Fuel Supply, Generic Scan Tool (4.2l v8 5v - Art, Awn, Bbd) Audi S6 C5

General Repair Notes

Observe safety precautions. See SAFETY PRECAUTIONS WHEN WORKING ON FUEL SUPPLY SYSTEM .

Observe rules for cleanliness. See RULES OF CLEANLINESS .

Safety precautions when working on fuel supply system

The following steps should be taken before beginning work on the fuel supply system

1. Disconnect battery Ground (GND) strap with the ignition switched off.
2. Open fuel tank cap briefly and close again.

When removing and installing components from full or partially filled fuel tanks, the following must be observed

1. Before starting work, switch on exhaust extraction system and place an extraction hose close to the sensor opening in fuel tank to extract escaping fuel fumes. If no exhaust extraction system is available, a radial fan (as long as motor is not in air flow) with a displacement greater than 15 m 3 /h can be used.
2. Prevent fuel from contacting skin! Wear fuel-resistant gloves!

Rules of cleanliness

When working on the fuel supply/injection system, pay careful attention to the following rules of cleanliness

1. Thoroughly clean all connection areas and the surrounding area before disconnecting.
2. Place parts that have been removed on a clean surface and cover. Use lint-free cloths only!
3. Carefully cover 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: Do not work with compressed air. Do not move vehicle unless absolutely necessary.

Fuel supply system

Note. Secure all hose connections using hose clamps appropriate for the model type: See parts catalog. VAG1921 hose clip pliers are recommended for installing spring-type clamps. Always replace seals and gaskets.

Part I

Note. The following list refers to (Scheme 520).

1. Bolt M8 x 28 with permanent washer Tighten to 23 Nm
2. Mounting clip For heat shield Check for secure fitting
3. Carrier plate
4. Vent line Front end to Evaporative Emission (EVAP) Canister Purge Regulator Valve -N80- clipped in at top of fuel tank Remains on fuel tank when fuel tank is removed
5. Fuel return line From engine Mark before removing Note direction of arrow on connector flange Clipped in on fuel tank, at front right
6. Fuel supply line from fuel filter To fuel rail Mark before removing
7. 2 Nm
8. Heat shield for fuel filler tube
9. Bolt M8 x 28 with permanent washer Tighten to 23 Nm
10. Spring nut - 1.3 Nm
11. Overflow hose
12. Rubber pan
13. Tensioning ring
14. Seal Replace if damaged
15. Cap Attached to tank flap with fastening device
16. Ground (GND) connection For discharging electrostatic charge Installed position / check requirements. See «Installation position of Ground (GND) connection»(/audi/s6/c5-1999-2004/remont/fuel-system/#fuel-supply-generic-scan-tool-42l-v8-5v-art-awn-bbd__installation-position-of-ground-gnd-connection) . Ensure secure seating of connector and secure wire with front securing bolt for fuel filler tube. See item 9 . After installing, check electrical connection of metal ring at fuel filler tube to a blank portion of chassis using Ohm meter. Specified value: approx. 0 ohm
17. Fuel filler tube with reservoir
18. Vent line Rear end to EVAP canister clipped in at top of fuel tank Remains on fuel tank when fuel tank is removed
19. Vent line From fuel filler tube to EVAP canister
20. Heat shield for fuel tank
21. 2 Nm
22. Fuel tank
23. Heat shield for fuel tank
24. Tension strap Note installed position

Part II

Note. The following list refers to (Scheme 521).

1. Heat shield for fuel filler tube
2. Vent line to EVAP canister
3. Hose connection for fuel filling line
4. Vent line To fuel tank at top and front right
5. Vent line From fuel tank at front left
6. Vent line From fuel tank at rear left
7. Vent line From fuel tank at rear right
8. Ground (GND) connection For discharging electrostatic charge Installed position / check requirements. See «INSTALLATION POSITION OF GROUND (GND) CONNECTION»(/audi/s6/c5-1999-2004/remont/fuel-system/#fuel-supply-generic-scan-tool-42l-v8-5v-art-awn-bbd__installation-position-of-ground-gnd-connection) . Ensure secure seating of connector and secure wire with front securing bolt for fuel filler tube. See item 9 . After installing, check electrical connection of metal ring at fuel filler tube to a blank portion of chassis using Ohm meter. Specified value: approx. 0 ohm
9. Rubber pan
10. Tensioning ring
11. Sealing element for fuel nozzle Replace if damaged
12. Seal Replace if damaged
13. Cap Attached to tank flap with fastening device
14. Spring nut - 1.3 Nm
15. Fuel filler tube with reservoir with valves and hoses can only be replaced as complete unit
16. Bolt M8 x 28 with permanent washer Tighten to 23 Nm
17. Bolt M8 x 28 with permanent washer Tighten to 23 Nm
18. Plastic nut - 2 Nm

Installation position of Ground (GND) connection

Note. Check the installation position with fuel filler tube removed.

1. Remove reservoir -1- (arrows) if necessary.
2. Route Ground (GND) connection (arrow) as shown in figure.
3. Ensure connector of Ground (GND) connection fits securely at metal ring of fuel filler tube.
4. Check whether contact is locked at edge of securing hole.
5. Bolt wire contact -1- with securing bolt -2- for fuel filler tube. CAUTION: After installing, check electrical connection of metal ring at fuel filler tube to a blank portion of chassis using Ohm meter: Specified value: approx. 0 Ohm.

Fuel Pump (FP) and Sender for fuel gauge - component overview

Note. The following list refers to (Scheme 525).

1. Union piece Clipped in on baffle housing -Item 2- with retaining clips To remove, press toward left so that retaining clips disengage and lift upward Insert fuel line into baffle housing when installing To remove the Fuel Pump (FP), union piece must be unclipped so that fuel return line (from connector flange) can be disconnected Different versions, allocation. See parts catalog.
2. Baffle housing lower part With suction jet pump
3. Electrical wire To Fuel Level Sensor 2 -G169-, located on left side of fuel tank Connect on connector flange
4. Electrical wire To Sender for fuel gauge -G- Connect on connector flange
5. Harness connector for Fuel Pump (FP) and all senders for fuel gauge Disengaging. See «RELEASING HARNESS CONNECTOR»(/audi/s6/c5-1999-2004/remont/fuel-system/#fuel-supply-generic-scan-tool-42l-v8-5v-art-awn-bbd__releasing-harness-connector) .
6. Return line Clipped in on front at fuel tank Mark before removing
7. Supply line To fuel filter Clipped in on front at fuel tank Mark before removing
8. Locking ring Use ring nut spanner 3087 to remove and install Tighten to 145 Nm
9. Seal replace to install, place into opening of fuel tank dry
10. Connector flange For Fuel Pump (FP) not individually replaceable Installation position: Note arrow marking
11. Fuel pump With Fuel Pump (FP) -G6- Different versions, allocation. Refer to Parts Catalog. Can be replaced only complete with connector flange Check Fuel Pump (FP) electrically. See «FUEL PUMP (FP), ELECTRICAL TESTING»(/audi/s6/c5-1999-2004/remont/fuel-system/#fuel-supply-generic-scan-tool-42l-v8-5v-art-awn-bbd) . Checking fuel delivery. See «DELIVERY QUANTITY OF FUEL PUMP (FP), CHECKING»(/audi/s6/c5-1999-2004/remont/fuel-system/#fuel-supply-generic-scan-tool-42l-v8-5v-art-awn-bbd) . Checking residual pressure. See «FUEL PRESSURE REGULATOR AND RESIDUAL PRESSURE, CHECKING»(/audi/s6/c5-1999-2004/remont/fuel-system/#multiport-fuel-injection-mfi-generic-scan-tool-42l-v8-5v-art-awn-bbd) . Removing and installing. See «FUEL PUMP, REMOVING AND INSTALLING»(/audi/s6/c5-1999-2004/remont/fuel-system/#fuel-supply-generic-scan-tool-42l-v8-5v-art-awn-bbd__fuel-pump-removing-and-installing) .
12. O-Rings replace Check installation position
13. Return line To remove the Fuel Pump (FP), unclip union piece and disconnect fuel return line at union piece -item 1-, release using T40020 to do so. See «RELEASING HOSE COUPLING OF RETURN LINE USING RELEASE TOOL T40020»(/audi/s6/c5-1999-2004/remont/fuel-system/#fuel-supply-generic-scan-tool-42l-v8-5v-art-awn-bbd) .
14. Fuel screen not individually replaceable Clean if soiled

Releasing harness connector

1. To disconnect the multi-pin harness connector at Fuel Pump (FP), the harness connector must be released. This can be done by hand or by using a small screwdriver -arrow-.

Scheme 520

Fuel pump, removing and installing

Recommended special tools and equipment

1. Wrench 2012A
2. 3087 wrench for tank sensor
3. Fuel Pump Wrench 3307
4. VAS5190 fuel siphoning device
5. Release Tool T40020

Empty fuel tank

Observe safety precautions. See SAFETY PRECAUTIONS WHEN WORKING ON FUEL SUPPLY SYSTEM .

Observe rules for cleanliness. See RULES OF CLEANLINESS .

Scheme 521

1. Note radio code (for vehicles equipped with coded anti-theft radio / radio navigation system), obtain if necessary.
2. Remove cover above the battery (arrows). NOTE: For vehicles without separate battery cover: Remove plenum chamber cover.
3. Disconnect battery Ground (GND) wire (arrow) with the ignition switched off.
4. Pull cone piece -2- from shaft piece -1- of VAS 5190.
5. Using insulating tape, apply a mark -arrow- on hose. Dimension a = 1,205 mm
6. Remove fuel filler cap from fuel filler tube.
7. Screw shaft piece -1- of VAS 5190 fuel siphoning device on to fuel filler tube of fuel tank.
8. Slide suction hose as far into fuel tank until the mark applied earlier -arrow- stands on shaft piece. NOTE: Insert hose only up to marking, so that sender for fuel gauge and suction jet pump are not damaged. NOTE: If using a siphoning device without shaft piece, proceed principally in the same manner. Using insulating tape, apply a mark -arrow- on hose. Distance a = 1,140 mm The suction hose -1- is inserted correctly when the marking applied earlier -arrow- stands opposite the lip of fuel filler tube. If the hose can only be inserted with difficulty, smear it thinly with engine oil. Never use lubricants containing silicon.
9. Empty fuel tank as much as possible via fuel filler tube.
10. Carefully remove siphoning hose.

Sedan

1. Remove luggage compartment lining.

Avant

1. Remove luggage compartment floor.

See CARGO AREA FLOOR TRIM AND SUPPORTS (AVANT), REMOVING AND INSTALLING .

Scheme 522

1. Push forward the left 1/3 backrest of rear seat, if necessary.
2. Remove cover for connector flange (arrows).
3. Carefully release and disconnect electrical harness connector (arrow).
4. Use Wrench 2012 A to remove union nut.
5. Pull fuel level sensor 3 and seal carefully out of fuel tank opening.
6. Using fuel siphoning device VAS 5190, siphon remaining fuel out of left and right fuel tank chambers through the sensor opening.
7. Remove rear seat bench. See «SEAT BENCH, REMOVING AND INSTALLING»(/audi/s6/c5-1999-2004/remont/seats/#seats-frames__seat-bench-removing-and-installing) .
8. Remove cover for right connector flange (arrows).
9. Carefully release and disconnect electrical harness connector (arrow). CAUTION: Fuel system is under pressure! Before opening system, place rags around the connection area. Then release pressure by carefully loosening connection.
10. Mark fuel supply line -1- and fuel return line -2- and disconnect from connector flange (right side of vehicle).
11. Use 3087 wrench to remove locking ring.
12. Pull connector flange and sealing ring from opening of fuel tank.
13. Disconnect both harness connectors -1- and -2- to fuel gauge on inside of connector flange.
14. Unclip union piece -1- at lower part of baffle housing, to do so, carefully press union piece toward left side of vehicle and lift upward (arrow). NOTE: Baffle housing is shown without fuel tank for the sake of illustration.
15. Disconnect fuel return line -2- from union piece...
16. ... to do so, release hose coupling of return line using Release Tool T40020.
17. Insert fuel pump wrench 3307 through fuel tank opening and position on inner part of baffle housing.
18. Rotate inner part of baffle housing with pump toward left approx. 15 ° to stop. Notch -1- aligns with marking -2- (bayonet connection)
19. Remove Fuel Pump (FP) with inner part of baffle housing.

Installing

Installation is the reverse of removal, noting the following

Note. Secure all hose connections using hose clamps appropriate for the model type.

Scheme 523

Scheme 524

Scheme 525

1. Insert inner part of baffle housing into outer part of baffle housing in fuel tank so the notch -1- on inner part of baffle housing aligns with marking -2- on outer part of baffle housing. Inner part of baffle housing can be pressed downward significantly and noticeably.
2. Insert fuel pump wrench 3307 through fuel tank opening and position on inner part of baffle housing.
3. Rotate inner part of baffle housing with pump toward right approx. 15° to stop. Notch -1- aligns with marking -3- (bayonet connection)
4. Insert rigid line -3- and hose line -5- into the corresponding holes of baffle housing -6-. see scheme 35
5. Press on return line -1- on union piece -4- until hose coupling engages. see scheme 35 NOTE: Always use new O-rings -7- for the fuel return line. Coat O-rings for fuel return line with fuel or with lubricant.
6. Clip in rigid line -3- on union piece -4-, while doing this the union piece engages itself into baffle housing -6-. see scheme 35
7. Connect harness connectors -1- and -2- for fuel gauge on inside of connector flange.
8. Insert new, dry seal for connector flange into opening of fuel tank.
9. When connecting the connector flange, ensure clearance of electrical wires -2- to Fuel Pump (FP) and to return hose -1-.
10. When installing, turn connector flange in direction of arrow as shown in illustration.
11. Insert connector flange in fuel tank, note installation position: Marking on connector flange -1- must align with marking on fuel tank -2-. NOTE: Arrow points in direction of travel.
12. Tighten locking ring.
13. Install supply and return hose according to marking.
14. Install cover for connector flange so that the protrusion lies over the harness connector.
15. Insert sensor 3 -item 2- in fuel tank as depicted in illustration. Floater -1- faces front left NOTE: Arrow points in direction of travel. Fuel tank is depicted as cut-out section.
16. When sliding in, turn sensor clockwise around its own axis (arrow). NOTE: Do not bend floater arm of sender for fuel gauge when installing. Sensor 3 is properly inserted when: Floater -1- and arm -2- of sensor face front left NOTE: Arrow points in direction of travel. Fuel tank is depicted as cut-out section.
17. Slide new seal for fuel level sensor 3 over connector flange of sensor.
18. Insert dry seal into opening of fuel tank.
19. Check the installation position of fuel level sensor 3. Marking on sensor -2- must align with marking on fuel tank -1- NOTE: Arrow points in direction of travel.
20. Tighten union nut for fuel level sensor 3. NOTE: Be sure to activate vehicle features (radio/radio-navigation system, clock, electric window regulators) according to owner's manual when the battery is re-connected. Deactivate service mode of Telematics Control Module. See «TELEMATICS, ON BOARD DIAGNOSTIC (OBD)»(/audi/s6/c5-1999-2004/remont/communication-devices/#on-board-diagnostic-obd-radio-navigation-steering-telematics). Generate readiness code. See «READINESS CODE, GENERATING»(/audi/s6/c5-1999-2004/remont/testing-diagnostics/#on-board-diagnostic-obd-generic-scan-tool-42l-v8-5v-art-awn-bbd).

Tightening torques

TIGHTENING TORQUES: LOCKING RING FOR FUEL PUMP

Final procedures

After re-connecting the voltage supply, the following work steps must be performed in the mentioned sequence

1. Check DTC memory. See «MODE 3: CHECK DTC MEMORY»(/audi/s6/c5-1999-2004/remont/testing-diagnostics/#on-board-diagnostic-obd-generic-scan-tool-42l-v8-5v-art-awn-bbd__mode-3-check-dtc-memory) .
2. If necessary, erase DTC memory. See «MODE 4: RESET/ERASE DIAGNOSTIC DATA»(/audi/s6/c5-1999-2004/remont/testing-diagnostics/#on-board-diagnostic-obd-generic-scan-tool-42l-v8-5v-art-awn-bbd__mode-4-reseterase-diagnostic-data) .
3. Generate readiness code. See «READINESS CODE, GENERATING»(/audi/s6/c5-1999-2004/remont/testing-diagnostics/#on-board-diagnostic-obd-generic-scan-tool-42l-v8-5v-art-awn-bbd) .

1. End diagnosis and switch ignition off.

1. 3087 wrench for tank sensor
2. VAG1348/3A remote control with VAG1348/3-2 adapter cable
3. VAG1526A hand multimeter
4. VAG1594A connector test kit

Test requirements

1. Battery voltage at least 12.7 V
2. Fuse S228 OK (position 28)
3. Fuel Pump (FP) Relay OK; checking. See «FUEL PUMP (FP) RELAY -J17- AND ACTIVATION, CHECKING»(/audi/s6/c5-1999-2004/remont/fuel-system/#multiport-fuel-injection-mfi-generic-scan-tool-42l-v8-5v-art-awn-bbd) .
4. Fuel filter OK
5. Ignition switched off.

Test sequence

1. Open cover of fuse box at left side of instrument cluster.
2. Remove fuse S228 at fuse carrier (position 28) (left row, 5th large fuse from top).
3. Connect V.A.G 1348/3A remote control connection using adapter cables from VAG1348/3-2 at right terminal of socket from fuse S228 (arrow).
4. Connect alligator clip to vehicle battery B+.
5. Press switch of remote control. Operating noise of the pump must be audible in vicinity of fuel tank.

Note. Fuel Pump (FP) runs quietly. Surrounding noise should be avoided during test of the Fuel Pump (FP).

If no operating noise can be heard

1. Remove rear seat bench. See «SEAT BENCH, REMOVING AND INSTALLING»(/audi/s6/c5-1999-2004/remont/seats/#seats-frames__seat-bench-removing-and-installing) .
2. Remove cover for right connector flange (arrows).
3. Carefully release and disconnect electrical harness connector (arrow).
4. Connect multimeter between terminal 1 and 4 of harness connector for voltage measurement.
5. Press switch of remote control. Specified value: approx. battery voltage

If specified value is obtained, although no operating noise can be heard from pump

Scheme 526

1. Mark fuel supply line -1- and fuel return line -2- and disconnect from connector flange (right side of vehicle). CAUTION: Connector flange may only be opened when fuel tank is maximum 1/4 full. Otherwise, a large amount of fuel will spill out. Empty fuel tank if necessary. Procedure. See «EMPTY FUEL TANK»(/audi/s6/c5-1999-2004/remont/fuel-system/#fuel-supply-generic-scan-tool-42l-v8-5v-art-awn-bbd__empty-fuel-tank) .
2. Use 3087 wrench to remove locking ring.
3. Pull connector flange and sealing ring from opening of fuel tank.
4. Check whether electrical wires between flange and Fuel Pump (FP) are connected, and test for continuity if necessary.

If no malfunction is detected in wires, Fuel Pump (FP) is faulty - replace fuel pump.

1. Install Fuel Pump (FP). See «INSTALLING»(/audi/s6/c5-1999-2004/remont/fuel-system/#fuel-supply-generic-scan-tool-42l-v8-5v-art-awn-bbd__installing) . Observe notes for connecting battery.

1. VAG1348/3A remote control with VAG1348/3-2 adapter cable
2. Measuring container, fuel-tight

1. Battery voltage at least 12.7 V
2. Fuel tank at least 1/4 filled.
3. Fuel filter OK
4. Ignition switched off.

Scheme 527

Scheme 528

1. Open cover of fuse box at left side of instrument cluster.
2. Remove fuse S228 at fuse carrier (position 28) (left row, 5th large fuse from top).
3. Connect V.A.G 1348/3A remote control connection using adapter cables from VAG1348/3-2 at right terminal of socket from fuse S228 (arrow).
4. Connect alligator clip to vehicle battery B+.
5. Remove fuel filler cap from fuel filler tube.
6. Remove engine cover (arrows). CAUTION: Fuel system is under pressure! Before opening system, place rags around the connection area. Then release pressure by carefully loosening connection.
7. Disconnect fuel return hose from line connection on fuel rail pipe.
8. Connect assisting hose -arrow- on distributor pipe and hold in a measuring container.
9. Operate remote control for 15 seconds (keep button pressed).
10. Compare fuel quantity pumped with specified value. *) Minimum delivery rate cm 3 /15 s **) Voltage at fuel pump with engine off and pump running (approx. 2 volts less than battery voltage).
11. Install fuel return line with a new hose clamp.

EVAP canister/leak detection system - component overview

Note. The following list refers to see scheme 59.

1. Cap nut - 10 Nm
2. Cover For EVAP canister
3. Stud bolt - 15 Nm
4. Sealing piece
5. Vent line to Evaporative Emission (EVAP) Canister Purge Regulator Valve -N80
6. Vent line from gravity valve at fuel tank
7. Vacuum line to Leak Detection Pump (LDP) -V144
8. Cable tie for securing vacuum line to Leak Detection Pump (LDP) bracket
9. Leak Detection Pump (LDP) -V144- Component location: Under wheel housing liner in rear left wheelhouse Checking. See «LEAK DETECTION PUMP (LDP) -V144-, CHECKING»(/audi/s6/c5-1999-2004/remont/fuel-system/#fuel-supply-generic-scan-tool-42l-v8-5v-art-awn-bbd) .
10. Electrical harness connector Black
11. Connection hose Leak Detection Pump (LDP)/EVAP canister Pressure side to remove, press release button at connection on Leak Detection Pump (LDP)
12. 10 Nm
13. Air filter for Leak Detection Pump (LDP) -V144- no maintenance procedure
14. Sealing piece
15. Cable tie for securing connection hose to wheel housing
16. EVAP canister Component location: Bottom of spare wheel well Removing and installing. See «EVAP CANISTER, REMOVING AND INSTALLING»(/audi/s6/c5-1999-2004/remont/fuel-system/#fuel-supply-generic-scan-tool-42l-v8-5v-art-awn-bbd) .

Removing

1. Remove EVAP canister cover at bottom of spare wheel well.
2. Remove hose connections -1 to 3- at vent lines.
3. Remove sealing pieces above ventilation lines.
4. Remove pin bolts (arrows) and remove EVAP canister.

Installation is the reverse of removal, noting the following

Note. Secure all hose connections using hose clamps appropriate for the model type: See parts catalog.

TIGHTENING TORQUES: EVAP CANISTER

Hose plan, EVAP canister system / Leak detection system

Note. The following list refers to see scheme 61.

1. Throttle valve control module -J338
2. Evaporative Emission (EVAP) canister purge regulator valve -N80- Component location: Front right in engine compartment
3. Vent line From EVAP canister to Evaporative Emission (EVAP) Canister Purge Regulator Valve -N80- Installation position: Right side, beneath vehicle floor secured to fuel tank in fuel tank area
4. Vent line to gravity valve on fuel tank
5. EVAP canister Component location: Bottom of spare wheel well
6. Connection hose Leak Detection Pump (LDP)/EVAP canister Pressure side
7. Air filter for Leak Detection Pump (LDP) -V144
8. Leak Detection Pump (LDP) -V144- Component location: Under wheel housing liner in rear left wheelhouse
9. Vacuum line to Leak Detection Pump (LDP) -V144

Function

The evaporative emissions (EVAP) system, diagnostic leak test recognizes leaks in the entire fuel system including the fuel tank, Evaporative Emission (EVAP) canister and Evaporative Emission (EVAP) Canister Purge Regulator Valve -N80-.

On the mechanical side, the leak detection system consists primarily of a vacuum activated diaphragm pump with a reed contact on an activating rod at the pump diaphragm. The pump is supplied with vacuum via the engine intake stroke.

1. When diagnostic leak test is activated, the Leak Detection Pump (LDP) increases pressure in the fuel system to 20 to 30 mbar.
2. Once the specified pressure is reached, the pump membrane remains expanded so that the reed contact at the operating rod remains in the "open" position.
3. If pressure falls (indicating a leak), the diaphragm moves back and the reed contact closes.
4. If reed contact closes within 10 seconds of leak detection time, a further test procedure is performed: If this is the case, the membrane pump will pump 4 additional strokes. The Engine Control Module (ECM) measures the time between these 4 strokes and closure of the reed contact. From that, the control module can recognize a "small leak" (greater than 1 mm in diameter) or a "large leak".

Leak diagnostic is activated automatically shortly following every engine start. If a malfunction is recognized, a DTC entry follows. The Malfunction Indicator Lamp (MIL) in the instrument cluster lights up if the malfunction is recognized for two subsequent starts.

EVAP canister system, checking for proper seal

Note. Secure all hose connections using hose clamps appropriate for the model type: See parts catalog. Always replace seals and gaskets.

1. Connect diagnostic tester. See «CONNECT DIAGNOSTIC TESTER»(/audi/s6/c5-1999-2004/remont/testing-diagnostics/#on-board-diagnostic-obd-generic-scan-tool-42l-v8-5v-art-awn-bbd) .
2. Start engine and let run at idle for at least 15 minutes.
3. In diagnostic function "33 - OBD", select "Mode 8: Tank leak test". See «MODE 8: TANK LEAK TEST»(/audi/s6/c5-1999-2004/remont/testing-diagnostics/#on-board-diagnostic-obd-generic-scan-tool-42l-v8-5v-art-awn-bbd__mode-8-tank-leak-test) .
4. Select the "Test-ID 01: Tank leak test" and check specified value at idle. Specified value: Test OK NOTE: If the accelerator pedal is depressed during the test, the test will be aborted. To repeat the tank leak test, switch ignition off and start engine again and let run at idle. If specified value is obtained
5. End diagnosis and switch ignition off.

If specified value is not obtained

Checking fuel supply and tank ventilation systems for leaks

1. Check whether fuel filler cap was completely closed for test.
2. Check whether seal of fuel filler cap was damaged or crimped. Replace if necessary.
3. Disconnect and seal connection hose of Leak detection pump (LDP) -V144- at EVAP canister. See item 11 .
4. Repeat function test.

If malfunction persists

1. Remove EVAP canister cover at bottom of spare wheel well.
2. Remove sealing pieces above ventilation lines.
3. Check connection pipes and hoses between Leak detection pump (LDP) -V144- and EVAP canister for proper seal. See «EVAP CANISTER/LEAK DETECTION SYSTEM - COMPONENT OVERVIEW»(/audi/s6/c5-1999-2004/remont/fuel-system/#fuel-supply-generic-scan-tool-42l-v8-5v-art-awn-bbd__evap-canisterleak-detection-system-component) .
4. Repeat function test.

If malfunction persists

1. Remove luggage compartment lining.

1. Remove luggage compartment floor. See «CARGO AREA FLOOR TRIM AND SUPPORTS (AVANT), REMOVING AND INSTALLING»(/audi/s6/c5-1999-2004/remont/exteriorinterior-trim/#interior-trim__cargo-area-floor-trim-and-supports) .

All

1. Remove cover in luggage compartment under luggage compartment floor (arrows).
2. Remove rear seat bench. See «SEAT BENCH, REMOVING AND INSTALLING»(/audi/s6/c5-1999-2004/remont/seats/#seats-frames__seat-bench-removing-and-installing) .
3. Remove cover for connector flange on left and right sides (arrows).
4. Check whether seals under connector flanges are OK and whether lock rings and union nut of connector flange are properly tightened on fuel tank. Also check fuel line connections.
5. Visually check all lines and hose connections of fuel supply system and replace leaking lines, e.g.: Line from EVAP canister to Evaporative Emission (EVAP) Canister Purge Regulator Valve (in engine compartment) Lines from EVAP canister to Leak Detection Pump (LDP) Line from fuel tank to Evaporative Emission (EVAP) canister (under cover for EVAP canister) Lines from EVAP system (under rear right wheel housing liner) Fuel lines to engine NOTE: Leaks at lines and components of fuel tank system can sometimes be located using a non-flammable, environmentally sound engine leak detection spray (e.g. G 001 800 A1). Pressure of (max. 70 mbar) can be applied to the fuel system via the test connection (in engine compartment). Leaks can be determined using engine leak detection spray. When doing this, bubbles form at leaking areas.
6. Repeat function test.

If malfunction persists

1. Visually check components of fuel supply system and EVAP system. Fuel tank EVAP canister Leak Detection Pump (LDP) -V144- Evaporative Emission (EVAP) canister purge regulator valve -N80

Note. Also check vacuum hose setup from engine compartment to leak detection pump for proper seal Because of shape or function of these components it is not always possible to find leaks by applying spray. It may be necessary to clamp off the relevant component using 3094 hose clamps and initiate leak detection diagnostic. If leak is no longer detected, the component that was clamped off is faulty. If clamp is placed directly on the diagnostic pump and a leak is still detected, then the diagnostic pump itself is leaking. Observe installation notes for connector flanges. See 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/s6/c5-1999-2004/remont/testing-diagnostics/#on-board-diagnostic-obd-generic-scan-tool-42l-v8-5v-art-awn-bbd__mode-3-check-dtc-memory) .
2. If necessary, erase DTC memory. See «MODE 4: RESET/ERASE DIAGNOSTIC DATA»(/audi/s6/c5-1999-2004/remont/testing-diagnostics/#on-board-diagnostic-obd-generic-scan-tool-42l-v8-5v-art-awn-bbd__mode-4-reseterase-diagnostic-data) .
3. Generate readiness code. See «READINESS CODE, GENERATING»(/audi/s6/c5-1999-2004/remont/testing-diagnostics/#on-board-diagnostic-obd-generic-scan-tool-42l-v8-5v-art-awn-bbd) .

1. End diagnosis and switch ignition off.

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

1. Fuse for Evaporative Emission (EVAP) canister purge regulator valve -N80- OK
2. Fuel Pump (FP) Relay OK; checking. See «FUEL PUMP (FP) RELAY -J17- AND ACTIVATION, CHECKING»(/audi/s6/c5-1999-2004/remont/fuel-system/#multiport-fuel-injection-mfi-generic-scan-tool-42l-v8-5v-art-awn-bbd) .
3. Ignition switched off.

Note. Voltage supply for Evaporative Emission (EVAP) Canister Purge Regulator Valve -N80- occurs via the fuel pump relay.

Work procedure

1. Disconnect electrical harness connector from Evaporative Emission (EVAP) Canister Purge Regulator Valve -N80-.

Checking internal resistance

1. Connect multimeter at valve for resistance measurement. Specified value: 22 to 30 ohms

If specified value is not obtained.

1. Replace Evaporative Emission (EVAP) canister purge regulator valve -N80-.

If specified value is obtained

Checking voltage supply

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: EVAP CANISTER PURGE REGULATOR VALVE CIRCUIT TEST: TERMINAL 1 Harness connector Terminal Measure to 1 Engine Ground (GND)
2. Operate starter briefly. Specified value: approx. battery voltage

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 ohm
2. If necessary, repair wire connection.

If voltage supply is OK

Scheme 529

1. Connect multimeter for voltage measurement as follows: EVAP CANISTER PURGE REGULATOR VALVE CIRCUIT TEST: TERMINAL 2 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 530

1. Connect test box to wiring harness of Engine Control Module (ECM). See «TEST BOX, CONNECTING FOR WIRING AND COMPONENT TEST»(/audi/s6/c5-1999-2004/remont/testing-diagnostics/#on-board-diagnostic-obd-generic-scan-tool-42l-v8-5v-art-awn-bbd) ; ECM is not connected.
2. Check the following wire connection for open circuit according to wiring diagram: EVAP CANISTER PURGE REGULATOR VALVE CIRCUIT TEST: TERMINAL 2 & TEST BOX SOCKET 64 Harness connector Terminal Test box Socket 2 64 Specified value: Wire resistance max 1.5 ohm
3. Also check the wire for short circuit to B+ and Ground (GND). Specified value: infinity ohm (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/s6/c5-1999-2004/remont/testing-diagnostics/#on-board-diagnostic-obd-generic-scan-tool-42l-v8-5v-art-awn-bbd__mode-3-check-dtc-memory) .
2. If necessary, erase DTC memory. See «MODE 4: RESET/ERASE DIAGNOSTIC DATA»(/audi/s6/c5-1999-2004/remont/testing-diagnostics/#on-board-diagnostic-obd-generic-scan-tool-42l-v8-5v-art-awn-bbd__mode-4-reseterase-diagnostic-data) .
3. Generate readiness code. See «READINESS CODE, GENERATING»(/audi/s6/c5-1999-2004/remont/testing-diagnostics/#on-board-diagnostic-obd-generic-scan-tool-42l-v8-5v-art-awn-bbd) .

1. End diagnosis and switch ignition off.

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

1. Fuse for Leak Detection Pump (LDP) -V144- OK
2. Fuel Pump (FP) Relay OK; checking. See «FUEL PUMP (FP) RELAY -J17- AND ACTIVATION, CHECKING»(/audi/s6/c5-1999-2004/remont/fuel-system/#multiport-fuel-injection-mfi-generic-scan-tool-42l-v8-5v-art-awn-bbd) .
3. Ignition switched off.

Note. Voltage is supplied to Leak detection pump (LDP) -V144- via the Fuel Pump (FP) relay.

1. Remove left rear wheel.
2. Remove rear left wheelhouse liner. See «WHEELHOUSING LINER, REAR»(/audi/s6/c5-1999-2004/remont/mirrors/#exterior-equipment__wheelhousing-liner-rear) .
3. Release and disconnect electrical harness connector.

Scheme 531

1. Connect multimeter for resistance measurement as follows. LEAK DETECTION PUMP (LDP) -V144- CIRCUIT RESISTANCE TEST Leak Detection Pump (LDP) -V144- Terminal Specified value 1 + 3 640 to 720 ohm 2 + 3 15 to 17 ohm

If specified values are not obtained

1. Replace Leak Detection Pump (LDP) -V144-. See item 9 .

If specified values are obtained

Scheme 532

1. Connect multimeter for voltage measurement as follows: LEAK DETECTION PUMP (LDP) -V144- CIRCUIT VOLTAGE SUPPLY TEST Harness connector Terminal Measure to 3 Engine Ground (GND)
2. Operate starter briefly. Specified value: approx. battery voltage
3. Switch ignition off.

If specified value is not obtained

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 ohm
2. If necessary, repair wire connection.

If voltage supply is OK

Scheme 533

1. Connect test box to wiring harness of Engine Control Module (ECM). See «TEST BOX, CONNECTING FOR WIRING AND COMPONENT TEST»(/audi/s6/c5-1999-2004/remont/testing-diagnostics/#on-board-diagnostic-obd-generic-scan-tool-42l-v8-5v-art-awn-bbd) ; ECM is not connected.
2. Check the following wire connections for open circuit according to wiring diagram: LEAK DETECTION PUMP (LDP) -V144- CIRCUIT TEST: TERMINAL 1, 2 & TEST BOX SOCKET 80, 25 Harness connector Terminal Test box Socket 1 80 2 25 Specified value: Wire resistance max 1.5 ohm
3. Also check wires for short circuit to each other as well as to B+ and Ground (GND). Specified value: infinity ohm (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/s6/c5-1999-2004/remont/testing-diagnostics/#on-board-diagnostic-obd-generic-scan-tool-42l-v8-5v-art-awn-bbd__mode-3-check-dtc-memory) .
2. If necessary, erase DTC memory. See «MODE 4: RESET/ERASE DIAGNOSTIC DATA»(/audi/s6/c5-1999-2004/remont/testing-diagnostics/#on-board-diagnostic-obd-generic-scan-tool-42l-v8-5v-art-awn-bbd__mode-4-reseterase-diagnostic-data) .
3. Generate readiness code. See «READINESS CODE, GENERATING»(/audi/s6/c5-1999-2004/remont/testing-diagnostics/#on-board-diagnostic-obd-generic-scan-tool-42l-v8-5v-art-awn-bbd) .

1. End diagnosis and switch ignition off.

Function of E-Gas system

For E-Gas, the throttle valve is not operated by a cable from the accelerator pedal. There is no mechanical connection between the accelerator pedal and the throttle valve.

The position of the accelerator pedal is communicated to the Engine Control Module (ECM) via two sensors for accelerator pedal position (variable resistances; stored in one housing) that are connected with the accelerator pedal.

The accelerator pedal position (driver's intention) is a main input unit for the ECM.

Operation of the throttle valve occurs via an electric motor (throttle valve actuator) in the throttle valve control module. This is true across the entire engine speed and engine load spectrum.

The throttle valve is operated by the throttle valve actuator according to the instructions of the ECM.

With ignition switched on and engine off, the ECM activates the throttle valve actuator precisely according to the sensor for accelerator pedal position. This means, if the accelerator pedal is depressed half way, the throttle valve actuator opens the throttle valve to the same degree; i.e. throttle valve would be opened half way.

With engine running (under load), the ECM can open or close the throttle valve independently of the sensor for accelerator pedal position.

This means, for example, that the throttle valve could be fully opened even though the accelerator pedal has only been depressed half way. This has the advantage of preventing torque losses at the throttle valve.

In addition to this, it results in significantly better values relative to emissions and consumption under certain load conditions.

The required engine torque can be achieved by the Engine Control Module (ECM) via the optimal combination of throttle valve diameter and boost pressure.

It would be incorrect to think that "E-Gas" consists of only one or two components. E-Gas is much more of a system containing all components that contribute to recognizing, controlling and monitoring the position of the throttle valve, e.g. sensor for accelerator pedal position, throttle valve control module, EPC warning lamp, Engine Control Module (ECM).

Accelerator linkage, servicing

Note. The following list refers to see scheme 74.

1. Socket head bolt - 9 Nm
2. 6-pin harness connector
3. Accelerator pedal module with Throttle Position (TP) sensor -G79- and sender -2- for accelerator pedal position -G185- Throttle Position (TP) Sensors -G79- and -G185-, checking. See «THROTTLE POSITION (TP) SENSOR, CHECKING»(/audi/s6/c5-1999-2004/remont/fuel-system/#fuel-supply-generic-scan-tool-42l-v8-5v-art-awn-bbd) . Removing and installing. See «ACCELERATOR PEDAL MODULE WITH THROTTLE POSITION (TP) SENSORS, REMOVING AND INSTALLING»(/audi/s6/c5-1999-2004/remont/fuel-system/#fuel-supply-generic-scan-tool-42l-v8-5v-art-awn-bbd) .

1. Remove driver-side storage compartment. See «DRIVER'S STORAGE COMPARTMENT, REMOVING»(/audi/s6/c5-1999-2004/remont/mirrors/#interior-equipment__drivers-storage-compartment-removing) .
2. Disconnect 6-pin harness connector.
3. Remove threaded connections (3x).
4. Remove accelerator pedal module (arrow).

Installation is the reverse of removal, noting the following

1. In a vehicle with automatic transmission, the kickdown function must be adapted when accelerator pedal module is replaced: 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.
2. 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

Tightening torque

TIGHTENING TORQUES: ACCELERATOR PEDAL MODULE

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

Test requirement

Both the Throttle Position (TP) sensor -G79- and the Sender -2- for accelerator pedal position -G185- are located at the accelerator pedal and communicate the driver's intentions to the ECM completely independently of each other. Both sensors are stored in one housing.

1. Fuses for engine electronics OK

1. Remove driver-side storage compartment. See «DRIVER'S STORAGE COMPARTMENT, REMOVING»(/audi/s6/c5-1999-2004/remont/mirrors/#interior-equipment__drivers-storage-compartment-removing) .
2. Disconnect electrical harness connector -2-.

Scheme 534

1. Switch ignition on.
2. Connect multimeter for voltage measurement as follows. ACCELERATOR PEDAL MODULE CIRCUIT TEST: VOLTAGE SUPPLY Harness connector Terminal Specified value 1 + Ground (GND) approx. 5 V 1 + 5 approx. 5 V 2 + Ground (GND) approx. 5 V 2 + 3 approx. 5 V
3. Switch ignition off.

If specified values are not obtained

Scheme 535

1. Connect test box to wiring harness of Engine Control Module (ECM). See «TEST BOX, CONNECTING FOR WIRING AND COMPONENT TEST»(/audi/s6/c5-1999-2004/remont/testing-diagnostics/#on-board-diagnostic-obd-generic-scan-tool-42l-v8-5v-art-awn-bbd) ; ECM is not connected.
2. Check the following wire connections for open circuit according to wiring diagram: ACCELERATOR PEDAL MODULE CIRCUIT TEST: CONTINUITY Harness connector Terminal Test box Socket 1 72 2 73 3 36 4 35 5 33 6 34 Specified value: Wire resistance max 1.5 ohm
3. Also check wires for short circuit to each other, to B+ and Ground (GND). Specified value: infinity ohm (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 accelerator pedal module. See «ACCELERATOR PEDAL MODULE WITH THROTTLE POSITION (TP) SENSORS, REMOVING AND INSTALLING»(/audi/s6/c5-1999-2004/remont/fuel-system/#fuel-supply-generic-scan-tool-42l-v8-5v-art-awn-bbd) .

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/s6/c5-1999-2004/remont/testing-diagnostics/#on-board-diagnostic-obd-generic-scan-tool-42l-v8-5v-art-awn-bbd__mode-3-check-dtc-memory) .
2. If necessary, erase DTC memory. See «MODE 4: RESET/ERASE DIAGNOSTIC DATA»(/audi/s6/c5-1999-2004/remont/testing-diagnostics/#on-board-diagnostic-obd-generic-scan-tool-42l-v8-5v-art-awn-bbd__mode-4-reseterase-diagnostic-data) .
3. Generate readiness code. See «READINESS CODE, GENERATING»(/audi/s6/c5-1999-2004/remont/testing-diagnostics/#on-board-diagnostic-obd-generic-scan-tool-42l-v8-5v-art-awn-bbd) .

1. End diagnosis and switch ignition off.

See also:
• FUEL PRESSURE REGULATOR AND RESIDUAL PRESSURE, CHECKING
• TELEMATICS, ON BOARD DIAGNOSTIC (OBD)
• CARGO AREA FLOOR TRIM AND SUPPORTS (AVANT), REMOVING AND INSTALLING
• SEAT BENCH, REMOVING AND INSTALLING
• READINESS CODE, GENERATING
• MODE 3: CHECK DTC MEMORY
• MODE 4: RESET/ERASE DIAGNOSTIC DATA
• MODE 8: TANK LEAK TEST
• WHEELHOUSING LINER, REAR
• DRIVER'S STORAGE COMPARTMENT, REMOVING
• SAFETY PRECAUTIONS WHEN WORKING ON FUEL SUPPLY SYSTEM
• RULES OF CLEANLINESS
• EMPTY FUEL TANK
• Installation position of Ground (GND) connection
• RELEASING HARNESS CONNECTOR
• FUEL PUMP (FP), ELECTRICAL TESTING
• FUEL PUMP, REMOVING AND INSTALLING
• INSTALLING
• EVAP CANISTER/LEAK DETECTION SYSTEM - COMPONENT OVERVIEW