegate Bypass Regulator Valve -N75-.

1. Connect multimeter at valve for resistance measurement. Specified value: 25... 35 ohms
2. Replace Wastegate Bypass Regulator Valve -N75-.

If specified value is obtained

1. Connect multimeter between terminal 1 and 2 for voltage measurement.
2. Operate starter briefly. Specified value: approx. battery voltage

If there is no voltage

1. Connect multimeter for voltage measurement as follows: WASTEGATE BYPASS REGULATOR VALVE TERMINAL 1 VOLTAGE Harness connector Terminal Measure to 1 Engine Ground (GND)
2. Operate starter briefly. Specified value: approx. battery voltage
3. Switch ignition off.

If there is no voltage again

1. Check wire connection from harness connector terminal 1 to Fuel Pump (FP) Relay -J17- via fuse for open circuit according to wiring diagram. Specified value: Wire resistance max 1.5 ohms
2. If necessary, repair wire connection.

If voltage supply is OK

Scheme 145

1. Connect multimeter for voltage measurement as follows: WASTEGATE BYPASS REGULATOR VALVE TERMINAL 2 VOLTAGE Harness connector Terminal Measure to 2 B+
2. Operate starter briefly. Specified value: approx. battery voltage
3. Switch ignition off.

If specified value is not obtained

Scheme 146

1. Connect test box to wiring harness of Engine Control Module (ECM). See «TEST BOX, CONNECTING FOR WIRING AND COMPONENT TEST»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb) ; ECM is not connected.
2. Check the following wire connection for open circuit according to wiring diagram: WASTEGATE BYPASS REGULATOR VALVE TERMINAL 2 & SOCKET 104 Harness connector Terminal Test box Socket 2 104 Specified value: Wire resistance max 1.5 ohms
3. Also check the wire for short circuit to B+ and Ground (GND). Specified value: INFINITY ohms (no continuity)
4. If necessary, repair wire connection.
5. Replace Engine Control Module (ECM).

After repair work, the following work steps must be performed in the mentioned sequence

1. Check DTC memory. See «MODE 3: CHECK DTC MEMORY»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb__mode-3-check-dtc-memory) .
2. If necessary, erase DTC memory. See «MODE 4: RESET/ERASE DIAGNOSTIC DATA»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb__mode-4-reseterase-diagnostic-data) .
3. Generate readiness code. See «READINESS CODE, GENERATING»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb) .

1. End diagnosis and switch ignition off.

1. VAG1526A hand multimeter
2. VAG1594A connector test kit
3. VAG1598/31 test box

1. Disconnect connector (arrow) at charge air pressure sensor.

1. Connect multimeter between terminal 1 and 3 of harness connector for voltage measurement.
2. Switch ignition on. Specified value: about 5 V
3. Switch ignition off.

If specified value is not obtained

Scheme 147

1. Connect test box to wiring harness of Engine Control Module (ECM). See «TEST BOX, CONNECTING FOR WIRING AND COMPONENT TEST»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb) ; ECM is not connected.
2. Check the following wire connections for open circuit and short circuit to Ground (GND) and B+: CHARGE AIR PRESSURE SENSOR TERMINALS & SOCKETS Harness connector Terminal Test box Socket 1 108 3 98
3. Repair open circuit in wiring or short circuit if necessary.

If specified value is obtained

Checking signal wire

1. Connect harness connector at charge air pressure sensor.
2. Connect multimeter to socket 101 and socket 108 of test box for voltage measurement.
3. Start engine and let run at idle. Specified value: about 1.90 V
4. Bring engine to RPM by depressing pedal suddenly. Specified value: 2.00 ... 3.00 V

If specified values are not obtained

Scheme 148

1. Check the following wire connection for open circuit and short circuit to Ground (GND) and B+: CHARGE AIR PRESSURE SENSOR TERMINAL 4 & SOCKET 101 Harness connector Terminal Test box Socket 4 101 Specified value: Wire resistance max 1.5 ohms
2. Also check the wire for short circuit to B+ and Ground (GND). Specified value: INFINITY ohms (no continuity)
3. If necessary, repair wire connection.

If no malfunctions are found in wire

1. Replace the Charge Air Pressure Sensor -G31-.

After repair work, the following work steps must be performed in the mentioned sequence

1. Check DTC memory. See «MODE 3: CHECK DTC MEMORY»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb__mode-3-check-dtc-memory) .
2. If necessary, erase DTC memory. See «MODE 4: RESET/ERASE DIAGNOSTIC DATA»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb__mode-4-reseterase-diagnostic-data) .
3. Generate readiness code. See «READINESS CODE, GENERATING»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb) .

1. End diagnosis and switch ignition off.

Clutch vacuum vent valve switch -F36-, checking

Recommended special tools and equipment

1. VAG1526A hand multimeter
2. V.A.G 1527 B Voltage Tester
3. VAG1594A connector test kit
4. VAG1598/31 test box

Note. This signal helps prevent excessive RPM oscillations and tip-in shocks when clutch is disengaged and is required for the cruise control system.

1. Ignition switched off.

Check switch

1. Remove driver-side storage compartment: See «DRIVER-SIDE STORAGE COMPARTMENT (WITH AND WITHOUT KNEE BOLSTER), ASSEMBLY OVERVIEW»(ref-197206-S03507421422005101300000) (except Cabriolet), or «DRIVER'S STORAGE COMPARTMENT (VEHICLES WITH AND WITHOUT KNEE BOLSTER), ASSEMBLY OVERVIEW»(ref-197209-S29048734852005101300000) (Cabriolet).
2. Disconnect electrical harness connector at clutch vacuum vent valve switch -1-.
3. Connect multimeter between terminal 2 and 3 for resistance measurement. Specified value: approx. 0 ohms
4. Depress clutch pedal. Specified value: INFINITY ohms (no continuity)

If specified value is not obtained

1. Replace Clutch vacuum vent valve switch.

If specified values are obtained

Scheme 149

1. Connect e.g. V.A.G 1527 B voltage tester as follows: CLUTCH VACUUM VENT VALVE SWITCH TERMINAL 3 VOLTAGE Harness connector Terminal Measure to 3 Chassis Ground (GND)
2. Switch ignition on. LED must light up.
3. Switch ignition off.

If LED does not light up

1. Check the wire connection for open circuit. Specified value: Wire resistance max 1.5 ohms
2. If necessary, repair wire connection.

If LED lights up

Scheme 150

1. Connect test box to wiring harness of Engine Control Module (ECM). See «TEST BOX, CONNECTING FOR WIRING AND COMPONENT TEST»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb) ; ECM is not connected.
2. Check the following wire connection for open circuit according to wiring diagram: CLUTCH VACUUM VENT VALVE SWITCH TERMINAL 2 & SOCKET 39 Harness connector Terminal Test box Socket 2 39 Specified value: Wire resistance max 1.5 ohms
3. Also check the wire for short circuit to B+ and Ground (GND). Specified value: INFINITY ohms (no continuity)
4. If necessary, repair wire connection.

After repair work, the following work steps must be performed in the mentioned sequence

1. Check DTC memory. See «MODE 3: CHECK DTC MEMORY»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb__mode-3-check-dtc-memory) .
2. If necessary, erase DTC memory. See «MODE 4: RESET/ERASE DIAGNOSTIC DATA»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb__mode-4-reseterase-diagnostic-data) .
3. Generate readiness code. See «READINESS CODE, GENERATING»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb) .

1. End diagnosis and switch ignition off.

1. VAG1526A hand multimeter
2. VAG1594A connector test kit
3. VAG1598/31 test box

1. Fuse for valve for camshaft adjustment is OK See appropriate System Wiring Diagram article.
2. Motronic Engine Control Module (ECM) Power Supply Relay -J271- OK; checking. See «CHECK MOTRONIC ENGINE CONTROL MODULE (ECM) POWER SUPPLY RELAY -J271- AND ACTIVATION»(/audi/a4/b7-2004-2009/remont/fuel-system/#multiport-fuel-injection-mfi-generic-scan-tool-18l-5v-turbo-amb__check-motronic-engine-control-module-ecm) .
3. Ignition switched off.

Note. Voltage for valve for camshaft adjustment is supplied via Motronic Engine Control Module (ECM) Power Supply Relay -J271-.

1. Disconnect electrical harness connector (arrow) at Valve -1- for camshaft adjustment -N205-.

1. Connect multimeter at valve for resistance measurement. Specified value: 10 ... 18 ohms

If specified value is not obtained

1. Replace valve for camshaft adjustment. See «CAMSHAFT ADJUSTMENT VALVE, CHECKING»(ref-197056-S37823425792005101100000) .

If specified value is obtained

1. Connect multimeter between terminal 1 and 2 for voltage measurement.
2. Operate starter briefly. Specified value: approx. battery voltage

If there is no voltage

1. Connect multimeter for voltage measurement as follows: CAMSHAFT ADJUSTMENT VALVE TERMINAL 1 VOLTAGE Harness connector Terminal Measure to 1 Engine Ground (GND)
2. Switch ignition on. Specified value: approx. battery voltage
3. Switch ignition off.

If there is no voltage again

1. Check wire connection from terminal 1 of harness connector via fuse to Motronic Engine Control Module (ECM) Power Supply Relay -J271- for open circuit according to wiring diagram. Specified value: Wire resistance max 1.5 ohms
2. If necessary, repair wire connection.

If voltage supply is OK

Scheme 151

1. Connect test box to wiring harness of Engine Control Module (ECM). See «TEST BOX, CONNECTING FOR WIRING AND COMPONENT TEST»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb) ; ECM is not connected.
2. Check the following wire connections for open circuit according to wiring diagram: CAMSHAFT ADJUSTMENT VALVE TERMINAL 2 & SOCKET 115 Harness connector Terminal Test box Socket 2 115 Specified value: Wire resistance max 1.5 ohms
3. Also check wires for short circuit to each other as well as to B+ and Ground (GND). Specified value: INFINITY ohms (no continuity)
4. If necessary, repair wire connection.

If no malfunctions are found in wires

1. Replace Engine Control Module (ECM).

If no malfunctions are detected

1. Replace mechanical camshaft adjuster. See «CAMSHAFTS AND CAMSHAFT ADJUSTER, REMOVING AND INSTALLING»(ref-197056-S38829219262005101100000) .

After repair work, the following work steps must be performed in the mentioned sequence

1. Check DTC memory. See «MODE 3: CHECK DTC MEMORY»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb__mode-3-check-dtc-memory) .
2. If necessary, erase DTC memory. See «MODE 4: RESET/ERASE DIAGNOSTIC DATA»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb__mode-4-reseterase-diagnostic-data) .
3. Generate readiness code. See «READINESS CODE, GENERATING»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb) .

1. End diagnosis and switch ignition off.

Fuel Pump (FP) Relay -J17- and activation, checking

Recommended special tools and equipment

1. VAG1526A hand multimeter
2. VAG1594A connector test kit
3. VAG1598/31 test box

Voltage is supplied to the Fuel Pump (FP) and several components of the injection system via the Fuel Pump (FP) Relay -J17-.

Engine must be turning for Fuel Pump (FP) Relay -J17- to close. This means that the relay does not receive Ground (GND) (via ECM) until the ECM recognizes RPM signals.

1. Battery voltage at least 12.5 V
2. Ignition switched off.

Function test of Fuel Pump (FP) relay

1. Remove driver-side storage compartment: See «DRIVER-SIDE STORAGE COMPARTMENT (WITH AND WITHOUT KNEE BOLSTER), ASSEMBLY OVERVIEW»(ref-197206-S03507421422005101300000) (except Cabriolet), or «DRIVER'S STORAGE COMPARTMENT (VEHICLES WITH AND WITHOUT KNEE BOLSTER), ASSEMBLY OVERVIEW»(ref-197209-S29048734852005101300000) (Cabriolet).
2. Connect test box to wiring harness of Engine Control Module (ECM). See «TEST BOX, CONNECTING FOR WIRING AND COMPONENT TEST»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb) ; ECM is not connected.
3. Bridge terminals 1 and 65 at test box using wires e.g. from V.A.G 1594 A adapter test kit.
4. Switch ignition on.

1. Fuel Pump (FP) relay (position 1, at 9-pin relay carrier in driver's footwell, left) must trigger and Fuel Pump (FP) must run.

1. If Fuel Pump (FP) runs: Check voltage supply of Fuel Pump (FP) relay. See «CHECK VOLTAGE SUPPLY OF FUEL PUMP (FP) RELAY»(/audi/a4/b7-2004-2009/remont/fuel-system/#multiport-fuel-injection-mfi-generic-scan-tool-18l-5v-turbo-amb) . Checking activation of Fuel Pump (FP) relay. See «CHECKING ACTIVATION OF FUEL PUMP (FP) RELAY»(/audi/a4/b7-2004-2009/remont/fuel-system/#multiport-fuel-injection-mfi-generic-scan-tool-18l-5v-turbo-amb) .
2. If Fuel Pump (FP) does not run: Check voltage supply for Fuel Pump (FP) and components (via Fuel Pump -FP- relay). See «CHECK VOLTAGE SUPPLY FOR FUEL PUMP (FP) AND COMPONENTS»(/audi/a4/b7-2004-2009/remont/fuel-system/#multiport-fuel-injection-mfi-generic-scan-tool-18l-5v-turbo-amb__check-voltage-supply-for-fuel-pump) .

Scheme 152

1. Remove Fuel Pump (FP) relay.
2. Connect multimeter for voltage measurement as follows. FUEL PUMP RELAY TERMINAL 1 VOLTAGE 9-pin relay carrier in driver's footwell, left side, position 1 Terminal Measure to 1 Chassis Ground (GND) Specified value: approx. battery voltage
3. Connect multimeter for voltage measurement as follows: FUEL PUMP RELAY TERMINAL 3 VOLTAGE 9-pin relay carrier in driver's footwell, left side, position 1 Terminal Measure to 3 Chassis Ground (GND)
4. Switch ignition on. Specified value: approx. battery voltage
5. Switch ignition off.

If specified values are not obtained

1. Check wire connections for open circuit according to wiring diagram. Specified value: Wire resistance max 1.5 ohms

If specified values are obtained

Scheme 153

1. Remove cable bridge.
2. Remove Fuel Pump (FP) relay.
3. Connect test box to wiring harness of Engine Control Module (ECM). See «TEST BOX, CONNECTING FOR WIRING AND COMPONENT TEST»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb) ; ECM is not connected.
4. Check the following wire connection for open circuit according to wiring diagram: FUEL PUMP RELAY TERMINAL 5 & SOCKET 65 9-pin relay carrier in driver's footwell, left side, position 1 Terminal Test box Socket 5 65 Specified value: Wire resistance max 1.5 ohms
5. Also check the wire for short circuit to B+ and Ground (GND). Specified value: INFINITY ohms (no continuity)
6. If necessary, repair wire connection.

If no malfunctions are detected

1. Replace Fuel Pump (FP) Relay -J17-.
2. Replace Engine Control Module (ECM).

Check voltage supply for Fuel Pump (FP) and components

1. Remove fuses S228, S232, and S234 (positions 28, 32, and 34) from fuse holder.
2. Connect multimeter for voltage measurement to Ground (GND) and to one terminal of the following fuses in the fuse holder.
3. Operate starter briefly. FUEL PUMP RELAY FUSES Fuse Specified value at one of the terminals S228 approx. battery voltage S232 approx. battery voltage S234 approx. battery voltage

If specified values are not obtained

1. Repeat test at another terminal of fuse socket.

If specified values are not obtained again

1. Check wire connections for open circuit according to wiring diagram. Specified value: Wire resistance max 1.5 ohms

If no malfunctions are detected

1. Replace Fuel Pump (FP) Relay -J17-.
2. Re-insert the fuses.

After repair work, the following work steps must be performed in the mentioned sequence

1. Check DTC memory. See «MODE 3: CHECK DTC MEMORY»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb__mode-3-check-dtc-memory) .
2. If necessary, erase DTC memory. See «MODE 4: RESET/ERASE DIAGNOSTIC DATA»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb__mode-4-reseterase-diagnostic-data) .
3. Generate readiness code. See «READINESS CODE, GENERATING»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb) .

1. End diagnosis and switch ignition off.

System pressure and residual pressure, checking

Note. Fuel pressure regulator is integrated in fuel filter (under fuel tank) and cannot be replaced individually.

1. Fuel INJ. Pressure Gauge Set V.A.G 1318 with adapters V.A.G 1318/6 and V.A.G 1318/7

1. Fuel Pump (FP) Relay OK; checking. See «FUEL PUMP (FP) RELAY -J17- AND ACTIVATION, CHECKING»(/audi/a4/b7-2004-2009/remont/fuel-system/#multiport-fuel-injection-mfi-generic-scan-tool-18l-5v-turbo-amb__fuel-pump-fp-relay-j17-and) .
2. Delivery quantity of Fuel Pump (FP) OK; check. See «DELIVERY QUANTITY OF FUEL PUMP (FP), CHECKING»(/audi/a4/b7-2004-2009/remont/fuel-system/#fuel-supply-generic-scan-tool-18l-5v-turbo-amb) for FWD up to 06.2003, or «DELIVERY QUANTITY OF FUEL PUMP (FP), CHECKING»(/audi/a4/b7-2004-2009/remont/fuel-system/#fuel-supply-generic-scan-tool-18l-5v-turbo-amb) for FWD as of 07.2003, or «DELIVERY QUANTITY OF FUEL PUMP (FP), CHECKING»(/audi/a4/b7-2004-2009/remont/fuel-system/#fuel-supply-generic-scan-tool-18l-5v-turbo-amb) for AWD up to 06.2003, or «DELIVERY QUANTITY OF FUEL PUMP (FP), CHECKING»(/audi/a4/b7-2004-2009/remont/fuel-system/#fuel-supply-generic-scan-tool-18l-5v-turbo-amb) for AWD as of 07.2003.
3. Fuel filter OK
4. Parking brake engaged.
5. Vehicles with automatic transmission: Selector lever in position "P" or "N".
6. Electrical consumers switched off (radiator fan must NOT run during test).
7. A/C switched off.
8. Ignition switched off.

Checking system pressure

1. Remove engine cover (arrows).
2. Open fuel filler flap briefly (pressure release). CAUTION: Work on the fuel system must only be performed when engine is cold! Fuel system is under pressure! Before opening system, place rags around the connection point. Then release pressure by carefully loosening connection.
3. Open threaded connection -1- and catch escaping fuel using a rag.
4. Connect V.A.G 1318 pressure gauge in supply line using adapters 1318/6 and 1318/7.
5. Open shut-off valve of pressure gauge. The lever points in the direction of flow.
6. Start engine and let run at idle.
7. Measure fuel pressure. Specified value: approx. 4.0 bar positive pressure
8. Switch ignition off.
9. Check for proper seal and residual pressure by observing pressure drop on pressure gauge. After 10 minutes, there must be at least 2.5 bar positive pressure

If residual pressure sinks below 2.5 bar positive pressure

1. Start engine and let run at idle.
2. Wait until pressure has risen, and then switch off ignition. Simultaneously close shut-off valve of VAG1318 pressure gauge (lever perpendicular to direction of flow -arrow-).
3. Observe pressure drop on pressure gauge.

If pressure drops again

1. Check pressure gauge for proper seal.
2. Check line connections and fuel injectors for proper seal.

If pressure does not drop now

1. Check pressure regulator in fuel filter: Vehicles with Front Wheel Drive (FWD). See «CHECKING FUEL PRESSURE REGULATOR - VEHICLES WITH FRONT WHEEL DRIVE (FWD)»(/audi/a4/b7-2004-2009/remont/fuel-system/#multiport-fuel-injection-mfi-generic-scan-tool-18l-5v-turbo-amb) . Vehicles with All Wheel Drive (AWD). See «CHECKING FUEL PRESSURE REGULATOR - VEHICLES WITH ALL WHEEL DRIVE (AWD)»(/audi/a4/b7-2004-2009/remont/fuel-system/#multiport-fuel-injection-mfi-generic-scan-tool-18l-5v-turbo-amb__checking-fuel-pressure-regulator-vehicles) .

Sedan

1. Remove luggage compartment lining. See «LUGGAGE COMPARTMENT SIDE TRIM, ASSEMBLY OVERVIEW»(ref-197207-S26740012742005101300000) .
2. Push forward the right backrest of rear seat, if necessary.

Avant

1. Remove left 1/3 backrest. See «LEFT 1/3 BACKREST, REMOVING AND INSTALLING»(ref-197208-S04757838202005101400000) .
2. Remove left side trim in luggage compartment and dirt tray. See «SIDE LUGGAGE COMPARTMENT TRIM, ASSEMBLY OVERVIEW»(ref-197207-S34829070392005101300000) and «DIRT TRAY, ASSEMBLY OVERVIEW»(ref-197207-S20987383812005101300000) .

All

1. Remove cover for connector flange (arrows).
2. Disconnect fuel return line -2- (press release button).
3. Connect V.A.G 1318/17-1 adapter piece to return line.
4. Pinch off adapter piece using 3094 hose clamps. NOTE: 3094 hose clamps must not be placed directly on fuel line, otherwise it may be damaged.
5. Start engine and let run at idle.
6. Wait until pressure has risen, and then switch off ignition. Simultaneously close shut-off valve of VAG1318 pressure gauge (lever perpendicular to direction of flow -arrow-).
7. Observe pressure drop on pressure gauge. If pressure drops again, check-valve of fuel pump is leaky.
8. Replace fuel pump. See «FUEL PUMP, REMOVING AND INSTALLING»(/audi/a4/b7-2004-2009/remont/fuel-system/#fuel-supply-generic-scan-tool-18l-5v-turbo-amb__fuel-pump-removing-and-installing) .

If pressure does not drop now

1. Replace fuel filter with integrated fuel pressure regulator. Assembly is performed in the reverse order of removal, noting the following: NOTE: Before disconnecting pressure gauge, release fuel pressure by opening shut-off valve. Hold a container in front of connection for this.

Checking fuel pressure regulator - Vehicles with All Wheel Drive (AWD)

1. Remove rear seat bench. See «SEATBENCH, REMOVING AND INSTALLING»(ref-197208-S04367109682005101400000) for Cabriolet, or see «REAR SEAT BENCH, ASSEMBLY OVERVIEW»(ref-197211-S07247328082005101300000) for models other than Cabriolet.
2. Remove cover for left connector flange (arrows).
3. Disconnect fuel return line (arrow) from connector flange (left side of vehicle).
4. Connect V.A.G 1318/17-1 adapter piece to return line.
5. Pinch off adapter piece using 3094 hose clamps. NOTE: 3094 hose clamps must not be placed directly on fuel line, otherwise it may be damaged.
6. Start engine and let run at idle.
7. Wait until pressure has risen, and then switch off ignition. Simultaneously close shut-off valve of VAG1318 pressure gauge (lever perpendicular to direction of flow -arrow-).
8. Observe pressure drop on pressure gauge. If pressure drops again, check-valve of fuel pump is leaky.
9. Replace fuel pump. See «FUEL PUMP, REMOVING AND INSTALLING»(/audi/a4/b7-2004-2009/remont/fuel-system/#fuel-supply-generic-scan-tool-18l-5v-turbo-amb) for vehicles up to 06.2003 or «REMOVING AND INSTALLING FUEL PUMP»(/audi/a4/b7-2004-2009/remont/fuel-system/#fuel-supply-generic-scan-tool-18l-5v-turbo-amb) for vehicles as of 07.2003.

If pressure does not drop now

1. Replace fuel filter with integrated fuel pressure regulator.

Assembly is performed in the reverse order of removal, noting the following

Note. Before disconnecting pressure gauge, release fuel pressure by opening shut-off valve. Hold a container in front of connection for this.

After repair work, the following work steps must be performed in the mentioned sequence

1. Check DTC memory. See «MODE 3: CHECK DTC MEMORY»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb__mode-3-check-dtc-memory) .
2. If necessary, erase DTC memory. See «MODE 4: RESET/ERASE DIAGNOSTIC DATA»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb__mode-4-reseterase-diagnostic-data) .
3. Generate readiness code. See «READINESS CODE, GENERATING»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb) .

1. End diagnosis and switch ignition off.

1. VAG1526A hand multimeter
2. V.A.G 1527 B Voltage Tester
3. VAG1594A connector test kit
4. VAG1598/31 test box

1. Fuse for fuel injectors OK See appropriate System Wiring Diagram article.
2. Fuel Pump (FP) Relay OK; checking. See «FUEL PUMP (FP) RELAY -J17- AND ACTIVATION, CHECKING»(/audi/a4/b7-2004-2009/remont/fuel-system/#multiport-fuel-injection-mfi-generic-scan-tool-18l-5v-turbo-amb__fuel-pump-fp-relay-j17-and) .
3. Ignition switched off.

Note. Voltage is supplied to the fuel injectors via the Fuel Pump (FP) relay.

1. Remove engine cover (arrows).

Scheme 154

1. Disconnect harness connector at the fuel injector to be tested.
2. Connect multimeter at valve for resistance measurement. Specified value: 12 ... 13 ohms (at room temperature)

With an engine at operating temperature, the resistance increases by approx. 4 to 6 ohms.

If specified value is not obtained

1. Replace fuel injector. See «FUEL INJECTORS, REMOVING AND INSTALLING»(/audi/a4/b7-2004-2009/remont/fuel-system/#multiport-fuel-injection-mfi-generic-scan-tool-18l-5v-turbo-amb__fuel-injectors-removing-and-installing) .

If specified value is obtained

Scheme 155

1. Connect e.g. V.A.G 1527 B voltage tester as follows: FUEL INJECTOR TERMINAL 1 VOLTAGE Harness connector Terminal Measure to 1 Engine Ground (GND)
2. Operate starter briefly. LED must light up.
3. Switch ignition off.

If LED does not light up

1. Check wire connection from harness connector terminal 1 to Fuel Pump (FP) Relay -J17- via fuse for open circuit according to wiring diagram. Specified value: Wire resistance max 1.5 ohms
2. If necessary, repair wire connection.

If LED lights up

1. Internal resistance of valve OK

1. Slide back rubber grommet of fuel injector connector, but leave connector connected.
2. Connect voltage tester e.g. V.A.G 1527 B with measuring probes and connector adapters from V.A.G 1594 A between terminal 2 (signal) and terminal 1 (B+); the harness connector remains connected.
3. Operate starter briefly. LED must blink. NOTE: Voltage testers do not go out completely during low current pick-up between activations by the ECM, but rather continue to glow a little and then get slightly brighter during activation.
4. Switch ignition off.

If LED does not blink

Scheme 156

1. Connect test box to wiring harness of Engine Control Module (ECM). See «TEST BOX, CONNECTING FOR WIRING AND COMPONENT TEST»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb) ; ECM is not connected.
2. Check the following wire connections for open circuit according to wiring diagram: FUEL INJECTOR TERMINALS & SOCKETS Cylinder Fuel injector harness connector Terminal Test box Socket 1 2 96 2 2 89 3 2 97 4 2 88 Specified value: Wire resistance max 1.5 ohms
3. Also check wires for short circuit to each other as well as to B+ and Ground (GND). Specified value: INFINITY ohms (no continuity)
4. If necessary, repair wire connection.

If no malfunctions are detected

1. Replace Engine Control Module (ECM).

After repair work, the following work steps must be performed in the mentioned sequence

1. Check DTC memory. See «MODE 3: CHECK DTC MEMORY»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb__mode-3-check-dtc-memory) .
2. If necessary, erase DTC memory. See «MODE 4: RESET/ERASE DIAGNOSTIC DATA»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb__mode-4-reseterase-diagnostic-data) .
3. Generate readiness code. See «READINESS CODE, GENERATING»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb) .

1. End diagnosis and switch ignition off.

1. VAG1348/3A remote control with VAG1348/3-2 adapter cable
2. VAG1594A connector test kit
3. VAG1598/31 test box
4. V.A.G 1602 tester for quantity of injected fuel

1. Fuel pressure OK, checking. See «SYSTEM PRESSURE AND RESIDUAL PRESSURE, CHECKING»(/audi/a4/b7-2004-2009/remont/fuel-system/#multiport-fuel-injection-mfi-generic-scan-tool-18l-5v-turbo-amb__system-pressure-and-residual-pressure-checking) .
2. Ignition switched off.

Test sequence

1. Remove fuel rail including fuel injectors from intake manifold. See «FUEL INJECTORS, REMOVING AND INSTALLING»(/audi/a4/b7-2004-2009/remont/fuel-system/#multiport-fuel-injection-mfi-generic-scan-tool-18l-5v-turbo-amb__fuel-injectors-removing-and-installing) . Fuel line remains connected.
2. Connect test box to wiring harness of Engine Control Module (ECM). See «TEST BOX, CONNECTING FOR WIRING AND COMPONENT TEST»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb) ; ECM is not connected.

Checking Proper Seal

1. Bridge terminals 1 and 65 at test box using wires e.g. from V.A.G 1594 A adapter test kit.
2. Switch ignition on. Fuel Pump (FP) must run.
3. Check proper seal of fuel injectors (visual inspection). With Fuel Pump (FP) running, only 1 to 2 drops per minute may drip out per injector.
4. If fuel loss is greater, stop Fuel Pump (FP) from running (switch off ignition) and replace faulty fuel injector. See «FUEL INJECTORS, REMOVING AND INSTALLING»(/audi/a4/b7-2004-2009/remont/fuel-system/#multiport-fuel-injection-mfi-generic-scan-tool-18l-5v-turbo-amb__fuel-injectors-removing-and-installing) .

Checking Injection Quantity

1. Insert fuel injector to be tested in a measuring glass from e.g. V.A.G 1602 injection quantity test device.
2. Connect one terminal of fuel injector to engine Ground (GND) using an adapter cable and an alligator clip e.g. from VAG1594A connector test kit.
3. Connect the second terminal of fuel injector to B+ using e.g. VAG1348/3A remote control, VAG1348/3-2 adapter cable and assisting cable.
4. Bridge terminals 1 and 65 at test box using wires e.g. from V.A.G 1594 A adapter test kit.
5. Switch ignition on. Fuel Pump (FP) must run.
6. Operate remote control for 30 seconds.
7. After all three fuel injectors of one cylinder row have been activated, place measuring glasses on an even surface. Specified value for each fuel injector: 135 +/- 10 ml.
8. If measured value of one or more fuel injectors is outside of specified range, switch Fuel Pump (FP) off (switch ignition off) and replace faulty fuel injector. See «FUEL INJECTORS, REMOVING AND INSTALLING»(/audi/a4/b7-2004-2009/remont/fuel-system/#multiport-fuel-injection-mfi-generic-scan-tool-18l-5v-turbo-amb__fuel-injectors-removing-and-installing) .
9. Repeat test at fuel injectors of second cylinder row.
10. If the measured values of all fuel injectors are outside the specified range, check fuel pressure. See «SYSTEM PRESSURE AND RESIDUAL PRESSURE, CHECKING»(/audi/a4/b7-2004-2009/remont/fuel-system/#multiport-fuel-injection-mfi-generic-scan-tool-18l-5v-turbo-amb__system-pressure-and-residual-pressure-checking) . NOTE: Also check spray pattern when checking injection quantity. Spray pattern must be the same for all injectors
11. Install fuel injectors together with fuel rail. See «INSTALLING»(/audi/a4/b7-2004-2009/remont/fuel-system/#multiport-fuel-injection-mfi-generic-scan-tool-18l-5v-turbo-amb__installing) .

After repair work, the following work steps must be performed in the mentioned sequence

1. Check DTC memory. See «MODE 3: CHECK DTC MEMORY»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb__mode-3-check-dtc-memory) .
2. If necessary, erase DTC memory. See «MODE 4: RESET/ERASE DIAGNOSTIC DATA»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb__mode-4-reseterase-diagnostic-data) .
3. Generate readiness code. See «READINESS CODE, GENERATING»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb) .

1. End diagnosis and switch ignition off.

Intake system, checking for leaks (false air)

Recommended special tools and equipment

1. Engine leak detection spray G 001 800 A1

Note. The negative pressure in the intake system sucks in the leak detection spray with the false air. Leak detection spray decreases ignition quality of the fuel mixture. This causes a reduction in engine speed and a sharp increase of CO content. It is absolutely necessary to follow the safety precautions listed on the can.

1. Coolant temperature at least 80 °C; "PID 05: Coolant temperature". See «MODE 1: CHECK MEASURED VALUES»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb__mode-1-check-measured-values) .
2. Ignition switched off.

1. Connect diagnostic tester. See «CONNECT DIAGNOSTIC TESTER»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb) .
2. Start engine and let run at idle.
3. In diagnostic function "33 - OBD", select "Mode 1: Checking measured values."

Note. Bank 1 = cylinder bank 1 in direction of travel, right; Bank 2 = cylinder bank 2 in direction of travel, left.

1. Select the following measured values: PID 06 & PID 12 DIAGNOSTIC CHART PID Diagnostic text Specified value 06: Short time gasoline-air ratio bank 1 -7,00...7,00 % 12: Engine rotations per minute (RPM) 700 to 860 RPM
2. Spray intake system parts with engine leak detection spray in a systematic manner.

If engine speed drops or if the short-term gasoline-air ratio changes

1. End diagnosis and switch ignition off.
2. Check sprayed part of intake system for leaks, and repair the malfunction.

After repair work, the following work steps must be performed in the mentioned sequence

1. Check DTC memory. See «MODE 3: CHECK DTC MEMORY»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb__mode-3-check-dtc-memory) .
2. If necessary, erase DTC memory. See «MODE 4: RESET/ERASE DIAGNOSTIC DATA»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb__mode-4-reseterase-diagnostic-data) .
3. Generate readiness code. See «READINESS CODE, GENERATING»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb) .

1. End diagnosis and switch ignition off.

1. VAG1526A hand multimeter
2. VAG1594A connector test kit
3. VAG1598/31 test box

1. Fuses for engine electronics OK See appropriate System Wiring Diagram article.
2. Ground (GND) connections at engine and transmission OK
3. Oxygen sensor heater OK; check. See «OXYGEN SENSOR (O2S) HEATER -Z19- BEFORE CATALYTIC CONVERTER, CHECKING»(/audi/a4/b7-2004-2009/remont/fuel-system/#multiport-fuel-injection-mfi-generic-scan-tool-18l-5v-turbo-amb) .
4. Exhaust system free of leaks.
5. Parking brake engaged.
6. Vehicles with automatic transmission: Selector lever in position "P" or "N".
7. Electrical consumers switched off (radiator fan must NOT run during test).
8. A/C switched off.
9. Coolant temperature at least 80 °C; "PID 05: Coolant temperature". See «MODE 1: CHECK MEASURED VALUES»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb__mode-1-check-measured-values) .

Note. When selecting the diagnostic mode, the entry is always performed in "Bank 1 sensor 1". If either the V.A.G 1551/1552 Scan Tool (ST) or the VAS5051/5052 Vehicle Diagnostic, Testing and Information System is used for checking the output of oxygen sensor signals, the respective oxygen sensor can be selected by pressing buttons 1 and 2: - - Button 1 = Bank 1 sensor 1, - - Button 2 = Bank 1 sensor 2, When servicing terminals in harness connector of Heated Oxygen Sensor (HO2S), use only gold-plated terminals.

1. Connect diagnostic tester. See «CONNECT DIAGNOSTIC TESTER»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb) .
2. Start engine and let run at idle.
3. In diagnostic function "33 - OBD", select "Mode 5: Check output of oxygen sensor signals".
4. Select the desired output of oxygen sensor signals according to the following table. OXYGEN SENSOR SPECIFIED VALUE DIAGNOSIS Test-ID Diagnostic text Specified value min. max. 129: Current value of oxygen sensor signal Bank 1, sensor 1 130: Specified value of oxygen sensor signal Bank 1, sensor 1 131: Dynamic value Bank 1, sensor 1 132: Shift of oxygen sensor regulation before catalytic converter via oxygen sensor regulation behind catalytic converter Bank 1, sensor 1
5. Check values of output for oxygen sensor signals.

If specified values are not obtained

1. Road test vehicle in order to free oxygen sensor of possible residue and repeat test.

If specified values are not obtained again

1. Check primary voltage. See «CHECKING PRIMARY VOLTAGE»(/audi/a4/b7-2004-2009/remont/fuel-system/#multiport-fuel-injection-mfi-generic-scan-tool-18l-5v-turbo-amb) .
2. Test oxygen sensor heater before catalytic converter. See «OXYGEN SENSOR (O2S) HEATER -Z19- BEFORE CATALYTIC CONVERTER, CHECKING»(/audi/a4/b7-2004-2009/remont/fuel-system/#multiport-fuel-injection-mfi-generic-scan-tool-18l-5v-turbo-amb) .
3. Check intake system for leaks (false air). See «INTAKE SYSTEM, CHECKING FOR LEAKS (FALSE AIR)»(/audi/a4/b7-2004-2009/remont/fuel-system/#multiport-fuel-injection-mfi-generic-scan-tool-18l-5v-turbo-amb__intake-system-checking-for-leaks-false) .
4. Check Oxygen Sensor (O2S) and oxygen sensor control behind Three Way Catalytic Converter (TWC). See «OXYGEN SENSORS AND OXYGEN SENSOR REGULATION BEHIND CATALYTIC CONVERTER, CHECKING»(/audi/a4/b7-2004-2009/remont/fuel-system/#multiport-fuel-injection-mfi-generic-scan-tool-18l-5v-turbo-amb__oxygen-sensors-and-oxygen-sensor-regulation) .
5. Checking system pressure and residual pressure. See «SYSTEM PRESSURE AND RESIDUAL PRESSURE, CHECKING»(/audi/a4/b7-2004-2009/remont/fuel-system/#multiport-fuel-injection-mfi-generic-scan-tool-18l-5v-turbo-amb__system-pressure-and-residual-pressure-checking) .
6. Check fuel injectors. See «FUEL INJECTORS, CHECKING»(/audi/a4/b7-2004-2009/remont/fuel-system/#multiport-fuel-injection-mfi-generic-scan-tool-18l-5v-turbo-amb) .
7. Check Evaporative Emission (EVAP) Canister Purge Regulator Valve -N80-. See «CHECKING EVAPORATIVE EMISSION (EVAP) CANISTER PURGE REGULATOR VALVE -N80»(/audi/a4/b7-2004-2009/remont/fuel-system/#fuel-supply-generic-scan-tool-18l-5v-turbo-amb) .
8. Check Fuel Pump (FP). See «FUEL PUMP (FP), ELECTRICAL TESTING»(/audi/a4/b7-2004-2009/remont/fuel-system/#fuel-supply-generic-scan-tool-18l-5v-turbo-amb) for vehicles up to 06.2003, or «FUEL PUMP (FP), ELECTRICAL TESTING»(/audi/a4/b7-2004-2009/remont/fuel-system/#fuel-supply-generic-scan-tool-18l-5v-turbo-amb) for vehicles as of 07.2003.
9. Check exhaust system for proper seal. See «EXHAUST SYSTEM, CHECKING FOR LEAKS»(ref-213311-S16734507392005122900000) .
10. Check Secondary Air Injection (AIR) system for proper seal. See «SECONDARY AIR INJECTION (AIR) SYSTEM, CHECKING FOR PROPER SEAL»(ref-213311-S20933413852005122900000) .
11. Check vacuum lines for proper seal.

Scheme 157

1. Disconnect 6-pin harness connector (black) -5- to Heated Oxygen Sensor (HO2S) -G39- before catalytic converter. NOTE: Coolant reservoir screw (arrow) must be removed and coolant reservoir must be placed to the side in order to access harness connector. The coolant hoses remain connected.
2. Connect multimeter between terminal 1 and 5 for voltage measurement.
3. Switch ignition on. Specified value: 0,400 ... 0.500 V
4. Switch ignition off.

If specified value is not obtained

1. Test oxygen sensor wires. See «CHECK OXYGEN SENSOR WIRES FOR HEATED OXYGEN SENSOR (HO2S) -G39- (BANK 1, SENSOR 1)»(/audi/a4/b7-2004-2009/remont/fuel-system/#multiport-fuel-injection-mfi-generic-scan-tool-18l-5v-turbo-amb) .

If specified value is obtained

1. Replace Heated Oxygen Sensor (HO2S) -G39- before catalytic converter. See «OXYGEN SENSORS, REMOVING AND INSTALLING»(ref-213311-S02249091782005122900000) .

Scheme 158

1. Connect test box to wiring harness of Engine Control Module (ECM). See «TEST BOX, CONNECTING FOR WIRING AND COMPONENT TEST»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb) ; ECM is not connected.
2. Check the following wire connections for open circuit according to wiring diagram: OXYGEN SENSOR TERMINALS & SOCKETS (-G39- BEFORE CATALYTIC CONVERTER) Harness connector Terminal Test box Socket 1 70 2 71 5 51 6 52 Specified value: Wire resistance max 1.5 ohms
3. Also check wires for short circuit to each other as well as to B+ and Ground (GND). Specified value: INFINITY ohms (no continuity)
4. If necessary, repair wire connection.
5. Replace Engine Control Module (ECM).

After repair work, the following work steps must be performed in the mentioned sequence

1. Check DTC memory. See «MODE 3: CHECK DTC MEMORY»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb__mode-3-check-dtc-memory) .
2. If necessary, erase DTC memory. See «MODE 4: RESET/ERASE DIAGNOSTIC DATA»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb__mode-4-reseterase-diagnostic-data) .
3. Generate readiness code. See «READINESS CODE, GENERATING»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb) .

1. End diagnosis and switch ignition off.

Oxygen sensors and oxygen sensor regulation behind catalytic converter, checking

Note. The oxygen sensor before catalytic converter (bank 1, sensor 1) regulates to Lambda 1. If this oxygen sensor is damaged, e.g. due to soiling or overheating, the regulation value may have shifted. Deviations from Lambda 1 are detected by the oxygen sensor behind catalytic converter (bank 1, sensor 2). If it recognizes the deviations downward or upward, it influences the regulation before catalytic converter, generally increasing or decreasing it respectively.

1. VAG1526A hand multimeter
2. VAG1594A connector test kit
3. VAG1598/31 test box

1. Fuses for engine electronics OK See appropriate System Wiring Diagram article.
2. Ground (GND) connections at engine and transmission OK
3. Oxygen sensor heater OK; check. See «OXYGEN SENSOR (O2S) HEATER -Z19- BEFORE CATALYTIC CONVERTER, CHECKING»(/audi/a4/b7-2004-2009/remont/fuel-system/#multiport-fuel-injection-mfi-generic-scan-tool-18l-5v-turbo-amb) .
4. Exhaust system free of leaks.
5. Parking brake engaged.
6. Vehicles with automatic transmission: Selector lever in position "P" or "N".
7. Electrical consumers switched off (radiator fan must NOT run during test).
8. A/C switched off.
9. Coolant temperature at least 80 °C; "PID 05: Coolant temperature". See «MODE 1: CHECK MEASURED VALUES»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb__mode-1-check-measured-values) .

Scheme 159

1. Connect diagnostic tester. See «CONNECT DIAGNOSTIC TESTER»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb) .
2. Start engine and let run at idle.
3. In diagnostic function "33 - OBD", select "Mode 5: Check output of oxygen sensor signals". NOTE: When selecting the diagnostic mode, the entry is always performed in "Bank 1 sensor 1". If either the V.A.G 1551/1552 Scan Tool (ST) or the VAS5051/5052 Vehicle Diagnostic, Testing and Information System is used for checking the output of oxygen sensor signals, the respective oxygen sensor can be selected by pressing buttons 1 and 2: - - Button 1 = Bank 1 sensor 1, - - Button 2 = Bank 1 sensor 2.
4. Select the desired output of oxygen sensor signals according to the following table. OXYGEN SENSOR SPECIFIED VALUE DIAGNOSIS - HO2S BEHIND CATALYTIC CONVERTER Test-ID Diagnostic text Specified value min. max. 07: Minimum voltage at sensor for test cycle Bank 1, sensor 2 0.000 V 0.565 V 08: Maximum voltage at sensor for test cycle Bank 1, sensor 2 0.590 V 1.040 V
5. Check values of output for oxygen sensor signals. *) V = Voltage in Volts (oxygen sensor signal) **) t = Time in seconds

If specified values are not obtained

1. Road test vehicle in order to free oxygen sensors of possible residue and repeat test.

If specified values are not obtained again

Scheme 160

1. Disconnect electrical 4-pin harness connector -2- from Oxygen Sensor (O2S) Behind Three Way Catalytic Converter (TWC) -G130- (bank 1, sensor 2). NOTE: Coolant reservoir screw (arrow) must be removed and coolant reservoir must be placed to the side in order to access harness connector. The coolant hoses remain connected.
2. Connect multimeter between terminal 3 and 4 for voltage measurement.
3. Switch ignition on. Specified value: 0,400 ... 0.500 V
4. Switch ignition off.

If specified value is not obtained

1. Test oxygen sensor wires. See «Check oxygen sensor wires for Oxygen Sensor (O2S) Behind Three Way Catalytic Converter (TWC) -G130- (bank 1, sensor 2)»(/audi/a4/b7-2004-2009/remont/fuel-system/#multiport-fuel-injection-mfi-generic-scan-tool-18l-5v-turbo-amb) .

If specified value is obtained

1. Replace oxygen sensor behind catalytic converter. See «OXYGEN SENSORS, REMOVING AND INSTALLING»(ref-213311-S02249091782005122900000) .

Scheme 161

1. Connect test box to wiring harness of Engine Control Module (ECM). See «TEST BOX, CONNECTING FOR WIRING AND COMPONENT TEST»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb) .
2. Check the following wire connections for open circuit according to wiring diagram: OXYGEN SENSOR TERMINALS & SOCKETS - OXYGEN SENSOR BEHIND THREE WAY CATALYTIC CONVERTER -G130- Harness connector Terminal Test box Socket 3 68 4 69 Specified value: Wire resistance max 1.5 ohms
3. Also check wires for short circuit to each other as well as to B+ and Ground (GND). Specified value: INFINITY ohms (no continuity)
4. If necessary, repair wire connection.
5. Replace Engine Control Module (ECM).

After repair work, the following work steps must be performed in the mentioned sequence

1. Check DTC memory. See «MODE 3: CHECK DTC MEMORY»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb__mode-3-check-dtc-memory) .
2. If necessary, erase DTC memory. See «MODE 4: RESET/ERASE DIAGNOSTIC DATA»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb__mode-4-reseterase-diagnostic-data) .
3. Generate readiness code. See «READINESS CODE, GENERATING»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb) .

1. VAG1526A hand multimeter
2. VAG1594A connector test kit
3. VAG1598/31 test box

1. Fuses for engine electronics OK See appropriate System Wiring Diagram article.
2. Ground (GND) connections at engine and transmission OK
3. Battery voltage at least 12.5 V
4. Generator OK
5. Ignition switched off.

1. Connect test box to wiring harness of Engine Control Module (ECM). See «TEST BOX, CONNECTING FOR WIRING AND COMPONENT TEST»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb) ; ECM is not connected.
2. Switch ignition on. NOTE: The plus voltage supply for the Engine Control Module (ECM) travels via terminal 3 (terminal 15) and terminal 62 (terminal 30). Ground (GND) supply of the Engine Control Module (ECM) travels via terminal 1 and terminal 2.
3. Connect multimeter for voltage measurement as follows: ECM VOTAGE & GROUND CIRCUIT TEST: TEST BOX SOCKETS 1, 2, 62 Test box Socket Measure to 1 B+ 2 B+ 62 Engine Ground (GND) Specified value: approx. battery voltage
4. Switch ignition off.
5. Connect multimeter for voltage measurement as follows: ECM VOTAGE & GROUND CIRCUIT TEST: TEST BOX SOCKET 3 Test box Socket Measure to 3 Engine Ground (GND)
6. Switch ignition on. Specified value: approx. battery voltage
7. Switch ignition off.

If specified values are not obtained

1. Check wire connections for open circuit according to wiring diagram. Specified value: Wire resistance max 1.5 ohms
2. Connect multimeter for voltage measurement as follows: ECM VOTAGE & GROUND CIRCUIT TEST: TEST BOX SOCKET 121 Test box Socket Measure to 121 (1) Engine Ground (GND) (1) Motronic Engine Control Module (ECM) Power Supply Relay -J271- continues to direct current to terminal 121 of the Engine Control Module (ECM) for up to 15 minutes after ignition is switched off
3. Switch ignition on. Specified value: approx. battery voltage
4. Switch ignition off.

If specified value is not obtained

1. Check wire connections for open circuit according to wiring diagram. Specified value: Wire resistance max 1.5 ohms If necessary, repair wire connection. Check Motronic Engine Control Module (ECM) voltage supply relay -J271-. See «CHECK MOTRONIC ENGINE CONTROL MODULE (ECM) POWER SUPPLY RELAY -J271- AND ACTIVATION»(/audi/a4/b7-2004-2009/remont/fuel-system/#multiport-fuel-injection-mfi-generic-scan-tool-18l-5v-turbo-amb__check-motronic-engine-control-module-ecm) .

After repair work, the following work steps must be performed in the mentioned sequence

1. Check DTC memory. See «MODE 3: CHECK DTC MEMORY»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb__mode-3-check-dtc-memory) .
2. If necessary, erase DTC memory. See «MODE 4: RESET/ERASE DIAGNOSTIC DATA»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb__mode-4-reseterase-diagnostic-data) .
3. Generate readiness code. See «READINESS CODE, GENERATING»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb) .

Check Motronic Engine Control Module (ECM) Power Supply Relay -J271- and activation

Special Tools and Equipment

1. VAG1526A hand multimeter
2. VAG1594A connector test kit
3. VAG1598/31 test box

Note. The Motronic Engine Control Module (ECM) voltage supply relay -J271- supplies voltage to the ignition coils with power output stages and the Engine Control Module (ECM) at pin 121.

1. Ignition switched off.

Scheme 162

1. Remove engine cover (arrows).
2. Disconnect the 4-pin harness connector -1- at one ignition coil -2-. NOTE: For further testing, connect the multimeter to harness connector in place of an ignition coil.
3. Connect multimeter for voltage measurement as follows. ECM POWER SUPPLY RELAY: TERMINAL 1 Harness connector Terminal Measure to 1 Engine Ground (GND)
4. Switch ignition on. Specified value: approx. battery voltage
5. Switch ignition off.

If specified value is not obtained

Scheme 163

1. Remove rubber seal for plenum chamber cover.
2. Remove plenum chamber cover -1- toward front (arrows).
3. Pry off both covers -3- using a screwdriver.
4. Loosen hex-nuts -4- by several turns.
5. Loosen wiper arm -2- from wiper axle by lightly tilting.
6. Remove hex nuts completely and remove wiper arms.
7. Disconnect securing clips -1- and remove cowl grill -5-.
8. Remove cover for E-box, plenum chamber (arrows).
9. Pry off Engine Control Module (ECM) retaining bracket (arrows) using a screwdriver and set control module aside.
10. If installed, unclip Transmission Control Module (TCM) retaining bracket and set control module aside.
11. Disconnect voltage supply relay -3-.
12. Check the following wire connection for open circuit according to wiring diagram: ECM POWER SUPPLY RELAY: TERMINAL 8 Relay carrier in E-box, plenum chamber, position 3 Terminal Harness connector at ignition coils Terminal 8 1 Specified value: Wire resistance max 1.5 ohms
13. If necessary, repair wire connection.

If no malfunctions are found in wires

1. Check voltage supply of Motronic Engine Control Module (ECM) voltage supply relay -J271-. See «CHECKING VOLTAGE SUPPLY»(/audi/a4/b7-2004-2009/remont/fuel-system/#multiport-fuel-injection-mfi-generic-scan-tool-18l-5v-turbo-amb) .
2. Check activation of Motronic Engine Control Module (ECM) voltage supply relay -J271-. See «CHECKING ACTIVATION»(/audi/a4/b7-2004-2009/remont/fuel-system/#multiport-fuel-injection-mfi-generic-scan-tool-18l-5v-turbo-amb) .

Scheme 164

1. Connect multimeter for voltage measurement as follows. ECM POWER SUPPLY RELAY: TERMINALS 1 & 2 Relay carrier in E-box, plenum chamber, position 3 Terminal Measure to 1 Engine Ground (GND) 2 Engine Ground (GND) Specified value: approx. battery voltage

If specified value is not obtained

1. Check wire connections for open circuit according to wiring diagram. Specified value: Wire resistance max 1.5 ohms

Scheme 165

1. Connect multimeter for voltage measurement as follows. ECM POWER SUPPLY RELAY: TERMINAL 4 VOLTAGE Relay carrier in E-box, plenum chamber, position 3 Terminal Measure to 4 B+
2. Switch ignition on. Specified value: approx. battery voltage
3. Switch ignition off.

If specified value is not obtained

Scheme 166

1. Connect test box to wiring harness of Engine Control Module (ECM). See «TEST BOX, CONNECTING FOR WIRING AND COMPONENT TEST»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb) ; ECM is not connected.
2. Check the following wire connection for open circuit according to wiring diagram: ECM POWER SUPPLY RELAY: TERMINAL 4 & SOCKET 23 Relay carrier in E-box, plenum chamber, position 3 Terminal Test box Socket 4 23 Specified value: Wire resistance max 1.5 ohms
3. Also check the wire for short circuit to B+ and Ground (GND). Specified value: INFINITY ohms (no continuity)
4. If necessary, repair wire connection.

If no malfunctions are detected

1. Replace Motronic Engine Control Module (ECM) voltage supply relay -J271-.

Removing

1. Pull off rubber seal of plenum chamber cover in direction of arrow.
2. Remove cover -1- toward front.
3. Pry off both covers -3- using a screwdriver.
4. Loosen hex-nuts -4- by several turns.
5. Loosen wiper arm -2- from wiper axle by lightly tilting.
6. Remove hex nuts completely and remove wiper arms.
7. Disconnect securing clips -1- and remove cowl grill -5-.
8. Remove cover for E-box, plenum chamber (arrows).
9. Using a screwdriver, pry off retaining bracket (arrows).
10. Disengage connector catches (arrows) and disconnect harness connectors -1- and -2- from Engine Control Module (ECM). NOTE: Adaptation values are erased when connector is disconnected from the Engine Control Module (ECM), DTC memory content remains intact.
11. Remove Engine Control Module (ECM).

Installation is performed in the reverse order of removal.

After connecting harness connectors to Engine Control Module (ECM), the following work steps must be performed in the mentioned sequence

1. Check DTC memory. See «MODE 3: CHECK DTC MEMORY»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb__mode-3-check-dtc-memory) .
2. If necessary, erase DTC memory. See «MODE 4: RESET/ERASE DIAGNOSTIC DATA»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb__mode-4-reseterase-diagnostic-data) .
3. If DTC memory was erased, generate readiness code. See «READINESS CODE, GENERATING»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb) .

Replacing Engine Control Module (ECM)

Note. To achieve optimal anti-theft protection for the vehicle, an anti-theft immobilizer was installed. The anti-theft immobilizer is a system for enabling/locking the Engine Control Module (ECM). So that this system cannot be circumvented, it is necessary to perform adaptation of the anti-theft immobilizer using the VAS 5052 in the On Board Diagnostic (OBD) function. The great availability of equipment options makes adaptation of the Engine Control Module (ECM) necessary (e.g. cruise control system). This "writing" function is not possible with the generic scan tool, therefore it is necessary to use the VAS 5052 in On Board Diagnostic (OBD) function for this purpose. Procedure to replace Engine Control Module (ECM): See ENGINE CONTROL MODULE (ECM) (WITHOUT METAL ANTI-THEFT HOUSING), REPLACING or ENGINE CONTROL MODULE (ECM) (WITH METAL ANTI-THEFT HOUSING), REPLACING .

After connecting harness connectors to Engine Control Module (ECM), the following work steps must be performed in the mentioned sequence

1. Check DTC memory. See «MODE 3: CHECK DTC MEMORY»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb__mode-3-check-dtc-memory) .
2. If necessary, erase DTC memory. See «MODE 4: RESET/ERASE DIAGNOSTIC DATA»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb__mode-4-reseterase-diagnostic-data) .
3. If DTC memory was erased, generate readiness code. See «READINESS CODE, GENERATING»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb) .

1. Function and display of speedometer OK. Troubleshooting: CAUTION: To reduce the risk of accident during road tests, always observe safety precautions. See «Safety precautions»(/audi/a4/b7-2004-2009/remont/fuel-system/#multiport-fuel-injection-mfi-generic-scan-tool-18l-5v-turbo-amb__safety-precautions) .

Checking

1. Connect diagnostic tester. See «CONNECT DIAGNOSTIC TESTER»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb) .
2. Start engine and let run at idle.
3. In diagnostic function "33 - OBD", select "Diagnostic mode 1 - Check measuring values".
4. Select the desired measuring value "PID 13 - Vehicle speed".
5. Perform a road test, and have a 2nd person observe the indication on the display. PID 13 DIAGNOSTIC CHART PID Diagnostic text Specified value 13 Vehicle speed approx. vehicle speed
6. End diagnosis and switch ignition off.

If no speed is displayed

1. Check terminal resistance for CAN-Bus. See «TERMINAL RESISTANCE FOR CAN-BUS, CHECKING»(/audi/a4/b7-2004-2009/remont/fuel-system/#multiport-fuel-injection-mfi-generic-scan-tool-18l-5v-turbo-amb__terminal-resistance-for-can-bus-checking) .

After repair work, the following work steps must be performed in the mentioned sequence

1. Check DTC memory. See «MODE 3: CHECK DTC MEMORY»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb__mode-3-check-dtc-memory) .
2. Erase DTC memory. See «MODE 4: RESET/ERASE DIAGNOSTIC DATA»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb__mode-4-reseterase-diagnostic-data) .
3. Generate readiness code. See «READINESS CODE, GENERATING»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb) .

Terminal resistance for CAN-Bus, checking

The Engine Control Module (ECM) communicates with all databus-capable control modules via a CAN-Bus.

These databus-capable control modules are connected via two data bus wires which are twisted together (CAN_High and CAN_Low), and exchange information (messages). Missing information on the CAN-Bus is recognized as a malfunction and stored.

Trouble-free operation of the CAN-Bus requires that it have a terminal resistance. This central terminal resistor is located in the Engine Control Module (ECM).

1. VAG1526A hand multimeter
2. VAG1594A connector test kit
3. VAG1598/31 test box

1. Ignition switched off.

1. Connect test box to the Engine Control Module (ECM). See «TEST BOX, CONNECTING FOR WIRING AND COMPONENT TEST»(/audi/a4/b7-2004-2009/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb) ; wiring harness is not connected.
2. Check the central termination resistor in the Engine Control Module (ECM)
3. Connect multimeter between terminal 58 and 60 of test box for resistance measurement. Specified value: 60 ... 72 ohms

If the specification is exceeded or not met

1. Replace Engine Control Module (ECM).

If specified value is obtained

1. Disconnect test box from Engine Control Module (ECM).
2. Connect test box to control module wiring harness.
3. Check CAN data bus wires for short circuit to each other
4. Connect multimeter between terminal 58 and 60 of test box for resistance measurement. Specified value: INFINITY ohms (no continuity)
5. If necessary, repair wire connection according to wiring diagram.

See also:
• READINESS CODE, GENERATING
• CHECKING EVAPORATIVE EMISSION (EVAP) CANISTER PURGE REGULATOR VALVE -N80
• MALFUNCTION INDICATOR LAMP (MIL) -K83- IN INSTRUMENT CLUSTER
• ELECTRONIC POWER CONTROL (EPC) WARNING LAMP -K132- IN INSTRUMENT CLUSTER
• ACCELERATOR LINKAGE, SERVICING
• CAMSHAFT POSITION (CMP) SENSOR -G40-, CHECKING
• IGNITION COILS WITH POWER OUTPUT STAGES, CHECKING
• MODE 3: CHECK DTC MEMORY
• MODE 4: RESET/ERASE DIAGNOSTIC DATA
• MODE 1: CHECK MEASURED VALUES
• FUEL PUMP, REMOVING AND INSTALLING
• ENGINE CONTROL MODULE (ECM) (WITHOUT METAL ANTI-THEFT HOUSING), REPLACING
• ENGINE CONTROL MODULE (ECM) (WITH METAL ANTI-THEFT HOUSING), REPLACING
• Heated Oxygen Sensor (HO2S) -G39- and oxygen sensor regulation before catalytic converter, checking
• OXYGEN SENSORS AND OXYGEN SENSOR REGULATION BEHIND CATALYTIC CONVERTER, CHECKING
• ENGINE SPEED (RPM) SENSOR -G28-, CHECKING
• Component location of Secondary Air Injection (AIR) Solenoid Valve -N112- and Recirculating valve for turbocharger -N249
• Component location of harness connectors
• COMPONENT LOCATION, THROTTLE POSITION (TP) SENSOR -G79- AND SENDER 2 FOR ACCELERATOR PEDAL POSITION -G185
• COMPONENT LOCATION OF BRAKE LIGHT SWITCH -F- AND BRAKE PEDAL SWITCH -F47-, CLUTCH VACUUM VENT VALVE SWITCH -F36
• CLUTCH VACUUM VENT VALVE SWITCH -F36-, CHECKING
• COMPONENT LOCATIONS IN E-BOX, PLENUM CHAMBER
• CHECK MOTRONIC ENGINE CONTROL MODULE (ECM) POWER SUPPLY RELAY -J271- AND ACTIVATION
• COMPONENT LOCATION OF FUEL PUMP (FP) RELAY -J17
• FUEL PUMP (FP) RELAY -J17- AND ACTIVATION, CHECKING
• COMPONENT LOCATION OF CHARGE AIR PRESSURE SENSOR -G31
• THROTTLE VALVE CONTROL MODULE -J338-, CHECKING
• INTAKE AIR TEMPERATURE (IAT) SENSOR -G42-, CHECKING
• FUEL INJECTORS, REMOVING AND INSTALLING
• OVERVIEW OF COMPONENT LOCATIONS
• INTAKE SYSTEM, CHECKING FOR LEAKS (FALSE AIR)
• CHECKING WIRE CONNECTIONS
• CHECK VOLTAGE SUPPLY FOR FUEL PUMP (FP) AND COMPONENTS
• CHECKING FUEL PRESSURE REGULATOR - VEHICLES WITH ALL WHEEL DRIVE (AWD)
• SYSTEM PRESSURE AND RESIDUAL PRESSURE, CHECKING
• INSTALLING
• Safety precautions
• TERMINAL RESISTANCE FOR CAN-BUS, CHECKING