4.2l v8 5v Generic Scan Tool, Engine Code(s): Bnk Audi A6 С6

Safety precautions

Take the following steps before beginning work on the fuel supply system

1. Disconnect battery Ground (GND) cable with the ignition switched off --> «27 - STARTER, GENERATOR, CRUISE CONTROL»(/audi/a6/6-2004-2008/remont/cruise-control-systems/#electrical-equipment) .
2. Open fuel filler flap briefly and then close again.

When removing and installing components from full or partially full fuel tanks, observe the following

1. The fuel tank must only be partially full. How much fuel can remain in the fuel tank may be read in the respective work description. Empty the fuel tank if necessary.
2. Before starting work, switch on the exhaust extraction system and place an extraction hose close to the installation opening of the 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.
3. Prevent fuel from contacting skin! Wear fuel-resistant gloves!

Observe the following when removing and installing the fuel tank

1. Fuel tank must be empty for weight reasons.

Rules for cleanliness

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

1. Thoroughly clean all connections and surrounding area before disconnecting.
2. Place parts that have been removed on a clean surface and cover them. Do not use fluffy cloths!
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 unpacked (e.g. in tool boxes etc.).

1. When the system is open: Do not work with compressed air. Do not move vehicle unless absolutely necessary.

Scheme 1201

1 - 23 Nm

2 - Mounting

1. For exhaust system

3 - Carrier plate

4 - Fuel line

1. From fuel filter to engine
2. Do not kink
3. To disconnect, press release button on connection piece

5 - Vent line

1. From EVAP canister to Evaporative Emission (EVAP) Canister Purge Regulator Valve -N80
2. Do not kink
3. To disconnect, press release button on connection piece
4. Clipped in on fuel tank

6 - 23 Nm

7 - Overflow hose

1. Hooked onto wheelhousing liner

8 - Rubber pan

9 - Gasket

1. Replace if damaged

10 - Cap

1. Attached to tank flap unit with fastening device

11 - Ground (GND) connection

1. For discharging electrostatic charge
2. Installed location
3. After installing, check electrical connection of metal ring at fuel filler tube to a bare area of chassis using an Ohm meter - Specified value: approx. 0 ohms

12 - Vent line

13 - Vent line

1. To EVAP canister

14 - Fuel tank

15 - Securing strap

16 - Spreader clip

17 - 23 Nm

18 - Heat shield for fuel tank

19 - 2 Nm

Scheme 1202

1. Route Ground (GND) connection (Scheme 1202)
2. First, engage contact - 3 - of Ground (GND) connection into securing opening on fuel tank - 4 - and then press in spacer bushing - 5 -.
3. Ensure connector of Ground (GND) connection - 1 - fits securely at metal ring - 2 - of fuel filler tube.

Scheme 1203

1 - Fuel delivery unit

1. Fuel pump electrical, checking --> «Fuel pump electrical, checking»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__fuel-pump-electrical-checking) .
2. Removing and installing --> «Fuel delivery unit, removing and installing»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__fuel-delivery-unit-removing-and-installing) .
3. Residual pressure, checking --> «Fuel pressure regulator and holding pressure, checking»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__fuel-pressure-regulator-and-holding-pressure) .

2 - Fuel gauge sender -G

1. Removing and installing --> «20 - FUEL SUPPLY»(/audi/a6/6-2004-2008/remont/fuel-system/#fuel-supply-system) .

3 - Threaded ring

4 - Oil seal

1. Replace
2. Install dry

5 - Union nut

1. Use ring nut wrench T40068 for removal and installation.
2. Replace
3. Fasten to 120 Nm

6 - Fuel return line

1. From fuel filter.
2. Do not kink.
3. Mark before removing.
4. To remove from locking flange, press release button on connecting piece.

1. Note direction of arrow (fuel supply or return) on locking flange when installing.
2. Clipped onto fuel tank.

7 - Fuel supply line

1. To fuel filter.
2. Do not kink.
3. Mark before removing.
4. To remove from locking flange, press release button on connecting piece.

1. Note direction of arrow (fuel supply or return) on locking flange when installing.
2. Clipped onto fuel tank.

8 - Electrical harness connector

1. For Transfer Fuel Pump (FP) -G6-.
2. For Fuel Gauge Sender -G- and Fuel Level Sensor 2 -G169-.

9 - Electrical harness connector

1. For Fuel Level Sensor 2 G169.

10 - Fuel delivery line

1. From suction jet pump to fuel delivery unit.
2. Clipped into fuel delivery unit.

11 - Union nut

1. Use ring nut wrench T40068 for removal and installation.
2. Replace
3. Fasten to 120 Nm

12 - Oil seal

1. Replace
2. Install dry

13 - Threaded ring

14 - Suction jet pump

1. Suction jet pump, checking. --> «20 - FUEL SUPPLY»(/audi/a6/6-2004-2008/remont/fuel-system/#fuel-supply-system) .
2. Removing and installing. --> «20 - FUEL SUPPLY»(/audi/a6/6-2004-2008/remont/fuel-system/#fuel-supply-system) .

15 - Fuel level sensor 2 -G169

1. Resistance values, checking --> «20 - FUEL SUPPLY»(/audi/a6/6-2004-2008/remont/fuel-system/#fuel-supply-system) .
2. Removing and installing --> «20 - FUEL SUPPLY»(/audi/a6/6-2004-2008/remont/fuel-system/#fuel-supply-system) .

16 - Suction jet pipe

1. From fuel pump to suction jet pump.
2. To disconnect, press release button on connection piece.

Fuel tank, emptying

A - Emptying a fuel tank more than 1 / 4 filled --> A - Emptying a fuel tank more than 1/4 filled .

B - Emptying a fuel tank less than 1 / 4 filled --> B - Emptying a fuel tank less than 1/4 filled .

Special tools, testers and auxiliary items required

Scheme 1204

1. Fuel siphoning unit VAS 5190

Work sequence

Observe safety precautions.

Observe rules for cleanliness.

1. Switch off ignition.
2. Release fuel tank flap.
3. Fold luggage compartment floor upward.

Scheme 1205

1. Release retaining clips - arrows - with a screwdriver - 2 - and remove cover - 1 -.

Scheme 1206

1. Disconnect Ground (GND) strap at battery Ground (GND) terminal - arrow -.

Scheme 1207

1. Pull cone piece - 2 - from shaft piece - 1 - of fuel extraction unit VAS 5190.

Scheme 1208

1. Using insulating tape, apply a mark - arrow - on hose at length - a - = 1365 mm from end of suction hose.
2. Remove fuel filler cap from fuel filler tube.
3. Screw shaft piece - 1 - of fuel extraction unit VAS 5190 on to fuel filler tube of fuel tank.
4. Slide suction hose as far into fuel tank until mark applied earlier - arrow - stands at shaft piece.

1. Empty fuel tank as much as possible via fuel filler tube.
2. Carefully pull out suction hose.
3. Remove fuel delivery unit.
4. Extract residual fuel in right chamber of fuel tank through opening of fuel filler tube.

1. Push hose into left chamber of fuel tank and extract residual fuel.

Note. If using a siphoning device without shaft piece, proceed principally in the same manner. In this case, apply a mark - arrow - using insulating tape on hose at length - a - = 1300 mm from end of suction hose - 1 -. The suction hose is inserted correctly when the marking applied earlier stands opposite the lip of fuel filler tube. If the hose can only be inserted with difficulty, coat it thinly with engine oil. Never use lubricants containing silicon.

B - Emptying a fuel tank less than 1/4 filled

1. Remove fuel delivery unit.
2. Extract fuel in right chamber of fuel tank through opening of the fuel filler tube.
3. Push hose into left chamber of fuel tank and extract residual fuel.

Fuel delivery unit, removing and installing

Special tools, testers and auxiliary items required

1. Ring nut wrench T40068.

Removing

Observe safety precautions.

Observe rules for cleanliness.

1. To remove fuel delivery unit, the fuel tank may only be filled to a maximum of 1 / 4 capacity. Empty fuel tank if necessary. --> «Fuel tank, emptying»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__fuel-tank-emptying) .

1. If necessary, move front seats completely forward.

1. Switch off ignition.
2. Fold luggage compartment floor upward.

1. Release retaining clips - arrows - with screwdriver - 2 - and remove cover - 1 -.

1. Disconnect Ground (GND) strap at battery Ground (GND) terminal - arrow -.
2. Remove rear seat bench --> «72 - SEAT - FRAMES»(/audi/a6/6-2004-2008/remont/gauges-instrument-panels/#body-interior) .

Scheme 1209

1. Unbolt cover for right locking flange - arrows -.

Scheme 1210

1. Disconnect electrical connector - arrow - at right locking flange.

Scheme 1211

1. Mark fuel supply line - 1 - and fuel return line - 2 -.

Scheme 1212

1. Pull both lines from locking flange by pressing release buttons.

1. Remove union nut using Ring nut spanner T40068.
2. Pull right locking flange of fuel delivery unit out of opening in fuel tank and set aside with lines still connected.

Scheme 1213

1. Through opening in fuel tank, disconnect electrical connector - 2 - for Fuel Level Sensor 2 -G169-.
2. Disconnect suction jet pipe - 1 - to suction jet pump by pressing release button.
3. Disengage fuel delivery line - 3 -.
4. Remove fuel delivery unit.

Note. When removing fuel delivery unit, be sure not to bend floater arm of Fuel Level Sensor G.

Installing

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

Note. Always replace seal and union nut. When inserting fuel delivery unit, be sure not to bend Fuel Level Sensor G. Ensure fuel hoses are seated securely.

1. Insert fuel delivery unit into fuel tank with locking flange set aside.
2. Attach fuel delivery line - 3 -.
3. Push suction jet pipe - 1 - onto suction jet pump until it engages audibly.
4. Connect electrical connector - 2 - for Fuel Level Sensor 2 -G169-.

Make sure fuel hoses are routed correctly

Scheme 1214

1. The fuel supply line - 1 - must be routed between the guide tube - 4 - and the supports - 2 - for fuel return line. Also, it must be routed around the outside of the guide tube - 3 -.

1. Insert guide tubes - 3 - and - 4 - of locking flange into guide holes - arrows - of the fuel delivery unit.

Note. To improve clarity, the fuel delivery unit is shown without the fuel tank.

Scheme 1215

1. Install new locking flange seal dry.
2. Press locking flange down against spring pressure and bring it into installation position.

Scheme 1216

1. Tab - 2 - on locking flange must lie between tabs - 1 - and - 3 - on threaded ring.

Note. To install, position union nut so that the double ridge - 1 - of the ribs aligns with the tab - 2 - of the locking flange. This will make it easier for union nut to engage the beginning of the thread - 3 -.

1. Tighten union nut for right locking flange.

1. Install fuel supply line - 1 - and fuel return line - 2 - according to marking.
2. Connect electrical connector.
3. Install rear seat bench --> «72 - SEAT - FRAMES»(/audi/a6/6-2004-2008/remont/gauges-instrument-panels/#body-interior) .
4. Connect battery. Observe safety precautions after connecting battery --> «27 - STARTER, GENERATOR, CRUISE CONTROL»(/audi/a6/6-2004-2008/remont/cruise-control-systems/#electrical-equipment) .

Tightening torque

Fuel pump electrical, checking

Special tools, testers and auxiliary items required

1. Remote control V.A.G 1348/3 A with adapter cable V.A.G 1348/3-2
2. Multimeter V.A.G 1526 B or equivalent.
3. Connector test set V.A.G 1594 C.

Test requirements

Scheme 1217

1. Battery voltage at least 12.5 V.

Scheme 1218

1. Fuse 1 of right fuse panel in center bracket of instrument panel - 2 - is OK.

Scheme 1219

1. Vehicles with MPI engine: Fuel Pump (FP) Relay -J17- in relay and fuse carrier, position - 2 - in left electronics box is OK.
2. Vehicles with FSI engine: Fuel Pump (FP) Control Module -J538- OK; checking. --> «20 - FUEL SUPPLY»(/audi/a6/6-2004-2008/remont/fuel-system/#fuel-supply-system)
3. Fuel filter OK.
4. Ignition switched off.

Test sequence

1. Remove rear seat bench --> «72 - SEAT - FRAMES»(/audi/a6/6-2004-2008/remont/gauges-instrument-panels/#body-interior) .

1. Remove cover for right locking flange - arrows -.

1. Disconnect electrical harness connector - arrow - at locking flange.

Scheme 1220

1. Connect remote control V.A.G 1348/3 A with connection V.A.G 1348/3-2 to contact - 1 - using an adapter cable from connector test set V.A.G 1594 C.
2. Connect contact - 5 - to vehicle Ground (GND) using a jumper cable from connector test set V.A.G 1594 C.
3. Connect alligator clip to vehicle battery positive (+).
4. Press switch on remote control.

1. Running noise of pump must be audible.

Note. The Fuel Pump (FP) runs quietly. Avoid surrounding noises while testing the fuel pump.

If no operating noise can be heard

Scheme 1221

1. Remove fuel delivery unit. --> «Fuel delivery unit, removing and installing»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__fuel-delivery-unit-removing-and-installing) .
2. Check if electrical wiring between flange and fuel pump is connected and has continuity.

If no malfunction is detected in wiring, Fuel Pump (FP) is faulty. Replace fuel pump.

1. Install fuel delivery unit. --> «Fuel delivery unit, removing and installing»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__fuel-delivery-unit-removing-and-installing) .

Fuel Pump (FP), checking delivery quantity

Special tools, testers and auxiliary items required

1. Pressure gauge set V.A.G 1318.
2. Adapter V.A.G 1318/11.
3. Adapter V.A.G 1318/12.
4. Remote control V.A.G 1348/3 A with adapter cable V.A.G 1348/3-3 or equivalent.

1. Measuring container, fuel-resistant.

Test requirements

1. Battery voltage at least 12.5 V.

1. Vehicles with MPI engine: Fuel Pump (FP) Relay - J17- in relay and fuse carrier, position - 2 - in left electronics box is OK.
2. Vehicles with FSI engine: Fuel Pump (FP) Control Module -J538- OK; checking --> «20 - FUEL SUPPLY»(/audi/a6/6-2004-2008/remont/fuel-system/#fuel-supply-system) .
3. Fuel filter OK.
4. Fuel tank at least 1 / 4 filled.

1. Ignition switched off.

Test sequence

1. Remove rear seat bench --> «72 - SEAT - FRAMES»(/audi/a6/6-2004-2008/remont/gauges-instrument-panels/#body-interior) .

1. Remove bolts - arrows - and remove cover for right locking flange.

1. Disconnect electrical connector - arrow - at locking flange.

Scheme 1222

1. Connect remote control V.A.G 1348/3 A with connection V.A.G 1348/3-3 to contact - 5 - using an adapter cable from connector test set V.A.G 1594 C.
2. Using insulating tape, tape over second contact of remote control connection V.A.G 1348/3-3 to prevent a short circuit - arrow -.
3. Route switch of remote control V.A.G 1348/3 A forward into engine compartment.
4. Connect alligator clip to Ground (GND) point in engine compartment.

1. Connect contact - 1 - to battery positive terminal (B+) using a self-made jumper cable. For safety reasons, install a fuse - A - (10 A) in wiring.
2. Remove fuel filler cap from fuel filler tube.
3. Pull rear engine cover off - arrows -.
4. Pull resonator - 1 - upward - arrow - and unclip it.

Scheme 1223

1. Disconnect fuel line - arrow -.

Scheme 1224

1. Connect pressure gauge V.A.G 1318 to fuel line using adapter V.A.G 1318/11 and V.A.G 1318/12.
2. Connect assisting hose - arrow - to pressure gauge and hold it in a measuring container.
3. Open shut-off valve of pressure gauge. Lever points in direction of flow.
4. Generate pressure in fuel system by pressing switch of remote control and slowly closing shut-off valve of pressure gauge.

1. Specification: 4 bar positive pressure.

Note. From this point on do not move position of shut-off tap.

1. Empty measuring container.
2. Press switch on remote control for 15 seconds.

Scheme 1225

1. Compare quantity of fuel delivered with minimum delivery rate in diagram (cm 3 /15s).

Note. Voltage at fuel pump with engine stopped and pump running is approx. 2 volts less than battery voltage.

If minimum delivery quantity is not obtained, the following malfunctions may be present

1. Fuel lines pinched.
2. Fuel filter clogged.
3. Fuel pump faulty.

Assembly is performed in reverse order.

Tightening torque

Fuel system, bleeding

To prevent damage to the catalytic converter the fuel system must be bled after repair work on fuel lines or on the fuel filter.

Fuel system, bleeding --> 24 - MULTIPORT FUEL INJECTION (MFI) .

Scheme 1226

1 - 19 Nm

2 - Cover

1. For EVAP canister.

3 - Sealing piece

4 - Vent line

1. From fuel tank filler tube.
2. To remove, press release ring on EVAP canister.

5 - Vent line

1. To Evaporative Emission (EVAP) Canister Purge Regulator Valve N80.
2. To remove, press release ring on EVAP canister.
3. Clipped in on fuel tank.

6 - Air filter housing

1. For Leak Detection Pump (LDP) V144.
2. No maintenance schedule.

7 - 4 Nm

8 - Vacuum line

1. For engine and Leak Detection Pump (LDP) V144.

9 - Cable tie

1. To fasten vacuum line to bracket for leak detection pump.

10 - Leak Detection Pump (LDP) V144.

1. Location: In left rear wheelhousing behind liner
2. Checking --> «Leak Detection Pump (LDP) -V144- , checking»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__leak-detection-pump-ldp-v144) .

11 - Electrical connector

1. Black

12 - Connecting hose

1. Leak detection pump/EVAP filter.
2. Pressure side.

13 - EVAP filter

14 - Connecting hose

1. Leak detection pump/air filter.

15 - Connecting line

1. EVAP filter/EVAP canister.

16 - EVAP canister

1. Location: Bottom of spare wheel well.

Scheme 1227

1 - Throttle valve control module J338

2 - Evaporative Emission (EVAP) Canister Purge Regulator Valve N80

1. Location: In engine compartment right front.
2. Checking --> «Evaporative Emission (EVAP) Canister Purge Regulator Valve N80 , checking»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__evaporative-emission-evap-canister-purge-regulator) .

3 - Vent line

1. From EVAP canister to Evaporative Emission (EVAP) Canister Purge Regulator Valve N80.
2. Installed location: On right beneath vehicle floor.
3. Secured to fuel tank in fuel tank area.

4 - Vent line

1. To gravity valve on fuel tank.

5 - EVAP canister

1. Location: Bottom of spare tire wheel well.

6 - Connecting hose

1. Leak Detection Pump (LDP) V144/EVAP canister.
2. Pressure side.

7 - Air filter housing

1. For Leak Detection Pump (LDP) V144.

8 - Leak Detection Pump (LDP) V144.

1. Location: In left rear wheelhousing behind liner.
2. Checking --> «Leak Detection Pump (LDP) -V144- , checking»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__leak-detection-pump-ldp-v144) .

9 - Vacuum line

1. For engine and Leak Detection Pump (LDP) V144.

EVAP system, leak detection

Function

The leak detection system recognizes leaks in the complete fuel system, including the fuel tank, EVAP canister and the Evaporative Emission (EVAP) Canister Purge Regulator Valve N80.

On the mechanical side, the leak detection system consists mainly of a vacuum-driven diaphragm pump equipped with a reed contact on the actuation rod of the pump diaphragm. The pump is supplied with vacuum via the engine intake stroke.

1. When leak detection is activated, the diaphragm pump pumps the fuel system up to 20 to 30 mbar. The pump diaphragm is then moved out so that the reed contact at the operating rod remains in the "open" position.
2. During leak diagnosis, the reed contact is monitored to check if it remains open within 10 seconds. This indicates the system is sealed.
3. If the pressure falls (indicating a leak), the diaphragm moves back and the reed contact closes.
4. If the reed contact closes within 10 seconds of leak detection time, a further test is performed: In this case the diaphragm pump pumps four times again. The Engine Control Module (ECM) J623 measures the time for each of the four pumps until the reed contact is closed again. From that, the control module can recognize a "small leak" (greater than 1 mm in diameter) or a "large leak".

Leak diagnosis is activated automatically shortly following every engine start. If a malfunction is determined, an entry is made to the Diagnostic Trouble Code (DTC) memory. The Malfunction Indicator Lamp (MIL) K83 in the instrument cluster lights up if the malfunction is recognized for two subsequent starts.

Evaporative Emission (EVAP) canister system, checking for proper seal

Note. Secure all hose connections using hose clamps appropriate for the model type . Replace seals and gaskets when performing repair work.

Test sequence

1. Connect diagnostic tester. --> «Diagnostic tester, connecting»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk) .
2. Start engine and let run at idle for at least 15 minutes.
3. In diagnostic function 33 - OBD, select "Diagnostic mode 8: Tank leak test".
4. Select "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-tightness test, switch the ignition off, start the engine again, and let it run at idle.

If specified value is obtained

1. End diagnosis and switch ignition off.

If specified value is not obtained

Checking fuel supply and tank ventilation systems for leaks

1. Check whether the fuel filler cap of the fuel tank was completely sealed for test.
2. Check whether the seal of the fuel filler cap was damaged or crimped. Replace if necessary.
3. Fold forward right backrest of the rear seat, if necessary.

Scheme 1228

1. Release retaining tabs - arrows -.

Scheme 1229

1. Fold retaining tabs open - 1 - and - 3 - toward rear.
2. Fold cover - 2 - toward front - arrow -.

Scheme 1230

1. Unbolt cover - arrows -.
2. Remove rear seat bench --> «72 - SEAT - FRAMES»(/audi/a6/6-2004-2008/remont/gauges-instrument-panels/#body-interior) .

1. Remove bolts - arrows - and remove cover for locking flange, left and right.
2. Check whether the seals under the locking flanges are OK and the union nuts are properly tightened on the fuel tank. Also check fuel line connections.
3. Visually check all hose connections of the fuel supply system and replace any leaking lines, e.g

1. Line from the EVAP canister to Evaporative Emission (EVAP) Canister Purge Regulator Valve N80.
2. Lines from EVAP canister to Leak Detection Pump (LDP) V144.
3. Line from fuel tank to the EVAP canister (below cover for EVAP canister).
4. Lines for the tank ventilation (beneath right rear wheel housing liner).

1. Fuel lines to engine.

Note. Leaks at the lines and components of the fuel tank ventilation system can sometimes be located using a non-flammable, environmentally compliant leak detection spray. Initiate the leak diagnosis several times in sequence to build up pressure in the system. At leaking areas, bubbles will form.

1. Repeat function test.

If a malfunction persists

1. Perform a visual inspection on fuel system components and tank ventilation system.

1. Fuel tank
2. EVAP canister
3. Leak Detection Pump (LDP) V144
4. Evaporative Emission (EVAP) Canister Purge Regulator Valve N80

Note. Due to the form or function of the components, leaking areas may not always be localized by spraying on the leak detection spray. It may be necessary to clamp off the relevant component using Hose Clamps Up To 25 mm Dia. 3094 and initiate the tank leak detection diagnostic. If the leak is no longer indicated, the component that was clamped off is faulty. If clamped off directly at the leak detection pump and a leak is still indicated, the leak detection pump itself is leaking.

Final procedures

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

1. Check DTC memory.
2. If necessary, erase DTC memory.
3. If DTC memory was erased, generate readiness code.

1. End diagnosis and switch the ignition off.

Evaporative Emission (EVAP) Canister Purge Regulator Valve N80 , checking

Special tools, testers and auxiliary items required

1. Multimeter V.A.G 1526 or equivalent.
2. Adapter Cable (121-Point) VAG1598/31.

Test requirements

1. The fuse for the Evaporative Emission (EVAP) Canister Purge Regulator Valve N80 OK.
2. The Fuel Pump (FP) OK, checking. --> «Fuel Pump (FP), checking delivery quantity»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__fuel-pump-fp-checking-delivery-quantity) .
3. The ignition switched off.

Note. Voltage for the Evaporative Emission (EVAP) Canister Purge Regulator Valve N80 is supplied via the Motronic Engine Control Module (ECM) Power Supply Relay J271.

Procedure

Scheme 1231

1. Remove rear engine cover - arrows -.

Scheme 1232

1. Disconnect electrical harness connector - 3 - from Evaporative Emission (EVAP) Canister Purge Regulator Valve N80.

Scheme 1233

Checking internal resistance

1. Using the multimeter V.A.G 1526 or equivalent, check the resistance between the terminals of the Evaporative Emission (EVAP) Canister Purge Regulator Valve N80.

Specified value: 22.0 to 30.0 ohms.

If specified value is not obtained

1. Replace Evaporative Emission (EVAP) Canister Purge Regulator Valve N80.

Checking voltage supply

Scheme 1234

If specification is obtained

1. Using the multimeter V.A.G 1526 or equivalent, check electrical harness connector terminal 1 to 2 for voltage.
2. Operate starter briefly.

Specified value: aprox. battery voltage.

If there is no voltage

1. Using the multimeter V.A.G 1526 or equivalent, check the electrical harness connector terminal voltage.

1. Operate starter briefly.

Specified value: aprox. battery voltage.

If there is no voltage again

1. Check wiring connection from electrical harness connector terminal 1 to Leak Detection Pump (LDP) -V144- terminal 3 for an open circuit.

Specified value: Wire resistance max 1.5 ohms.

If specification is not obtained

1. If necessary, repair faulty wiring connection.

If voltage supply is OK

Check Ground (GND) activation

1. Using multimeter V.A.G 1526 or equivalent, check electrical harness connector for voltage.

1. Operate starter briefly.

Specified value: aprox. battery voltage.

1. Switch ignition off.

If specified value is not obtained

1. Connect Adapter Cable (121-Point) VAG1598/31 to wiring harness of the Engine Control Module (ECM) J623 ; the ECM is not connected. --> «Test box, connecting for wiring and component test»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk)
2. Using multimeter V.A.G 1526 or equivalent, the following wire connection for open circuit.

Specified value: Wire resistance max 1.5 ohms.

If specification is not obtained

1. Check wiring for a short circuit to Battery positive (+) or an open circuit.
2. If necessary, repair the faulty wiring connection.

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

If specification is obtained

1. Replace Engine Control Module (ECM) J623. --> «Engine Control Module (ECM) J623 , replacing»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__engine-control-module-ecm-j623) .

Final procedures

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

1. Check DTC memory.
2. If necessary, erase DTC memory.
3. If DTC memory was erased, generate readiness code.

1. End diagnosis and switch the ignition off.

Leak Detection Pump (LDP) -V144- , checking

Special tools, testers and auxiliary items required

1. Multimeter V.A.G 1526 or equivalent.
2. Voltage tester V.A.G 1527 B or equivalent.
3. Connector test kit V.A.G 1594 C.
4. Adapter Cable (121-Point) VAG1598/31.

Test requirements

1. The Leak Detection Pump (LDP) V144 fuse OK..
2. The Fuel Pump (FP) OK.
3. The ignition switched off.

Procedure

Scheme 1235

1. Remove left rear wheel housing liner. --> «66 - EXTERIOR EQUIPMENT»(/audi/a6/6-2004-2008/remont/door-locks-anti-theft-systems/#body-exterior) .
2. Disconnect electrical harness connector - 3 -.

Scheme 1236

Checking internal resistance

1. Using Multimeter V.A.G. 1526 A or equivalent, check Leak Detection Pump (LDP) V144 for resistance as follows

If specifications are not obtained

1. Replace Leak Detection Pump (LDP) -V144-. --> «20 - FUEL SUPPLY»(/audi/a6/6-2004-2008/remont/fuel-system/#fuel-supply-system) .

If specified values are obtained

1. Check voltage supply of Leak Detection Pump (LDP) -V144-.

Scheme 1237

Checking voltage supply

Note. The voltage for the Leak Detection Pump (LDP) -V144- is supplied via the Engine Control Module (ECM) Power Supply Relay -J271-.

1. Using the Multimeter V.A.G. 1526 A or equivalent, check electrical harness connector for voltage as follows

1. Operate starter briefly.

Specified value: aprox. battery voltage.

1. Switch ignition off.

If specified value was not obtained

1. Using the Multimeter V.A.G. 1526 A or equivalent, check electrical harness connector terminal - 3 - via Fuel Metering Valve N290 to Engine Control Module (ECM) J623 for open circuit.
2. If necessary, repair wiring connection.

If no malfunction is found in wiring

Checking output wiring

1. Connect Adapter Cable (121-Point) VAG1598/31 to the wiring harness of the Engine Control Module (ECM) J623 ; the ECM is not connected. --> «Test box, connecting for wiring and component test»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk)
2. Using Multimeter V.A.G. 1526 A or equivalent, check following wire connections for an open circuit.

Specified value: Wire resistance max 1.5 ohms.

If specification is not obtained

1. Check wiring for a short circuit to Battery positive (+) or an open circuit.

If no malfunction is found in wiring

1. Replace Engine Control Module (ECM) J623. --> «Engine Control Module (ECM) J623 , replacing»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__engine-control-module-ecm-j623) .

Assembly is performed in reverse order of removal. Note the following

1. Install left rear wheel housing liner. --> «66 - EXTERIOR EQUIPMENT»(/audi/a6/6-2004-2008/remont/door-locks-anti-theft-systems/#body-exterior) .

Final procedures

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

1. Check DTC memory.
2. If necessary, erase DTC memory.
3. If DTC memory was erased, generate readiness code.

1. End diagnosis and switch ignition off.

Functions of Electronic Power Control "EPC" System

For vehicles equipped with EPC, 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) J623 through the Throttle Position (TP) Sensor G79/Accelerator Pedal Position Sensor 2 G185 located in the accelerator pedal module.

The accelerator pedal position (drivers intention) is the main input unit for the Engine Control Module (ECM) J623.

Operation of the throttle valve occurs via an electric motor (throttle valve actuator) in the Throttle Valve Control Module J338. 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 Engine Control Module (ECM) J623.

With ignition switched on and engine off, the Engine Control Module (ECM) J623 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 Engine Control Module (ECM) J623 can open or close the throttle valve independently of the sensor for accelerator pedal position.

This means, 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) J623 via the optimal combination of throttle valve diameter and boost pressure.

It would be incorrect to think that "EPC" consists of only one or two components. EPC is much more of a system containing all components that contribute to recognizing, controlling and monitoring the position of the throttle valve, e.g. the Throttle Position (TP) Sensor G79/Accelerator Pedal Position Sensor 2 G185 , Throttle Valve Control Module J338 , Electronic Power Control (EPC) Warning Lamp K132 , and the Engine Control Module (ECM) J623.

Scheme 1238

1 - Accelerator pedal module

1. With Throttle Position (TP) Sensor G79/Accelerator Pedal Position Sensor 2 G185.
2. Removing and installing --> «Accelerator pedal module, removing and installing»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__accelerator-pedal-module-removing-and-installing) .

2 - Electrical connector

3 - 9 Nm

Throttle Position (TP) Sensor G79/Accelerator Pedal Position Sensor 2 G185 , checking

Special tools, testers and auxiliary items required

1. Hand multimeter V.A.G 1526 or equivalent.
2. Adapter Cable (121-Point) VAG1598/31.

Note. The Throttle Position (TP) Sensor G79/Accelerator Pedal Position Sensor 2 G185 is located in the accelerator pedal module and communicate the drivers intensions to the Engine Control Module (ECM) J623 completely independently of each other. Both sensors are located in the accelerator pedal module and replaced as an entire assembly.

Test requirements

1. The fuses for engine electronics OK..
2. The battery voltage must be at least 12.5 Volts.
3. All electrical consumers such as, for example, lights and rear window defroster must be switched off.
4. The parking brake must be applied, otherwise daytime running lights are switched on.

1. On vehicles with an automatic transmission, the selector lever must be in position "P" or "N".
2. If the vehicle is equipped with an A/C system, it must be switched off.
3. The Ground (GND) connections between engine and body must be OK.

Procedure

Scheme 1239

1. Remove left knee bolster --> «68 - INTERIOR EQUIPMENT»(/audi/a6/6-2004-2008/remont/gauges-instrument-panels/#body-interior) .
2. Disconnect electrical harness connector - 2 -.

Checking voltage supply

1. Switch ignition on.

Scheme 1240

1. Using the Multimeter V.A.G. 1526 A or equivalent, check the following wiring connections for voltage.

1. Switch ignition off.

If specified values are not obtained

Checking wiring connections

1. Connect Adapter Cable (121-Point) VAG1598/31 to wiring harness of the Engine Control Module (ECM) J623 ; the ECM is not connected. --> «Test box, connecting for wiring and component test»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk) .

1. Using the Multimeter V.A.G. 1526 A or equivalent, check the following wiring connections for open circuit.

Specified value: Wire resistance max 1.5 ohms.

If specification is not obtained

1. Check wiring for a short circuit to Battery positive (+) or an open circuit.
2. If necessary, repair faulty wiring connection.

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

1. Replace Throttle Position (TP) Sensor G79/Accelerator Pedal Position Sensor 2 G185. --> «Accelerator pedal module, removing and installing»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__accelerator-pedal-module-removing-and-installing) .

If no malfunction is detected in the wiring and if voltage supply was not OK

1. Replace Engine Control Module (ECM) J623. --> «Engine Control Module (ECM) J623 , replacing»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__engine-control-module-ecm-j623) .

Assembly is performed in reverse order of removal. Note the following

1. Install left knee bolster --> «68 - INTERIOR EQUIPMENT»(/audi/a6/6-2004-2008/remont/gauges-instrument-panels/#body-interior) .

Final procedures

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

1. Check DTC memory.
2. If necessary, erase DTC memory.
3. If DTC memory was erased, generate readiness code.

Accelerator pedal module, removing and installing

Removing

Scheme 1241

1. Remove left knee bolster --> «68 - INTERIOR EQUIPMENT»(/audi/a6/6-2004-2008/remont/gauges-instrument-panels/#body-interior) .
2. Disconnect electrical harness connector - 2 -.
3. Remove bolts - 1 - and - 3 -.
4. Remove accelerator pedal module.

Installing

Installation is performed in reverse order of removal. Note the following

Tightening torque

1. Install left knee bolster --> «68 - INTERIOR EQUIPMENT»(/audi/a6/6-2004-2008/remont/gauges-instrument-panels/#body-interior) .

Note. If the Throttle Position (TP) Sensor G79/Accelerator Pedal Position Sensor 2 G185 or the Engine Control Module (ECM) J623 is replaced in a vehicle with an automatic transmission, the kick-down function must be adapted.

Procedure

1. Switch ignition on.
2. Press accelerator pedal down past the kick down point and hold for at least 20 seconds.
3. Release accelerator pedal.
4. Switch ignition off.

To reduce the risk of personal injury and/or damage to the fuel injection and ignition system. Note the following

1. Always switch off ignition before disconnecting or connecting lines of the fuel injection and ignition system, including test leads.
2. During some of the tests, a Diagnostic Trouble Code (DTC) may be recognized and stored by the control module. At the end of all tests and repairs, the DTC memory should be checked and, if necessary, erased. After erasing the DTC memory, a readiness code must be generated for the engine control module.
3. Always switch ignition off before cleaning engine.

Observe the following if test and measuring instruments are required during a test drive

Rules of cleanliness

Even minor contaminations can lead to malfunctions in the fuel injection system. When working on the fuel supply/injection system, pay careful attention to the following rules for cleanliness

1. Thoroughly clean all unions and adjacent areas with engine or brake cleaner and dry before disconnecting.
2. Plug open lines and connections immediately with appropriate protective caps.
3. Place removed parts on a clean surface and cover. Use lint-free cloths.
4. Install clean components: Remove replacement parts immediately prior to installation. Do not use parts that have been stored unpackaged (e.g. in tool boxes etc.).

1. When the system is open: Do not work with compressed air. Do not move vehicle unless absolutely necessary.
2. Separated electrical connectors: Protect from dirt and moisture. Make sure connections are dry when re-connecting.

Technical data

Component locations, overview

Components A through G are not depicted in the illustration

Scheme 1242

1 - Engine Control Module (ECM) J623

1. Component location: in E-box in right plenum chamber.
2. Removing and installing --> «Engine Control Module (ECM) J623 , removing and installing»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__engine-control-module-ecm-j623) .
3. Replacing --> «Engine Control Module (ECM) J623 , replacing»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__engine-control-module-ecm-j623) .

2 - Mass air flow (MAF) sensor G70 with intake air temperature (IAT) sensor G42

1. Checking --> «Mass Air Flow (MAF) Sensor G70 , checking»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__mass-air-flow-maf-sensor-g70) .

3 - Valve 1 for camshaft adjustment N205

1. Checking --> «Camshaft Adjustment Valve , checking»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__camshaft-adjustment-valve-checking) .

4 - Connector strip

1. Connector assignment «Connector strip on right side of bulkhead»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk)

5 - Camshaft Position (CMP) sensor G40

1. Cylinder bank 1
2. Checking --> «Camshaft Position (CMP) Sensors , checking»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__camshaft-position-cmp-sensors-checking) .

6 - Engine coolant temperature (ECT) sensor G62

1. Checking --> «Engine Coolant Temperature (ECT) Sensor G62 , checking»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__engine-coolant-temperature-ect-sensor-g62) .

7 - Throttle valve control module J338

1. With Throttle Drive (for Electronic Power Control (EPC)) G186 , Throttle Drive Angle Sensor 1 (for Electronic Power Control (EPC)) G187 and Throttle Drive Angle Sensor 2 (for Electronic Power Control (EPC)) G188.
2. Checking --> «Throttle Valve Control Module J338 , checking»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__throttle-valve-control-module-j338) .

8 - Evaporative emission (EVAP) canister purge regulator valve N80

1. Checking --> «Evaporative Emission (EVAP) Canister Purge Regulator Valve N80 , checking»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__evaporative-emission-evap-canister-purge-regulator) .

9 - Oil pressure switch F1

1. «Engine viewed from rear»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk)

10 - Camshaft position (CMP) sensor 2 G163

1. Cylinder bank 2
2. Checking --> «Camshaft Position (CMP) Sensors , checking»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__camshaft-position-cmp-sensors-checking) .

11 - Connector strip

1. Connector assignment
2. «Connector strip beneath coolant reservoir»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk)

12 - Valve 2 for camshaft adjustment N208

1. Checking --> «Camshaft Adjustment Valve , checking»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__camshaft-adjustment-valve-checking) .

13 - Ignition coils with power output stages

1. Cylinder bank 2
2. To remove, use puller for ignition coil T10094.
3. Checking --> «Ignition Coil with Power Output Stage N70, N127, N291, N292, N323, N324, N325, N326 , checking»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__ignition-coil-with-power-output-stage) .

14 - 3-pin harness connector

1. For knock sensor (KS) 3 G198.
2. For knock sensor (KS) 4 G199.

15 - Secondary Air Injection (AIR) Solenoid Valve N112

1. «Engine viewed from front»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk)
2. Checking --> «Secondary Air Injection (AIR) Solenoid Valve -N112- , checking»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__secondary-air-injection-air-solenoid-valve) .

16 - Intake Manifold Change-Over Valve N156

1. «Engine viewed from front»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk)

17 - 3-pin harness connector

1. For knock sensor (KS) 1 G61.
2. For knock sensor (KS) 2 G66.
3. «Engine viewed from front»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk)

18 - Ignition coils with power output stages

1. Cylinder bank 1
2. To remove, use puller for ignition coil T10094.
3. Checking --> «Ignition Coil with Power Output Stage N70, N127, N291, N292, N323, N324, N325, N326 , checking»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__ignition-coil-with-power-output-stage) .

19 - Intake air switch-over valve N335

1. For controlling a flap in air filter housing
2. The intake air switch-over valve N335 is located behind air filter housing. The air filter housing must be completely removed to test the valve.

20 - Secondary air injection (AIR) pump motor V101

1. Front bottom in driving direction.
2. Refer to --> «Secondary air injection (AIR) pump motor V101»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk)
3. Checking --> «Voltage supply for Secondary Air Injection (AIR) Pump Motor -V101- , checking»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__voltage-supply-for-secondary-air-injection) .

A - Throttle position (TP) sensor G79 and Accelerator Pedal Position Sensor 2 G185

1. In footwell on accelerator pedal (both sensors are integrated into one housing).
2. Checking --> «Throttle Position (TP) Sensor G79/Accelerator Pedal Position Sensor 2 G185 , checking»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__throttle-position-tp-sensor-g79accelerator-pedal) .

B - Brake light switch F

1. In footwell on pedal mount near brake pedal.

C - Fuel pump (FP) relay J17

1. In 3-pin relay carrier in plenum chamber, left side, relay position 2.
2. «Component located on 3-pin relay carrier in left plenum chamber»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk)
3. Checking --> «Fuel Pump (FP) Relay J17 , checking»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__fuel-pump-fp-relay-j17) .

D - Motronic engine control module (ECM) power supply relay J271

1. In 3-pin relay carrier in plenum chamber, left side, relay position 3.
2. «Component located on 3-pin relay carrier in left plenum chamber»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk)
3. Checking --> «Motronic Engine Control Module (ECM) Power Supply Relay J271 , checking»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__motronic-engine-control-module-ecm-power) .

E - Secondary air injection (AIR) pump relay J299

1. In 4-pin relay carrier in E-box, in right side of plenum chamber, relay position 3.
2. «Component located on 4-pin relay carrier in E-box of right plenum chamber»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk)
3. Checking --> «Secondary Air Injection (AIR) Pump Relay -J299- , checking»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__secondary-air-injection-air-pump-relay) .

F - Data Link Connector (DLC)

1. Located in knee bolster on drivers side.

G - Engine speed (RPM) sensor G28

1. In transmission housing over ring gear.
2. Checking --> «Engine Speed (RPM) Sensor G28 , checking»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__engine-speed-rpm-sensor-g28) .

Scheme 1243

2 - Fuel pump (FP) relay J17.

3 - Motronic engine control module (ECM) power supply relay J271.

Scheme 1244

3 - Secondary air injection (AIR) pump relay J299.

Scheme 1245

1 - 6-pin connection for heated oxygen sensor (HO2S) G39 and oxygen sensor (O2S) heater Z19 before catalytic converter of bank 1.

2 - 2-pin connection for bank 1 valve 1 for camshaft adjustment N205.

3 - 4-pin connection for oxygen sensor (O2S) behind three way catalytic converter (TWC) G130 and oxygen sensor (O2S) heater 1 (behind three way catalytic converter (TWC)) Z29 of bank 1.

Scheme 1246

1 - 6-pin connection for heated oxygen sensor (HO2S) 2 G108 and oxygen sensor (O2S) heater 2 Z28 before catalytic converter of bank 2.

2 - 3-pin connection (gray) for engine speed (RPM) sensor G28.

3 - 2-pin connection for bank 2 valve 2 for camshaft adjustment N208.

4 - 4-pin connection for oxygen sensor (O2S) 2 behind three way catalytic converter (TWC) G131 and oxygen sensor (O2S) heater 2 (behind three way catalytic converter (TWC)) Z30 of bank 2.

Scheme 1247

1 - Vacuum diaphragm for intake manifold change-over.

2 - Knock sensor (KS) 1 G61.

3 - Knock sensor (KS) 2 G66.

4 - Intake Manifold Change-Over Valve N156.

5 - Secondary Air Injection (AIR) Solenoid Valve N112.

6 - Knock sensor (KS) 3 G198.

7 - Knock sensor (KS) 4 G199.

Scheme 1248

1 - Valve 2 for camshaft adjustment N208.

2 - Camshaft position (CMP) sensor 2 G163 cylinder bank 2.

3 - Oil pressure switch F1.

4 - Throttle valve control module J338.

5 - Engine coolant temperature (ECT) sensor G62.

6 - Camshaft position (CMP) sensor G40 cylinder bank 1.

7 - Valve 1 for camshaft adjustment N205.

Scheme 1249

1. Lower right, in driving direction.

Scheme 1250

1 - Vent hose

2 - Intake air switch-over valve N335

3 - Lower part of air filter housing

1. Clean air filter housing of salt residue, dirt and leaves.

4 - Rubber grommet

5 - Air duct

1. Check air duct for dirt and leaves.

6 - 1.5 Nm

7 - Air duct

1. Check air duct for dirt and leaves.

8 - Connection

9 - Air duct hose to Throttle Valve Control Module J338

1. With resonator.

10 - Wiring router

11 - O-ring

1. Always replace.

12 - 1.5 Nm

1. For securing air filter element.

13 - Upper part of air filter housing

1. Clean air filter housing of salt residue, dirt and leaves.

14 - Air duct

1. Clipped into upper part of air filter housing.

15 - Air filter element

1. Always use a genuine air filter element.

16 - O-ring

1. Always replace.

17 - Spreader clip

18 - Grommet

Scheme 1251

1 - Intake manifold

2 - O-rings

1. For fuel injectors.
2. Always replace.

3 - 10 Nm

4 - Fuel supply line

1. Tighten union nut to 25 Nm.

5 - Fuel rail

6 - Pressure regulator valve

1. For crankcase ventilation.

7 - 10 Nm

1. Fasten diagonally in steps.

8 - Lifting eye

9 - 23 Nm

10 - Gasket

1. For intake manifold.
2. Always replace.

11 - Locking pin - 0.6 Nm

Fuel injectors, removing and installing

Removing

Scheme 1252

1. Remove front engine cover - arrows -1- and -2 -.

1. Remove rear engine cover - arrows -.

Scheme 1253

1. Remove resonator - 1 - in direction of - arrow - from air duct hose.
2. Disconnect electrical connectors from fuel injectors.

Scheme 1254

1. Open threaded connection - arrow - and catch any escaping fuel using a shop rag.

Scheme 1255

1. Disconnect fuel supply line - arrow - from fuel rail.

Remove bolts - arrows - securing fuel rail to intake manifold.

1. Remove fuel rail with fuel injectors attached, from intake manifold - arrows -.

Note. Protect the removed fuel injectors from contamination.

1. Disengage retaining clip and remove fuel injector from fuel rail.

Installing

1. Installation is in reverse order of removal. Note the following

1. Replace all O-rings at all opened connections. (Never remove the plastic cap from the valve head to replace the front O-ring, lift the O-ring off over the plastic cap).
2. Lightly lubricate new O-rings with clean engine oil.
3. Make sure fuel injectors are in place and seated correctly.
4. Check clip for unobstructed fitting.

1. Place fuel rail with secured fuel injectors onto intake manifold, and apply uniform pressure to seat it in the intake manifold.

Tightening torque

Oxygen Sensor (O2S) Heater for Heated Oxygen Sensor (HO2S) before catalytic converter, checking

This procedure is used to check Oxygen Sensor (O2S) Heater Z19 and Oxygen Sensor (O2S) Heater Z28.

Special tools, testers and auxiliary items required

1. Multimeter V.A.G 1526 or equivalent.
2. Adapter Cable (121-Point) VAG1598/31.

Test requirements

1. The fuse for the oxygen sensor heating OK..
2. The Ground (GND) connections at the engine and transmission OK.
3. The Fuel Pump (FP) Relay J17 OK. --> «Fuel Pump (FP) Relay J17 , checking»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__fuel-pump-fp-relay-j17) .
4. The ignition is switched off.

Note. Voltage for Oxygen Sensor (O2S) Heater -Z19- (bank 1, sensor 1) and Oxygen Sensor (O2S) Heater -Z28- (bank 2, sensor 1) is supplied via the Fuel Pump (FP) Relay J17. Bank 1 = cylinder bank 1 in direction of travel, right; Bank 2 = cylinder bank 2 in direction of travel, left. When servicing terminals in the electrical harness connector of the oxygen sensors, use gold-plated terminals only.

Procedure

1. Disconnect 6-pin electrical harness connector - 1 - from the Heated Oxygen Sensor (HO2S) -G39- and Oxygen Sensor (O2S) Heater -Z19- (bank 1, sensor 1).

To test Oxygen Sensor (O2S) Heater -Z28- (bank 2, sensor 1), perform the following steps

Scheme 1256

1. Remove screw - arrow - retaining coolant reservoir.

1. Disconnect electrical connector from Engine Coolant Level (ECL) Warning Switch F66 at the bottom of coolant reservoir and set aside coolant reservoir with coolant hoses - 1 - and - 2 - connected.
2. Disconnect 6-pin electrical harness connector - 1 - from Heated Oxygen Sensor (HO2S) -G108- and Oxygen Sensor (O2S) Heater -Z28- (bank 2, sensor 1).

Scheme 1257

Checking internal resistance

1. Using Multimeter V.A.G. 1526 A or equivalent, check Heated Oxygen Sensor (HO2S) terminals for resistance.

Specification: 2.5 to 10.0 ohms (at room temperature).

If specification is not obtained

1. Replace Heated Oxygen Sensor (HO2S) -G39- (bank 1, sensor 1) --> «Heated oxygen sensor (HO2S) G39 before catalytic converter, bank 1 (right), removing and installing»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk) or Heated Oxygen Sensor (HO2S) -G108- (bank 2, sensor 1) before catalytic converter --> «Heated oxygen sensor (HO2S) 2 G108 before catalytic converter, bank 2 (left), removing and installing»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__heated-oxygen-sensor-ho2s-2-g108) .

If specified value is obtained

Scheme 1258

Checking voltage supply

1. Using Multimeter V.A.G. 1526 A or equivalent, check electrical harness connector terminals for voltage.

1. Operate starter briefly.

Specified value: approx. battery voltage.

1. Switch ignition off.

If no voltage is present

1. Using Multimeter V.A.G. 1526 A or equivalent, check the following wiring connection for voltage.

1. Operate starter briefly.

Specified value: approx. battery voltage.

1. Switch ignition off.

If there is no voltage again

1. Using Multimeter V.A.G. 1526 A or equivalent, Check the wiring connection from the electrical harness connector terminal to the Fuel Pump (FP) Relay J17 terminal via fuse for resistance.

Wiring resistance: max. 1.5 ohms.

1. If necessary, repair wiring connection.
2. If wiring is OK

Check Ground (GND) activation

1. Using Multimeter V.A.G. 1526 A or equivalent, check electrical harness connector terminal to Ground (GND) for voltage.

1. Operate starter briefly (engine can also start)

Specified value: approx. battery voltage, possibly fluctuating.

1. Switch ignition off.

If specification is not obtained

1. Connect Adapter Cable (121-Point) VAG1598/31 to the wiring harness of the Engine Control Module (ECM) J623 ; the ECM is not connected. --> «Diagnostic tester, connecting»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk) .
2. Using Adapter Cable (121-Point) VAG1598/31 and Multimeter V.A.G 1526 A or equivalent, check the following wiring connections for an open circuit.

1. Oxygen Sensor (O2S) Heater -Z19- (bank 1, sensor 1)

1. Oxygen Sensor (O2S) Heater -Z28- (bank 2, sensor 1)

Specified value: Wire resistance max 1.5 ohms.

If specification is not obtained

1. Check wiring for a short circuit to Battery positive (+) or an open circuit.
2. If necessary, repair wiring connection.

If no malfunctions are detected

1. Replace Engine Control Module (ECM) J623. --> «Engine Control Module (ECM) J623 , replacing»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__engine-control-module-ecm-j623)

Assembly is performed in reverse order of removal. Note the following

Final procedures

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

1. Check DTC memory..
2. If necessary, erase DTC memory..
3. If DTC memory was erased, generate readiness code..

1. End diagnosis and switch the ignition off.

Oxygen Sensor (O2S) Heater for Oxygen Sensor (O2S) Behind Three Way Catalytic Converter (TWC) , checking

This procedure is used to check Oxygen Sensor (O2S) Heater Z29 and Oxygen Sensor (O2S) Heater Z30.

Special tools, testers and auxiliary items required

1. Multimeter V.A.G 1526 or equivalent.
2. Adapter Cable (121-Point) VAG1598/31.

Test requirements

1. The fuse for the oxygen sensor heating OK..
2. The Ground (GND) connections at the engine and transmission OK.
3. The Fuel Pump (FP) Relay J17 OK. --> «Fuel Pump (FP) Relay J17 , checking»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__fuel-pump-fp-relay-j17) .
4. The ignition is switched off.

Note. Voltage for Oxygen Sensor (O2S) Heater -Z29- (bank 1, sensor 2) and Oxygen Sensor (O2S) Heater -Z30- (bank 2, sensor 2) is supplied via the Fuel Pump (FP) Relay J17. Bank 1 = cylinder bank 1 in direction of travel, right; Bank 2 = cylinder bank 2 in direction of travel, left. When servicing terminals in the electrical harness connector of the oxygen sensors, use gold-plated terminals only.

Procedure

1. Disconnect 4-pin electrical harness connector - 3 - from Heated Oxygen Sensor (HO2S) -G130- and Oxygen Sensor (O2S) Heater -Z29- (bank 1, sensor 2).

To test Oxygen Sensor (O2S) Heater -Z30- (bank 2, sensor 2), perform the following steps

1. Remove screw - arrow - retaining coolant reservoir.

1. Disconnect electrical connector from Engine Coolant Level (ECL) Warning Switch F66 at the bottom of the coolant reservoir and set aside coolant reservoir with coolant hoses - 1 - and - 2 - connected.
2. Disconnect the 4-pin electrical harness connector - 4 - from Heated Oxygen Sensor (HO2S) -G131- and Oxygen Sensor (O2S) Heater -Z30- (bank 2, sensor 2).

Scheme 1259

Checking internal resistance

1. Using Multimeter V.A.G. 1526 A or equivalent, check Heated Oxygen Sensor (HO2S) terminals for resistance.

Note. Terminals 2 and 3 are not called out in the graphic.

Specification: 2.5 to 10.0 ohms (at room temperature).

If specification is not obtained

1. Replace Heated Oxygen Sensor (HO2S) -G130- (bank 1, sensor 2) --> «Oxygen sensor (O2S) behind three way catalytic converter (TWC) G130 , bank 1 (right), removing and installing»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__oxygen-sensor-o2s-behind-three-way) or Heated Oxygen Sensor (HO2S) -G131- (bank 2, sensor 2) behind Three Way Catalytic Converter (TWC) --> «Oxygen Sensor (O2S) 2 Behind Three Way Catalytic Converter (TWC) G131 after catalytic converter, bank 2 (left), removing and installing»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__oxygen-sensor-o2s-2-behind-three) .

If specified value is obtained

Scheme 1260

Checking voltage supply

1. Using Multimeter V.A.G. 1526 A or equivalent, check electrical harness connector terminals for voltage.

1. Operate starter briefly.

Specified value: approx. battery voltage.

1. Switch ignition off.

If no voltage is present

1. Using Multimeter V.A.G. 1526 A or equivalent, check the following wiring connection for voltage.

1. Operate the starter briefly.

Specified value: approx. battery voltage.

1. Switch the ignition off.

If there is no voltage again

1. Using Multimeter V.A.G. 1526 A or equivalent, check wiring connection from the electrical harness connector terminal to the Fuel Pump (FP) Relay J17 terminal via fuse for an open circuit.

Wiring resistance: max. 1.5 ohms.

1. If necessary, repair wiring connection.
2. If wiring is OK

Check Ground (GND) activation

1. Using Multimeter V.A.G. 1526 A or equivalent, check electrical harness connector for voltage.

1. Operate starter briefly (engine can also start).

Specified value: approx. battery voltage, possibly fluctuating.

1. Switch ignition off.

If specification is not obtained

1. Connect Adapter Cable (121-Point) VAG1598/31 to the wiring harness of the Engine Control Module (ECM) J623 ; the ECM is not connected. --> «Diagnostic tester, connecting»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk) .
2. Using Adapter Cable (121-Point) VAG1598/31 and Multimeter V.A.G 1526 A or equivalent, check the following wire connection for an open circuit.

1. Oxygen Sensor (O2S) Heater -Z29- (bank 1, sensor 2)

1. Oxygen Sensor (O2S) Heater -Z30- (bank 2, sensor 2)

Specified value: Wire resistance max 1.5 ohms.

If specification is not obtained

1. Check wiring for a short circuit to Battery positive (+) or an open circuit.
2. If necessary, repair wiring connection.

If no malfunctions are detected

1. Replace Engine Control Module (ECM) J623. --> «Engine Control Module (ECM) J623 , replacing»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__engine-control-module-ecm-j623)

Assembly is performed in reverse order of removal. Note the following

Final procedures

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

1. Check DTC memory..
2. If necessary, erase DTC memory..
3. If DTC memory was erased, generate readiness code..

1. End diagnosis and switch ignition off.

Mass Air Flow (MAF) Sensor G70 , checking

Special tools, testers and auxiliary items required

1. Multimeter V.A.G 1526 or equivalent.
2. Adapter Cable (121-Point) VAG1598/31.

Test requirements

1. The fuse for Mass Air Flow (MAF) Sensor G70 OK..
2. The Ground (GND) connections at engine and transmission OK.
3. The Fuel Pump (FP) Relay J17 OK. --> «Fuel Pump (FP) Relay J17 , checking»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__fuel-pump-fp-relay-j17) .
4. The ignition is switched off.

1. The parking brake engaged.
2. The selector lever of automatic transmission in position "P" or "N".
3. All electrical consumers switched off (radiator fan must NOT run during test).
4. A/C switched off.

1. Coolant temperature at least 80° C.

Note. Voltage for the Mass Air Flow (MAF) Sensor G70 is supplied via the Fuel Pump (FP) Relay J17. When servicing terminals in the electrical harness connector of the Mass Air Flow (MAF) Sensor G70 , use gold-plated terminals only.

Checking function

1. Connect diagnostic tester. --> «Diagnostic tester, connecting»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk) .
2. Start engine and let run at idle.
3. In diagnostic function "33 - OBD" , select "Mode 1: Checking measured values."
4. Select desired measuring value "PID 16: Air flow quantity at Mass Air Flow (MAF) sensor -G70-."

Specified value: 3.5 to 7.0 g/s

1. End diagnosis and switch ignition off.

If specified value is not reached

1. Check intake air system for leaks (false air). --> «Intake system for leaks (false air), checking»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__intake-system-for-leaks-false-air) .
2. Check voltage supply and wire connections.

If specified value is exceeded

1. Eliminate engine load via additional equipment (A/C system/power-assist steering/generator).
2. Check voltage supply and wire connections.

Scheme 1261

Checking voltage supply

1. Disconnect electrical connector - 2 - from Mass Air Flow (MAF) Sensor G70.

Scheme 1262

1. Using Multimeter V.A.G. 1526 A or equivalent, check electrical harness connector for voltage.

1. Operate starter briefly (engine can also start).

Specified value: approx. battery voltage (B+).

1. Switch ignition off.

If specification is not obtained

1. Using Multimeter V.A.G. 1526 A or equivalent, check wiring connection from the electrical harness connector terminal to the Fuel Pump (FP) Relay J17 terminal via fuse for an open circuit.

Specified value: 1.5 ohms.

1. If necessary, repair the wiring connection.
2. If the wiring is OK

Check Ground (GND) activation

1. Using Multimeter V.A.G. 1526 A or equivalent, check electrical harness connector terminals 2 to 3 for voltage.
2. Operate starter briefly.

Specified value: approx. battery voltage (B+).

1. Switch ignition off.

If specification is not obtained

1. Repair the wiring connection.

If wiring is OK

1. Using Multimeter V.A.G. 1526 A or equivalent, check electrical harness connector for voltage.

1. Switch ignition on.

Specified value: about 5V.

1. Switch ignition off.

If specification is not obtained

Check wiring connections

1. Connect Adapter Cable (121-Point) VAG1598/31 to the wiring harness of the Engine Control Module (ECM) J623 ; the ECM is not connected. --> «Diagnostic tester, connecting»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk) .

1. Using Adapter Cable (121-Point) VAG1598/31 and Multimeter V.A.G 1526 A or equivalent, check the following wire connection for an open circuit.

Specified value: Wire resistance max 1.5 ohms.

If specification is not obtained

1. Check wiring for a short circuit to Battery positive (+) or an open circuit.
2. If necessary, wiring connection.

If no malfunction is found in wiring

1. Replace Mass Air Flow (MAF) Sensor G70.

Final procedures

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

1. Check DTC memory..
2. If necessary, erase DTC memory..
3. If DTC memory was erased, generate readiness code..

1. End diagnosis and switch ignition off.

Intake Air Temperature (IAT) Sensor G42 , checking

The Intake Air Temperature (IAT) Sensor G42 and Mass Air Flow (MAF) Sensor G70 are integrated into one unit and cannot be serviced separately.

Special tools, testers and auxiliary items required

1. Multimeter V.A.G 1526 or equivalent.
2. Adapter Cable (121-Point) VAG1598/31.

Test requirements

1. The fuse for the engine electronics OK..
2. The ignition is switched off.

Checking function

1. Connect diagnostic tester. --> «Diagnostic tester, connecting»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk) .
2. Start engine and let run at idle.
3. In diagnostic function "33 - OBD", select "Mode 1: Checking measured values".
4. Select 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.

1. End diagnosis and switch ignition off.

If specified values are nor obtained

Checking wiring connections

1. Disconnect electrical connector - 2 - from Mass Air Flow (MAF) Sensor G70.
2. Connect Adapter Cable (121-Point) VAG1598/31 to wiring harness of Engine Control Module (ECM) J623 ; the ECM is not connected. --> «Diagnostic tester, connecting»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk) .

1. Using Adapter Cable (121-Point) VAG1598/31 and Multimeter V.A.G 1526 A or equivalent, check the following wire connection for an open circuit.

Specified value: Wire resistance max 1.5 ohms.

If specification is not obtained

1. Check wiring for a short circuit to Battery positive (+), Ground (GND), or an open circuit.
2. If necessary, repair the wiring connection.

If no malfunction is found in the wiring

1. Replace Engine Control Module (ECM) J623 --> «Engine Control Module (ECM) J623 , replacing»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__engine-control-module-ecm-j623) .

If specification was obtained

1. Replace Mass Air Flow (MAF) Sensor G70.

Final procedures

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

1. Check DTC memory..
2. If necessary, erase DTC memory..
3. If DTC memory was erased, generate readiness code..

1. End diagnosis and switch ignition off.

Throttle Valve Control Module J338 , checking

The following components are located in the housing of the Throttle Valve Control Module J338

1. Throttle Drive (for Electronic Power Control (EPC)) G186 (This is an electric motor that is activated by the ECM. This electric motor opens the throttle valve against spring pressure).
2. Throttle Drive Angle Sensor 1 (for Electronic Power Control (EPC)) G187.
3. Throttle Drive Angle Sensor 2 (for Electronic Power Control (EPC)) 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) J623 fully independent of each other.

Special tools, testers and auxiliary items required

1. Multimeter V.A.G 1526 or equivalent.
2. Adapter Cable (121-Point) VAG1598/31.

Test requirements

1. Fuses for engine electronics OK..
2. Ground (GND) connections at engine and transmission OK.
3. Battery voltage at least 12.5 V.
4. The parking brake engaged.

1. The selector lever of automatic transmission in position "P" or "N".
2. All electrical consumers switched off (radiator fan must NOT run during test).
3. A/C switched off.
4. Coolant temperature at least 80° C.

Note. Use only gold-plated terminals when servicing terminals in throttle valve control module harness connector.

Checking function

1. Connect diagnostic tester. --> «Diagnostic tester, connecting»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk) .
2. Switch ignition on.
3. In diagnostic function "33 - OBD", select "Mode 1: Checking measured values".
4. Select desired measuring value "PID 17: Throttle valve position (absolute)".

Specified value: 12 to 16%.

1. Slowly depress accelerator pedal completely.

Specified value: The percentage display must increase uniformly.

1. Hold accelerator pedal fully depressed; in vehicles with automatic transmission, do not depress beyond kickdown point when doing this.

Specified value: 84 to 88%.

1. Switch ignition off.

If specified values are not obtained.

1. Check voltage supply and wiring connections of throttle valve control module «Checking voltage supply»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__checking-voltage-supply) . Pay particular attention to harness connectors that could be loose or corroded.
2. Check Throttle Position (TP) sensor. --> «Throttle Position (TP) Sensor G79/Accelerator Pedal Position Sensor 2 G185 , checking»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__throttle-position-tp-sensor-g79accelerator-pedal) .

Scheme 1263

1. Remove rear engine cover - arrows -.
2. Disconnect electrical harness connector - 6 - at Throttle Valve Control Module J338.
3. Switch ignition on.

1. Using Multimeter V.A.G. 1526 A or equivalent, check electrical harness connector for voltage.

1. Switch ignition off.

If specified values are not obtained.

Checking wiring connections

1. Connect Adapter Cable (121-Point) VAG1598/31 to wiring harness of Engine Control Module (ECM) J623 ; the ECM is not connected. --> «Diagnostic tester, connecting»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk) .

1. Using Adapter Cable (121-Point) VAG1598/31 and Multimeter V.A.G 1526 A or equivalent, check the following wire connections for an open circuit.

Specified value: Wire resistance max 1.5 ohms.

If specification is not obtained

1. Check wiring for a short circuit to Battery positive (+) or an open circuit.
2. If necessary, repair wiring connection.

If no malfunctions are detected in the wiring and if the voltage supply was OK

1. Replace Throttle Valve Control Module J338.
2. After replacing Throttle Valve Control Module J338 , it must be adapted. For this purpose switch on ignition for at least 30 seconds without starting the engine or depressing the accelerator pedal.
3. Switch ignition off.

The Engine Control Module (ECM) J623 now requires approx. 3 seconds to store learned value. At this time, the ignition must not be switched on again.

Assembly is performed in reverse order of removal. Note the following

Final procedures

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

1. Check DTC memory..
2. If necessary, erase DTC memory..
3. If DTC memory was erased, generate readiness code..

1. End diagnosis and switch ignition off.

Engine Speed (RPM) Sensor G28 , checking

Special tools, testers and auxiliary items required

1. Multimeter V.A.G 1526 or equivalent.
2. Adapter Cable (121-Point) VAG1598/31.

1. The Engine Speed (RPM) Sensor G28 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.

Test requirement

1. The fuses for engine electronics OK..
2. Battery voltage at least 12.5 V.
3. Ignition switched off.

Procedure

1. Disconnect electrical harness connector - 3 - from Engine Speed (RPM) Sensor G28.

Checking internal resistance

Scheme 1264

1. Using the Multimeter V.A.G. 1526 A or equivalent, check the Engine Speed (RPM) Sensor G28 for resistance.

Note. Terminal 2 is not called out in the graphic.

Specified value: 450 to 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 G28.

If specified value is obtained

1. Using Multimeter V.A.G. 1526 A or equivalent, check electrical harness connector terminals for an open circuit.

Specified value: each infinity ohms (no continuity).

If specified value was not obtained

1. Check wiring for short circuit to each other as well as to Battery positive (+) and Ground (GND).
2. If necessary, repair wiring connection.

If no malfunctions are detected in wiring

1. Replace Engine Speed (RPM) Sensor G28.

If specified value was obtained

Checking wiring connections

1. Connect Adapter Cable (121-Point) VAG1598/31 to wiring harness of Engine Control Module (ECM) J623 ; the ECM is not connected. --> «Diagnostic tester, connecting»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk) .

Scheme 1265

1. Using Adapter Cable (121-Point) VAG1598/31 and Multimeter V.A.G 1526 A or equivalent, check the following wire connections for an open circuit.

Specified value: Wire resistance max 1.5 ohms.

If specification is not obtained

1. Check wiring for a short circuit to Battery positive (+) or an open circuit.
2. If necessary, repair wiring connection.

If no malfunctions are detected

1. Replace Engine Control Module (ECM) J623 --> «Engine Control Module (ECM) J623 , replacing»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__engine-control-module-ecm-j623) .

Assembly is performed in reverse order of removal. Note the following

Final procedures

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

1. Check DTC memory..
2. If necessary, erase DTC memory..
3. If DTC memory was erased, generate readiness code..

1. End diagnosis and switch the ignition off.

Engine Coolant Temperature (ECT) Sensor G62 , checking

Special tools, testers and auxiliary items required

1. Multimeter V.A.G 1526 or equivalent.
2. Adapter Cable (121-Point) VAG1598/31.

Test requirements

1. Fuses for engine electronics OK..
2. Battery voltage at least 12.5 V.
3. Engine cold.

Checking function

1. Connect diagnostic tester. --> «Diagnostic tester, connecting»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk) .
2. Switch ignition on.
3. In diagnostic function "33 - OBD", select "Mode 1: Checking measured values".
4. Select 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.

1. Start engine and let run at idle.

Specified value: Temperature value must rise evenly.

Note. The temperature increases in increments of 10° 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.

1. End diagnosis and switch ignition off.

If the indications do not resemble description

Checking internal resistance

Scheme 1266

1. Disconnect electrical harness connector - 2 - from Engine Coolant Temperature (ECT) Sensor G62.

Scheme 1267

1. Using Multimeter V.A.G. 1526 A or equivalent, check Engine Coolant Temperature (ECT) Sensor G62 for resistance.

Specified value: 450 to 1000 ohms.

If specified value is not obtained

1. Replace Engine Coolant Temperature (ECT) Sensor G62.

If specified value is obtained

Checking voltage

1. Using Multimeter V.A.G. 1526 A or equivalent, check electrical harness connector for voltage.

1. Operate starter briefly.

Specified value: approx. Battery voltage.

1. Switch ignition off.

If specified value was obtained

1. Replace Engine Coolant Temperature (ECT) Sensor G62.

If specified value is not obtained

Checking wiring connections

1. Connect Adapter Cable (121-Point) VAG1598/31 to wiring harness of the Engine Control Module (ECM) J623 ; the ECM is not connected. --> «Diagnostic tester, connecting»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk) .

1. Using Adapter Cable (121-Point) VAG1598/31 and Multimeter V.A.G 1526 A or equivalent, check the following wiring connections for an open circuit.

Specified value: Wire resistance max 1.5 ohms.

If specification is not obtained

1. Check wiring for a short circuit to Battery positive (+) or an open circuit.
2. If necessary, repair wiring connection.

If no malfunctions are found in the wiring

1. Replace Engine Control Module (ECM) J623 --> «Engine Control Module (ECM) J623 , replacing»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__engine-control-module-ecm-j623) .

Final procedures

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

1. Check DTC memory..
2. If necessary, erase DTC memory..
3. If DTC memory was erased, generate readiness code..

1. End diagnosis and switch the ignition off.

Fuel Pump (FP) Relay J17 , checking

Special tools, testers and auxiliary items required

1. Multimeter V.A.G 1526 or equivalent.
2. Adapter Cable (121-Point) VAG1598/31.
3. Connector Test Set VAG1594C.

Note. Voltage is supplied to the Fuel Pump (FP) and several components of the fuel injection system via the Fuel Pump (FP) Relay J17. The engine must be turning for the Fuel Pump (FP) Relay J17 to close. This means that the Fuel Pump (FP) Relay J17 does not receive a Ground (GND) signal from the Engine Control Module (ECM) J623 until the Engine Control Module (ECM) J623 recognizes an RPM signal.

Test requirements

1. Battery voltage at least 12.5 V.
2. The ignition switched off.

Function test of the Fuel Pump (FP) Relay J17

Scheme 1268

1. Connect Adapter Cable (121-Point) VAG1598/31 to wiring harness of the Engine Control Module (ECM) J623 ; the ECM is not connected. --> «Diagnostic tester, connecting»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk) .
2. Remove screws - arrows - and electronics box cover from left electronics box.
3. Using Adapter Cable (121-Point) VAG1598/31 and adapter cables from connector test set V.A.G 1594 C , bridge terminals 1 and 65 together.

Scheme 1269

1. Switch ignition on.
2. The Fuel Pump (FP) Relay J17 (position 2 of the E-Box plenum chamber, left) must trigger and Fuel Pump (FP) must run.

If Fuel Pump (FP) runs

1. Check voltage supply of Fuel Pump (FP) Relay J17 --> «Check voltage supply of Fuel Pump (FP) Relay J17»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__check-voltage-supply-of-fuel-pump) .
2. Check Fuel Pump (FP) Relay J17 activation --> «Checking activation of Fuel Pump (FP) Relay J17»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__checking-activation-of-fuel-pump-fp) .

If Fuel Pump (FP) does not run

1. Check voltage supply for Fuel Pump (FP) and components (via Fuel Pump (FP) Relay J17) «Check voltage supply for Fuel Pump (FP) and components»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__check-voltage-supply-for-fuel-pump) .

Check voltage supply of Fuel Pump (FP) Relay J17

1. Remove Fuel Pump (FP) Relay J17 from position 2 of the E-Box plenum chamber, left.
2. Using Multimeter V.A.G. 1526 A or equivalent, check electrical harness connector in the E-Box plenum chamber, left for voltage.

Specified value: approx. battery voltage.

1. Using Multimeter V.A.G. 1526 A or equivalent, check electrical harness connector in the E-Box plenum chamber, left for voltage.

1. Switch ignition on.

Specified value: approx. battery voltage.

1. Switch ignition off.

If specified values are not obtained

1. Using Multimeter V.A.G. 1526 A or equivalent, check wiring connections for an open circuit

Specified value: Wire resistance max 1.5 ohms.

1. If necessary, repair wiring connection.

If no malfunctions are detected

1. Replace Engine Control Module (ECM) J623 --> «Engine Control Module (ECM) J623 , replacing»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__engine-control-module-ecm-j623) .
2. If specified values are obtained

Checking activation of Fuel Pump (FP) Relay J17

1. If installed, remove Fuel Pump (FP) Relay J17 from position 2 of the E-Box plenum chamber, left.
2. If removed, connect Adapter Cable (121-Point) VAG1598/31 to wiring harness of Engine Control Module (ECM) J623 ; the ECM is not connected. --> «Diagnostic tester, connecting»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk) .
3. Using Adapter Cable (121-Point) VAG1598/31 and Multimeter V.A.G 1526 A or equivalent, check the following wiring connection for an open circuit.

Specified value: Wire resistance max 1.5 ohms.

If specification is not obtained

1. Check wiring for a short circuit to Battery positive (+) or an open circuit.
2. If necessary, repair wiring connection.

If no malfunctions are detected

1. Replace Fuel Pump (FP) Relay J17.

Check voltage supply for Fuel Pump (FP) and components

1. Remove fuses SA14, SA15, SA16, SA17, and SC1 from fuse holders.
2. Using Multimeter V.A.G. 1526 A or equivalent, check fuses for voltage.
3. Operate starter briefly.

If specification is not obtained

1. Check the wiring for a short circuit to Battery positive (+) or an open circuit.
2. If necessary, repair wiring connection.

If no malfunctions are detected

1. Replace Fuel Pump (FP) Relay J17.
2. Reinstall fuses.

Final procedures

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

1. Check DTC memory..
2. If necessary, erase DTC memory..
3. If DTC memory was erased, generate readiness code..

1. End diagnosis and switch the ignition off.

Fuel pressure regulator and holding pressure, checking

Note. The fuel pressure regulator is located in the fuel filter under the fuel tank.

Special tools, testers and auxiliary items required

Scheme 1270

1. Fuel injection pressure gauge V.A.G 1318 with V.A.G 1318/6 and V.A.G 1318/7

Test conditions

1. Fuel Pump (FP) Relay OK. --> «Fuel Pump (FP) Relay J17 , checking»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__fuel-pump-fp-relay-j17) .
2. Fuel Pump (FP) OK.
3. Fuel filter OK.
4. Battery voltage at least 12.5 Volts.

1. Automatic transmission selector lever in position "P" or "N".

1. Briefly open fuel filler cap to relieve pressure.

1. Remove rear engine cover - arrows -.

1. Remove resonator - 1 - in direction of - arrow - from air duct hose.

1. Open threaded connection - arrow - and catch any escaping fuel using a shop rag.
2. Install Fuel injection pressure gauge V.A.G 1318 between fuel supply line and fuel rail.

Note. The shut-off valve of the fuel injection pressure gauge V.A.G 1318 must be installed on the tank-side (fuel supply line)!

1. Open shut-off valve of pressure gauge. The lever points in direction of flow.
2. Start engine and run at idle speed.
3. Measure fuel pressure.

Specification: approx. 4 bar positive pressure.

1. Switch ignition off.
2. Check for leaks and for holding pressure by observing the pressure loss on pressure gauge.

After 10 minutes there must be a residual pressure of at least 2.5 bar.

The holding pressure drops below 2.5 bar

1. Start engine and let run at idle speed.

Scheme 1271

1. Wait until pressure has risen, and then switch off ignition. Simultaneously close shut-off valve of fuel injection pressure gauge V.A.G 1318 (lever perpendicular to direction of flow).
2. Watch pressure drop on gauge.

If pressure drops again

1. Check for leaks in threaded connection between pressure gauge and fuel supply line.
2. Check pressure gauge for leaks.
3. Check line connections, O-rings at fuel rail and fuel injectors for leaks.

If pressure does not drop

1. Replace fuel filter. --> «20 - FUEL SUPPLY»(/audi/a6/6-2004-2008/remont/fuel-system/#fuel-supply-system) .
2. Test check-valve of Fuel Pump (FP) --> «20 - FUEL SUPPLY»(/audi/a6/6-2004-2008/remont/fuel-system/#fuel-supply-system) .

Fuel Injectors , checking

The following procedure is used to check all fuel injectors.

Special tools, testers and auxiliary items required

1. Multimeter V.A.G 1526 A or equivalent.
2. Adapter Cable (121-Point) VAG1598/31.
3. Voltage Tester VAG1527B or equivalent.
4. Connector Test Set VAG1594C

Test requirements

1. The fuses for engine electronics OK..
2. Fuel Pump (FP) Relay OK. --> «Fuel Pump (FP) Relay J17 , checking»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__fuel-pump-fp-relay-j17) .
3. The parking brake engaged.
4. The battery voltage at least 12.5 V.

1. The selector lever of automatic transmission in position "P" or "N".
2. All electrical consumers switched off (radiator fan must NOT run during test).
3. A/C switched off.
4. Fuel tank at least 1 / 4 filled.

1. Ignition switched off.

Procedure

1. Remove front engine cover - arrows -1- and -2 -.

1. Remove rear engine cover - arrows -.

1. Remove resonator - 1 - in direction of - arrow - from air duct hose.

Scheme 1272

1. Disconnect fuel injector electrical harnesses - 1 - and - 5 - from fuel injectors.

Scheme 1273

Checking internal resistance

1. Using Multimeter V.A.G 1526 A or equivalent, check fuel injectors for resistance.

Specified value: 12 to 13 ohms (at room temperature).

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

If specified value is not obtained

1. Replace faulty fuel injector --> «Fuel injectors, removing and installing»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__fuel-injectors-removing-and-installing) .

If specified value is obtained

Scheme 1274

Checking voltage supply

1. Using Voltage Tester VAG1527B or equivalent, check terminal 1 of the fuel injector for voltage.
2. Operate starter briefly.

LED must light up.

1. Switch ignition off.

If LED does not light up

1. Using Multimeter V.A.G 1526 A or equivalent, check wiring from fuel injector electrical connector to Fuel Pump (FP) Relay J17 terminal via fuse for an open circuit.

Specified value: Wire resistance max 1.5 ohms.

If specification is not obtained

1. Check wiring for a short circuit to Battery positive (+) or an open circuit.
2. If necessary, repair wiring connection.

If no malfunctions are found in wiring

Checking activation

1. Connect electrical connector to fuel injector.
2. Slide plastic grommet off of fuel injector electrical connector, leaving electrical connector connected to fuel injector.
3. Using Voltage Tester VAG1527B or equivalent and a probe from Connector Test Set VAG1594C , check electrical harness connector for voltage.
4. Operate starter briefly.

The 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.

1. Switch ignition off.

If LED does not blink

1. Connect Adapter Cable (121-Point) VAG1598/31 to wiring harness of Engine Control Module (ECM) J623 ; the ECM is not connected. --> «Diagnostic tester, connecting»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk) .
2. Using Adapter Cable (121-Point) VAG1598/31 and Multimeter V.A.G 1526 A or equivalent, check the following wiring connections for an open circuit.

Specified value: Wire resistance max 1.5 ohms.

If specification is not obtained

1. Check wiring for a short circuit to Battery positive (+) or an open circuit.
2. If necessary, repair wiring connection.

If no malfunctions are detected

1. Replace Engine Control Module (ECM) J623 --> «Engine Control Module (ECM) J623 , replacing»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__engine-control-module-ecm-j623) .

Assembly is performed in reverse order of removal. Note the following

Final procedures

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

1. Check DTC memory..
2. If necessary, erase DTC memory..
3. If DTC memory was erased, generate readiness code..

1. End diagnosis and switch ignition off.

Injection quantity, leak check, and spray pattern of fuel injectors

Special tools, testers and auxiliary items required

1. Connector test set V.A.G 1594 C or equivalent.
2. Adapter Cable (121-Point) VAG1598/31.
3. Fuel injection quantity tester V.A.G 1602.
4. Remote control for VAG 1348 V.A.G 1348/3 A.

1. Adapter cable V.A.G 1348/3 - 2.

Test conditions

1. Fuel pressure OK.

Checking fuel injectors for leaks

1. Remove front engine cover - arrows -1- and -2 -.

1. Remove rear engine cover - arrows -.

1. Remove resonator - 1 - in direction of - arrow - from air duct hose.
2. Disconnect electrical connectors from fuel injectors.

Remove bolts - arrows - securing fuel rail to intake manifold.

1. Remove fuel rail with fuel injectors attached, from intake manifold - arrows -.

Scheme 1275

1. Insert the fuel injector to be tested into the measuring container of the fuel injection quantity tester V.A.G 1602.
2. Connect Adapter Cable (121-Point) VAG1598/31 to wiring harness of Engine Control Module (ECM) J623 ; the ECM is not connected. --> «Diagnostic tester, connecting»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk) .
3. Using Adapter Cable (121-Point) VAG1598/31 and adapter cables from connector test set V.A.G 1594 C , bridge terminals 1 and 65 together.
4. Switch ignition on.

Note. After switching the ignition on, the Fuel Pump (FP) will run continuously. After switching the ignition on, the Fuel Pump (FP) relay supplies continuous battery positive (B+) via central electronics. Ground (GND) is supplied to the FP relay via the bridge in the test box.

1. Check fuel injector for leaks (visual check). Only 1 to 2 drops per minute may emit from each valve when fuel pump is running.

Switch ignition off.

If fuel loss is greater than specified

1. Replace faulty fuel injector. --> «Fuel injectors, removing and installing»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__fuel-injectors-removing-and-installing) .

Injection quantity, checking

Note. When checking the injection quantity, the spray pattern should also be checked. Spray pattern must be the same for all fuel injectors.

1. Insert fuel injector to be tested into measuring container of fuel injection quantity tester V.A.G 1602.
2. Connect one terminal of the fuel injector to engine Ground (GND) using an adapter cable and an alligator clip from the connector test set V.A.G 1594 C.

Scheme 1276

1. Connect the second terminal of the fuel injector to Battery Positive (B+) with the remote control for VAG 1348 V.A.G 1348/3 A and adapter cable V.A.G 1348/3 - 2.
2. Using Adapter Cable (121-Point) VAG1598/31 and adapter cables from connector test set V.A.G 1594 C , bridge terminals 1 and 65 together.
3. Switch ignition on. (the Fuel Pump must run).
4. Using remote control for VAG 1348 V.A.G 1348/3 A , operate each fuel injector for 30 seconds to perform fuel injector measurement.

1. After all 4 fuel injectors have been activated, place measuring containers on a level surface.

Specified value per fuel injector: 105 to 125 ml.

If specified value is not obtained for all fuel injectors

1. Check fuel pressure --> «Fuel pressure regulator and holding pressure, checking»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__fuel-pressure-regulator-and-holding-pressure) .

If specified value is not obtained for only one fuel injector

1. Replace faulty fuel injector. --> «Fuel injectors, removing and installing»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__fuel-injectors-removing-and-installing) .

Installing

1. Installation is in reverse order of removal. Note the following

1. Replace all O-rings at all opened connections. (Never remove plastic cap from valve head to replace front O-ring, lift the O-ring off over plastic cap).
2. Lightly lubricate new O-rings with clean engine oil.
3. Make sure fuel injectors are in place and seated correctly.
4. Check clip for unobstructed fitting.

1. Place fuel rail with secured fuel injectors onto intake manifold, and apply uniform pressure to seat it in the intake manifold.

Tightening torque

Intake system for leaks (false air), checking

Special tools, testers and auxiliary items required

1. Engine Leak Detection Spray G 001 800 A1.
2. Engine leak detection spray G 001 800 A1.

Note. Vacuum in the intake system sucks in the leak detection spray with 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.

Test requirements

1. Coolant temperature at least 80C°.
2. The parking brake engaged.
3. The selector lever of automatic transmission in position "P" or "N".
4. The ignition switched off.

Test sequence

1. Connect diagnostic tester. --> «Diagnostic tester, connecting»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk) .
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

1. Spray intake system parts with engine leak detection spray in a systematic manner.

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

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

Final procedures

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

1. Check DTC memory..
2. If necessary, erase DTC memory..
3. If DTC memory was erased, generate readiness code..

1. End diagnosis and switch ignition off.

Heated Oxygen Sensor (HO2S) before catalytic converter, checking

This procedure is used to check Heated Oxygen Sensor (HO2S) G39 and Heated Oxygen Sensor (HO2S) 2 G108

Special tools, testers and auxiliary items required

1. Multimeter V.A.G 1526 or equivalent.
2. Adapter Cable (121-Point) VAG1598/31.

Test requirements

1. The fuses for the engine electronics OK..
2. Fuel Pump (FP) Relay OK. --> «Fuel Pump (FP) Relay J17 , checking»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__fuel-pump-fp-relay-j17) .
3. Battery voltage at least 12.5 V.
4. The Ground (GND) connections at engine and transmission OK.

1. The Oxygen sensor heater OK --> «Oxygen Sensor (O2S) Heater for Heated Oxygen Sensor (HO2S) before catalytic converter, checking»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__oxygen-sensor-o2s-heater-for-heated) .
2. The exhaust system free of leaks. --> «Exhaust system, checking for proper seal»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__exhaust-system-checking-for-proper-seal) .
3. The parking brake engaged.
4. The selector lever of automatic transmission in position "P" or "N".

1. All electrical consumers switched off (radiator fan must NOT run during test).
2. The A/C switched off.
3. The coolant temperature at least 80° C.

Procedure

Note. Bank 1 = cylinder bank 1 in direction of travel, right; Bank 2 = cylinder bank 2 in direction of travel, left. When selecting the diagnostic mode, the entry is always performed in "Bank 1 sensor 1". When servicing terminals in harness connector of oxygen sensor, use only gold-plated terminals.

Checking Heated Oxygen Sensor (HO2S) -G39- and Heated Oxygen Sensor (HO2S) -G108- wiring.

1. Disconnect 6-pin electrical harness connector - 1 - from Heated Oxygen Sensor (HO2S) -G39- (bank 1, sensor 1).

To test Heated Oxygen Sensor (HO2S) -G108- (bank 2, sensor 1), perform the following steps

1. Remove screw - arrow - retaining coolant reservoir.

1. Disconnect electrical connector from Engine Coolant Level (ECL) Warning Switch F66 at the bottom of the coolant reservoir and set aside the coolant reservoir with the coolant hoses - 1 - and - 2 - connected.
2. Disconnect 6-pin electrical harness connector - 1 - from Heated Oxygen Sensor (HO2S) -G108-.

1. Connect Adapter Cable (121-Point) VAG1598/31 to wiring harness of Engine Control Module (ECM) J623 ; the ECM is not connected. --> «Diagnostic tester, connecting»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk) .
2. Using the Adapter Cable (121-Point) VAG1598/31 and Multimeter V.A.G 1526 A or equivalent, check the following wire connection for an open circuit.

1. Heated Oxygen Sensor (HO2S) -G39- (Bank 1, Sensor 1).

1. Heated Oxygen Sensor (HO2S) -G108- (Bank 2, Sensor 1).

Specified value: Wire resistance max 1.5 ohms.

If specification is not obtained

1. Check wiring for a short circuit to Battery positive (+) or an open circuit.
2. If necessary, repair wiring connection.

If no malfunctions are found in wiring

1. Replace Heated Oxygen Sensor (HO2S) -G39- --> «Heated oxygen sensor (HO2S) G39 before catalytic converter, bank 1 (right), removing and installing»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk) or Heated Oxygen Sensor (HO2S) -G108- --> «Heated oxygen sensor (HO2S) 2 G108 before catalytic converter, bank 2 (left), removing and installing»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__heated-oxygen-sensor-ho2s-2-g108) .

Final procedures

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

1. Check DTC memory..
2. If necessary, erase DTC memory..
3. If DTC memory was erased, generate readiness code..

1. End diagnosis and switch ignition off.

Heated Oxygen Sensor (HO2S) behind catalytic converter, checking

This procedure is used to check Oxygen Sensor (O2S) Behind Three Way Catalytic Converter (TWC) G130 and Oxygen Sensor (O2S) 2 Behind Three Way Catalytic Converter (TWC) G131

Note. The oxygen sensor before catalytic converter (bank 1, sensor 1 or bank 2, 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 or bank 2, sensor 2). If it recognizes the deviations downward or upward, it influences the regulation before catalytic converter, generally increasing or decreasing it respectively.

Special tools, testers and auxiliary items required

1. Multimeter V.A.G 1526 or equivalent.
2. Adapter Cable (121-Point) VAG1598/31.

Test requirements

1. The fuses for engine electronics OK..
2. Fuel Pump (FP) Relay OK. --> «Fuel Pump (FP) Relay J17 , checking»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__fuel-pump-fp-relay-j17) .
3. Battery voltage at least 12.5 V.
4. The Ground (GND) connections at engine and transmission OK.

1. The Oxygen sensor heater OK --> «Oxygen Sensor (O2S) Heater for Oxygen Sensor (O2S) Behind Three Way Catalytic Converter (TWC) , checking»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__oxygen-sensor-o2s-heater-for-oxygen) .
2. The exhaust system free of leaks. --> «Exhaust system, checking for proper seal»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__exhaust-system-checking-for-proper-seal) .
3. The parking brake engaged.
4. The selector lever of automatic transmission in position "P" or "N".

1. All electrical consumers switched off (radiator fan must NOT run during test).
2. The A/C switched off.
3. The coolant temperature at least 80° C.

Procedure

Note. Bank 1 = cylinder bank 1 in direction of travel, right; Bank 2 = cylinder bank 2 in direction of travel, left. When servicing terminals in harness connector of oxygen sensor, use only gold-plated terminals.

Checking primary voltage

1. Disconnect 4-pin electrical harness connector - 3 - from Heated Oxygen Sensor (HO2S) -G130- (bank 1, sensor 2).

To test Heated Oxygen Sensor (HO2S) -G131- (bank 2, sensor 2), perform the following steps

1. Remove screw - arrow - retaining coolant reservoir.

1. Disconnect electrical connector from Engine Coolant Level (ECL) Warning Switch F66 at the bottom of the coolant reservoir and set aside coolant reservoir with the coolant hoses - 1 - and - 2 - connected.

1. Disconnect 4-pin electrical harness connector - 4 - from Heated Oxygen Sensor (HO2S) -G131-.
2. Using Multimeter V.A.G 1526 A or equivalent, check electrical harness connector terminals 3 to 4 for voltage.
3. Switch ignition on.

Specified value: 0.400 to 0.500 V.

1. Switch ignition off.

If specified value is not obtained

1. Replace Oxygen Sensor (O2S) Behind Three Way Catalytic Converter (TWC) G130 --> «Oxygen sensor (O2S) behind three way catalytic converter (TWC) G130 , bank 1 (right), removing and installing»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__oxygen-sensor-o2s-behind-three-way) or Oxygen Sensor (O2S) 2 Behind Three Way Catalytic Converter (TWC) G131 --> «Oxygen Sensor (O2S) 2 Behind Three Way Catalytic Converter (TWC) G131 after catalytic converter, bank 2 (left), removing and installing»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__oxygen-sensor-o2s-2-behind-three) .

If specified value is obtained

Checking wiring

1. Connect Adapter Cable (121-Point) VAG1598/31 to wiring harness of the Engine Control Module (ECM) J623 ; the ECM is not connected. --> «Diagnostic tester, connecting»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk) .
2. Using Adapter Cable (121-Point) VAG1598/31 and Multimeter V.A.G 1526 A or equivalent, check the following wire connection for an open circuit.

1. Oxygen Sensor (O2S) Behind Three Way Catalytic Converter (TWC) G130

1. Oxygen Sensor (O2S) Behind Three Way Catalytic Converter (TWC) G131

Specified value: Wire resistance max 1.5 ohms.

If specification is not obtained

1. Check wiring for a short circuit to Battery positive (+) or an open circuit.
2. If necessary, repair wiring connection.

If no malfunctions are found in the wiring

1. Replace Engine Control Module (ECM) J623 --> «Engine Control Module (ECM) J623 , replacing»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__engine-control-module-ecm-j623) .

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

1. Check DTC memory..
2. If necessary, erase DTC memory..
3. If DTC memory was erased, generate readiness code..

1. End diagnosis and switch ignition off.

Engine Control Module (ECM) J623 voltage supply, checking

Special tools, testers and auxiliary items required

1. Multimeter V.A.G 1526 A or equivalent.
2. Adapter Cable (121-Point) VAG1598/31.

Test requirements

1. Fuse for engine electronics OK.
2. Ground (GND) connections at engine and transmission OK.
3. Battery voltage at least 12 V.
4. Generator OK.

1. Ignition is switched off.

Test sequence

1. Connect Adapter Cable (121-Point) VAG1598/31 to wiring harness of the Engine Control Module (ECM) J623 ; the ECM is not connected. --> «Diagnostic tester, connecting»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk) .
2. Switch ignition on.
3. Using Adapter Cable (121-Point) VAG1598/31 and Multimeter V.A.G 1526 A or equivalent, check the following wiring connections for voltage.

Specified value: approx. battery voltage.

1. Switch ignition off.
2. Using Multimeter V.A.G. 1526 A or equivalent, check the following wiring connections for voltage.

1. Switch ignition on.

Specified value: approx. battery voltage.

1. Switch ignition off.

If specified values are not obtained

1. Using Multimeter V.A.G. 1526 A or equivalent, check wiring connections for an open circuit.

Specified value: Wire resistance max 1.5 ohms.

1. If necessary, repair wiring connection.

If no malfunctions are found in the wiring

1. Check Motronic Engine Control Module (ECM) Power Supply Relay J271 --> «Motronic Engine Control Module (ECM) Power Supply Relay J271 , checking»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__motronic-engine-control-module-ecm-power) .

Final procedures

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

1. Check DTC memory.
2. If necessary, erase DTC memory.
3. If DTC memory was erased, generate readiness code.

1. End diagnosis and switch ignition off.

Motronic Engine Control Module (ECM) Power Supply Relay J271 , checking

Special tools, testers and auxiliary items required

1. Multimeter V.A.G 1526 A or equivalent.
2. Adapter Cable (121-Point) VAG1598/31.

Note. The Motronic Engine Control Module (ECM) Power Supply Relay J271 supplies voltage to the ignition coils with power output stages as well as the Engine Control Module (ECM) J623 at pin 3 and a few additional components. With the ignition switched on, 12 Volts must be present at the respective ignition coil connector, terminal 1.

Test requirement

1. The fuse for engine electronics OK..
2. Battery voltage at least 12.5 V.
3. The Ground (GND) connections at engine and transmission OK.
4. The ignition is switched off.

Test sequence

Scheme 1277

1. Remove rubber seal - 1 - from plenum chamber cover.
2. Remove plenum chamber cover - 2 -.

Scheme 1278

1. Using a screwdriver, remove wiper arms caps - arrows -.
2. Loosen wiper arm nuts - arrows - several turns.
3. Loosen wiper arms by gently rocking.

Scheme 1279

1. Remove wiper arm nuts and wiper arms.
2. Remove screws - arrows - retaining cowl grill - 1 -.

1. Remove cowl grill from windshield.
2. Remove screws - arrows - and electronics box cover from electronics box.

1. Remove Motronic Engine Control Module (ECM) Power Supply Relay J271 from position 3 of the E-Box plenum chamber, left.

Scheme 1280

1. Connect Adapter Cable (121-Point) VAG1598/31 to wiring harness of the Engine Control Module (ECM) J623 ; the ECM is not connected. --> «Diagnostic tester, connecting»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk) .
2. Using Adapter Cable (121-Point) VAG1598/31 and Multimeter V.A.G 1526 A or equivalent, check the following wiring connection for an open circuit.

Specified value: Wire resistance max 1.5 ohms.

If specification is not obtained

1. Check wiring for a short circuit to Battery positive (+) or an open circuit.
2. If necessary, repair wiring connection.

If no malfunctions are found in the wiring

Checking voltage supply

1. Using Multimeter V.A.G 1526 A or equivalent, check the following wiring connections for voltage.

Specified value: approx. battery voltage.

If specified value is not obtained

1. Using Multimeter V.A.G 1526 A or equivalent, check wiring connections for an open circuit.

Specified value: Wire resistance max 1.5 ohms.

If no malfunctions are found in the wiring

Checking wire connection

1. Using Adapter Cable (121-Point) VAG1598/31 and Multimeter V.A.G 1526 A or equivalent, check the following wiring connection for an open circuit.

Specified value: Wire resistance max 1.5 ohms.

If specification is not obtained

1. Check wiring for a short circuit to Battery positive (+) or an open circuit.
2. If necessary, repair wiring connection.

If no malfunctions are detected

1. Replace Engine Control Module (ECM) J623 --> «Engine Control Module (ECM) J623 , replacing»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__engine-control-module-ecm-j623) .

Assembly is performed in reverse order of removal. Note the following

Final procedures

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

1. Check DTC memory..
2. If necessary, erase DTC memory..
3. If DTC memory was erased, generate readiness code..

1. End diagnosis and switch ignition off.

Engine Control Module (ECM) J623 , removing and installing

Special tools, testers and auxiliary items required

Scheme 1281

1. Hot air gun VAS 1978/14 - Pos. 1 - with nozzle attachment - 2 - from wiring harness repair kit VAS 1978 or equivalent.
2. Locking pliers - 3 - (commercially available).

Removing

1. Remove rubber seal - 1 - from plenum chamber cover.

1. Remove plenum chamber cover - 2 -.
2. Using a screwdriver, remove wiper arms caps - arrows -.
3. Loosen wiper arm nuts - arrows - several turns.
4. Loosen wiper arms by gently rocking.

1. Remove wiper arm nuts and wiper arms.
2. Remove screws - arrows - retaining the cowl grill - 1 -.
3. Remove cowl grill from windshield.

Scheme 1282

1. Remove screws - arrows - and electronics box cover from the electronics box.

Scheme 1283

1. Using a screwdriver - arrows 1 and 2 - , carefully remove the retaining clip - 2 -.

Scheme 1284

1. Using Hot air gun VAS 1978/14 heat the shear bolts as follows
2. Direct heat gun nozzle at shear bolts of the protective housing.

Scheme 1285

1. Switch heat gun on and heat bolt for approx. 20 to 25 seconds.
2. Remove shear bolts with locking pliers - arrow -.

Scheme 1286

Note. When the electrical connector is disconnected from the Engine Control Module (ECM) J623 , adaptation values are erased and content of the DTC memory remains intact.

1. Remove electrical harness connector retaining brackets and electrical harness connectors from Engine Control Module (ECM) J623.
2. Remove Engine Control Module (ECM) J623.

Installing

Installation is performed in reverse order of removal. Note the following

Note. New shear bolts must be used when reinstalling the electrical harness connector retaining brackets to the Engine Control Module (ECM) J623. After installing a new Engine Control Module (ECM) J623 it must be adapted. --> Engine Control Module (ECM) J623 , replacing .

Final procedures

After connecting electrical harness connectors to Engine Control Module (ECM) J623 , the following work steps must be performed in the following sequence

1. Check DTC memory..
2. If necessary, erase DTC memory..
3. If DTC memory was erased, generate readiness code..

Engine Control Module (ECM) J623 , replacing

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) J623. So that this system cannot be circumvented, it is necessary to perform adaptation of the anti-theft immobilizer using the Vehicle Diagnosis Service Syst. VAS5052 in the On Board Diagnostic (OBD) function. The great availability of equipment options makes adaptation of the Engine Control Module (ECM) J623 necessary (e.g. cruise control system). This "writing" function is not possible with the generic scan tool, therefore it is necessary to use the Vehicle Diagnosis Service Syst. VAS5052 in On Board Diagnostic (OBD) function for this purpose. If the Engine Control Module (ECM) J623 must be replaced, the vehicle may be taken to the nearest Audi dealership for instructions on obtaining a Vehicle Diagnosis Service Syst. VAS5052.

Work procedure

1. Connect Vehicle Diagnosis Service Syst. VAS5052. --> «Diagnostic tester, connecting»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk) .
2. Activate engine control module via "Guided fault finding" function (diagnosis object "Replacing engine control module").

Final procedures

After activation of the Engine Control Module (ECM) J623 , the following work steps must be performed in the following sequence

1. Check DTC memory..
2. If necessary, erase DTC memory..
3. If DTC memory was erased, generate readiness code..

Speed signal, checking

Test requirement

1. Function and display of speedometer OK.

1. Connect diagnostic tester. --> «Diagnostic tester, connecting»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk) .
2. Start engine and let run at idle.
3. In the diagnostic function "33 - OBD", select "Diagnostic mode 1: Obtain data".
4. Select measured value "PID 13: Vehicle speed".

1. Perform a road test, and have the 2nd person observe the indication on the display.
2. Check specified value of the vehicle speed

1. End diagnosis and switch ignition off.

If no speed is displayed

The speed signal is transferred from Engine Control Module (ECM) J623 to instrument cluster via wire connection or via CAN-Bus, depending on version.

1. Check wiring connections.
2. Check terminal resistance for CAN-Bus --> «Terminal resistance for Can-Bus, checking»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__terminal-resistance-for-can-bus-checking) .

Final procedures

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

1. Check DTC memory..
2. If necessary, erase DTC memory..
3. If DTC memory was erased, generate readiness code..

1. End diagnosis and switch ignition off.

Terminal resistance for Can-Bus, checking

The Engine Control Module (ECM) J623 communicates with all the databus capable control modules via a CAN databus.

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 databus is recognized as a malfunction and stored.

Trouble-free operation of the CAN-bus requires that it have a terminal resistance. The central terminal resistor is located in the Engine Control Module (ECM) J623.

Special tools, testers and auxiliary items required

1. Multimeter V.A.G 1526 or equivalent.
2. Adapter Cable (121-Point) VAG1598/31.

Test requirement

1. Ignition switched off.

Test sequence

1. Connect Adapter Cable (121-Point) VAG1598/31 to wiring harness of the Engine Control Module (ECM) J623 ; the wiring harness is not connected. --> «Diagnostic tester, connecting»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk) .
2. Check the central termination resistor in the Engine Control Module (ECM) J623.
3. Using Multimeter V.A.G 1526 A or equivalent, check the following wiring connection between terminal 58 and 60 of the Test box V.A.G. 1598/31 for resistance.

Specified value: 60 to 72 ohms

If specification is exceeded or not met

1. Replace Engine Control Module (ECM) J623 --> «Engine Control Module (ECM) J623 , replacing»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__engine-control-module-ecm-j623) .

If specified value is obtained

1. Disconnect Adapter Cable (121-Point) VAG1598/31 from Engine Control Module (ECM) J623 wiring harness.
2. Connect Adapter Cable (121-Point) VAG1598/31 to wiring harness of the Engine Control Module (ECM) J623 ; the ECM is not connected --> «Diagnostic tester, connecting»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk) .
3. Using Multimeter V.A.G 1526 A or equivalent, check the following wiring connection between terminal 58 and 60 of the Test box V.A.G. 1598/31 for resistance.

Specified value: Wire resistance max 1.5 ohms

If specification is not obtained

1. Check wiring for a short circuit to Battery positive (+) or an open circuit.
2. If necessary, repair wiring connection.

Final procedures

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

1. Check DTC memory..
2. If necessary, erase DTC memory..
3. If DTC memory was erased, generate readiness code..

1. End diagnosis and switch ignition off.

Exhaust system components, removing and installing

Note. Replace all gaskets and self-locking nuts. After exhaust system repairs, make sure the exhaust system is not under stress and is far enough from the body. If necessary, loosen clamping sleeves and align the mufflers and exhaust pipes so that there is adequate distance to the vehicle body and weight is evenly distributed among the exhaust hangers. The flex joint in the front exhaust pipe must not be bent more than 10° , otherwise it may be damaged.

Scheme 1287

1 - 23 Nm

2 - Mount

1. Replace if damaged.

3 - Center muffler

1. Original equipment as one unit with rear muffler. For repairs, replace each separately.
2. Install exhaust system free of stress --> «Exhaust system, installing free of tension»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__exhaust-system-installing-free-of-tension) .

4 - Exhaust manifold

5 - Gasket

1. Replace

6 - 23 Nm

1. Replace

7 - Front exhaust pipe with catalytic converter and front muffler

1. For cylinder bank 2 (left).
2. With decoupling element; decoupling element must not be bent more than 10° otherwise it may be damaged.
3. Protect from shocks and impact stress.
4. Removing and installing --> «Left exhaust pipe with catalytic converter, removing and installing»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__left-exhaust-pipe-with-catalytic-converter) .

1. Individual mounting components «Individual components of suspension, left side»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk)
2. Install exhaust system free of stress --> «Exhaust system, installing free of tension»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__exhaust-system-installing-free-of-tension) .

8 - Oxygen Sensor (O2S) Behind Three Way Catalytic Converter (TWC)

1. Threads of new oxygen sensors are coated with assembly paste; paste must not get into slots of oxygen sensor body
2. When re-using old oxygen sensor, grease threads with hot bolt paste; paste must not get into slots of oxygen sensor body; hot bolt paste .
3. Removing and installing Oxygen sensor (O2S) behind three way catalytic converter (TWC) G130 --> «Oxygen sensor (O2S) behind three way catalytic converter (TWC) G130 , bank 1 (right), removing and installing»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__oxygen-sensor-o2s-behind-three-way) .
4. Removing and installing Oxygen Sensor (O2S) 2 Behind Three Way Catalytic Converter (TWC) G131 --> «Oxygen Sensor (O2S) 2 Behind Three Way Catalytic Converter (TWC) G131 after catalytic converter, bank 2 (left), removing and installing»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__oxygen-sensor-o2s-2-behind-three) .

1. Fasten to 55 Nm.

9 - Front clamping sleeves

1. Installed location «Installed position of front clamping sleeves»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk)
2. Before tightening, align exhaust system so that it is tension-free --> «Exhaust system, installing free of tension»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__exhaust-system-installing-free-of-tension) .
3. Tighten threaded connections evenly.

10 - 23 Nm

11 - Front exhaust pipe with catalytic converter and front muffler

1. For cylinder bank 1 (right).
2. With decoupling element; decoupling element must not be bent more than 10° otherwise it may be damaged.
3. Protect from shocks and impact stress.
4. Removing and installing --> «Right exhaust pipe with catalytic converter, removing and installing»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__right-exhaust-pipe-with-catalytic-converter) .

1. Individual mounting components «Individual components of suspension, right side»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk)
2. Install exhaust system free of stress --> «Exhaust system, installing free of tension»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__exhaust-system-installing-free-of-tension) .

12 - Rear muffler

1. Left side of vehicle
2. Original equipment as one unit with center muffler. For repairs, replace each separately.
3. Separating point
4. Install exhaust system free of stress --> «Exhaust system, installing free of tension»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__exhaust-system-installing-free-of-tension) .

13 - 23 Nm

1. Replace

14 - Mount

15 - 23 Nm

16 - Mount

1. Replace if damaged

17 - Rear muffler

1. Right side of vehicle.
2. Original equipment as one unit with center muffler. For repairs, replace each separately.
3. Separating point
4. Install exhaust system free of stress --> «Exhaust system, installing free of tension»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__exhaust-system-installing-free-of-tension) .

18 - Bracket

19 - 23 Nm

20 - Rear clamping sleeves

1. For individual replacement of center and rear mufflers.
2. Position clamping sleeve centrally to separation point.
3. Installed location «Installed position of rear clamping sleeves»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk)
4. Before tightening, align exhaust system so that it is tension-free --> «Exhaust system, installing free of tension»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__exhaust-system-installing-free-of-tension) .

1. Tighten threaded connections evenly.

Scheme 1288

1. Install clamping sleeves so that bolt ends do not project over lower edge of sleeve.

1. Threaded connections point toward right side.

Scheme 1289

1. Install clamping sleeves so that bolt ends do not project over lower edge of sleeves.

1. Threaded connections point toward outside.

Scheme 1290

1. Bolt
2. Washer
3. Spring
4. Spacing sleeve
5. Nut, 23 Nm
6. Spacing sleeve
7. Tongue
8. Buffer
9. Spacing sleeve
10. Bolt, 23 Nm

Scheme 1291

1. Nut, 23 Nm
2. Spacing sleeve
3. Tongue
4. Buffer
5. Spacing sleeve
6. Bolt, 23 Nm
7. Bolt
8. Washer
9. Spring
10. Spacing sleeve

Scheme 1292

1. 23 Nm
2. Bracket
3. 23 Nm
4. 23 Nm

Scheme 1293

Special tools, testers and auxiliary items required

1. Ring spanner 7-piece set 3337 for oxygen sensor.

Note. All cable ties which are loosened or cut open when removing, must be replaced in the same position when installing. Remove rear engine cover - arrows -.

1. Remove MAF sensor with air duct hose between air filter and throttle valve control module J338.

1. Disconnect electrical connector - 1 -.

Scheme 1294

1. Expose oxygen sensor wire up to oxygen sensor.
2. Remove Heated oxygen sensor (HO2S) G39 from between engine and bulkhead, using tool from ring spanner set 3337.

Note. Shown in illustration with engine removed.

Installing

Installation is performed in reverse order of removal. Note the following

Note. New oxygen sensor threads are coated with an assembly paste. This paste must not contact sensor openings. For a used oxygen sensor, only grease threads with high-temperature lubricant. This paste must not contact sensor openings; High-temperature lubricant . During installation, all cable ties must be re-installed at the same location to prevent the oxygen sensor wiring from contacting the exhaust manifold.

Tightening torque

Heated oxygen sensor (HO2S) 2 G108 before catalytic converter, bank 2 (left), removing and installing

Special tools, testers and auxiliary items required

1. Ring spanner 7-piece set 3337 for oxygen sensor.

Removing

Note. All cable ties which are opened or cut open when removing must be replaced in the same position when installing. Remove rear engine cover - arrows -.

Scheme 1295

1. Remove coolant expansion tank - arrow -.

1. Disconnect electrical connector from Engine Coolant Level (ECL) Warning Switch -F66- at bottom of coolant reservoir and set aside coolant reservoir with coolant hoses - 1 - and - 2 - connected.
2. Disconnect electrical connector - 1 -.
3. Remove retainer for the 4 electrical connections on bulkhead (to simplify removal and installation of oxygen sensor).

Scheme 1296

1. Expose oxygen sensor wire up to oxygen sensor.
2. Remove Heated oxygen sensor (HO2S) 2 G108 from between engine and bulkhead, using tool from ring spanner set 3337.

Note. Shown in illustration with engine removed.

Installing

Installation is performed in reverse order of removal. Note the following

Note. New oxygen sensor threads are coated with an assembly paste. This paste must not contact sensor openings. For a used oxygen sensor, only grease threads with high-temperature lubricant. This paste must not contact sensor openings; High-temperature lubricant During installation, all cable ties must be re-installed at the same location to prevent the oxygen sensor wiring from contacting the exhaust manifold. Secure all hose connections using hose clamps appropriate for model type .

Tightening torque

Oxygen sensor (O2S) behind three way catalytic converter (TWC) G130 , bank 1 (right), removing and installing

Special tools, testers and auxiliary items required

1. Ring spanner 7-piece set 3337 for oxygen sensor.

Removing

Note. All cable ties which are loosened or cut open when removing, must be replaced in the same position when installing.

Remove rear engine cover - arrows -.

1. Remove air duct hose with Mass Air Flow (MAF) Sensor G70 and set it aside.

1. Disconnect electrical connector - 3 -.
2. Expose oxygen sensor wire up to oxygen sensor.
3. Remove sound insulation.
4. Remove right front exhaust pipe --> «26 - EXHAUST SYSTEM, EMISSION CONTROLS»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-engine-mechanical-engine-codes-bat-bnk) .

1. Remove Oxygen sensor (O2S) behind three way catalytic converter (TWC) G130 using tool from ring spanner set 3337.

Installing

Installation is performed in reverse order of removal. Note the following

Note. New oxygen sensor threads are coated with an assembly paste. This paste must not contact sensor openings. For a used oxygen sensor, only grease threads with high-temperature lubricant. This paste must not contact sensor openings; High-temperature lubricant . During installation, all cable ties and clips on transmission must be re-installed at the same location to prevent the oxygen sensor wiring from contacting the exhaust manifold.

1. Install exhaust system so it is free of tension. --> «26 - EXHAUST SYSTEM, EMISSION CONTROLS»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-engine-mechanical-engine-codes-bat-bnk) .

Tightening torques

Oxygen Sensor (O2S) 2 Behind Three Way Catalytic Converter (TWC) G131 after catalytic converter, bank 2 (left), removing and installing

Special tools, testers and auxiliary items required

1. Ring spanner 7-piece set 3337 for oxygen sensor.

Removing

Note. All cable ties which are opened or cut open when removing must be replaced in the same position when installing. Remove rear engine cover - arrows -.

1. Remove coolant expansion tank - arrow -.
2. Disconnect electrical connector at Engine Coolant Level (ECL) Warning Switch -F66- on bottom of coolant expansion tank.

1. Disconnect electrical connector from Engine Coolant Level (ECL) Warning Switch -F66- at bottom of coolant reservoir and set aside coolant reservoir with coolant hoses - 1 - and - 2 - connected.
2. Disconnect electrical connector - 4 -.
3. Remove retainer for the 4 electrical connections on bulkhead (to simplify removal and installation of oxygen sensor).
4. Expose oxygen sensor wire up to oxygen sensor.

Scheme 1297

1. Remove rear sound insulation.
2. Remove Oxygen Sensor (O2S) 2 Behind Three Way Catalytic Converter (TWC) G131 using tool 3337/5 and extension 3337/6 from ring spanner set 3337.

Installing

Installation is performed in reverse order of removal. Note the following

Note. New oxygen sensor threads are coated with an assembly paste. This paste must not contact sensor openings. For a used oxygen sensor, only grease threads with high-temperature lubricant. This paste must not contact sensor openings; High-temperature lubricant . During installation, all cable ties and clips on transmission must be re-installed at the same location to prevent the oxygen sensor wiring from contacting the exhaust manifold. Secure all hose connections using hose clamps appropriate for the model type .

Tightening torques

Left exhaust pipe with catalytic converter, removing and installing

Removing

Note. All cable ties which are opened or cut open when removing must be replaced in the same position when installing.

Remove rear engine cover - arrows -.

1. Remove coolant expansion tank - arrow -.
2. Disconnect electrical connector at Engine Coolant Level (ECL) Warning Switch -F66- on bottom of coolant expansion tank.

1. Disconnect electrical connector from Engine Coolant Level (ECL) Warning Switch -F66- at bottom of coolant reservoir and set aside coolant reservoir with coolant hoses - 1 - and - 2 - connected.

Scheme 1298

1. Disconnect electrical connector - 1 - for Oxygen Sensor (O2S) 2 Behind Three Way Catalytic Converter (TWC) -G131- and move wiring clear.
2. Remove nut - 2 - which is accessible from top for front exhaust pipe/exhaust manifold.

Note. To improve clarity, the removed engine is shown from the rear.

1. Remove left front wheel.

Note. Secure the brake disc with a wheel bolt.

Scheme 1299

1. Loosen quick-release fasteners - 1 - and - 2 - and remove sound insulation.

Scheme 1300

1. Remove heat shield - arrows - for left drive axle.

Scheme 1301

1. Unbolt cross piece for subframe - arrows -.

Scheme 1302

1. Unbolt front transverse beam - arrows -.

Scheme 1303

Separate exhaust system at left clamping sleeve - 2 -.

Note. Flex joint in front exhaust pipe must not be bent more than 10° , otherwise it may be damaged.

Scheme 1304

1. Remove bolts - 1 - at rear bracket for front exhaust pipe.

Scheme 1305

1. Remove bolt - 1 - at left bracket for front exhaust pipe.

1. Remove nuts - 1 - and - 3 - which are accessible from underneath for front exhaust pipe/exhaust manifold.

Note. To improve clarity, the removed engine is shown.

1. Remove front exhaust pipe with catalytic converter.

Installing

Installation is performed in reverse order of removal. Note the following

Note. Replace gaskets and self-locking nuts. During installation, all cable ties must be re-installed at the same locations. Wiring for oxygen sensors must always be secured in the same position when installing so that contact with the exhaust pipe is avoided.

1. Install cross piece for subframe --> «40 - FRONT SUSPENSION»(/audi/a6/6-2004-2008/remont/axle-shafts/#suspension-wheels-steering) .
2. Install front transverse beam --> «50 - BODY - FRONT»(/audi/a6/6-2004-2008/remont/door-locks-anti-theft-systems/#body-exterior) .
3. Align exhaust system free of tension --> «Exhaust system, installing free of tension»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__exhaust-system-installing-free-of-tension) .

Note. Individual components of exhaust system mounting.

Tightening torques

*Replace bolts and nuts.

Right exhaust pipe with catalytic converter, removing and installing

Removing

Note. All cable ties which are opened or cut open when removing must be replaced in the same position when installing.

1. Pull rear engine cover off - arrows -.

Scheme 1306

1. Disconnect check valve - 1 - from air duct hose.
2. Remove air duct hose by loosening hose clamp - 2 - and opening clips - arrows -.

1. Disconnect electrical connector - 1 - for Oxygen Sensor (O2S) Behind Three Way Catalytic Converter (TWC) -G130- and move wiring clear.

Scheme 1307

1. Remove nut - 2 - which is accessible from top for front exhaust pipe/exhaust manifold.

Note. To improve clarity, the removed engine is shown from the rear.

1. Remove right front wheel.

Note. Secure the brake disc with a wheel bolt.

1. Loosen quick-release fasteners - 1 - and - 2 - and remove sound insulation.

Scheme 1308

1. Remove heat shield - arrow - for right drive axle.

1. Unbolt cross piece for subframe - arrows -.

1. Unbolt front transverse beam - arrows -.

Separate exhaust system at right clamping sleeve - 1 -.

Note. Flex joint in front exhaust pipe must not be bent more than 10° , otherwise it may be damaged.

1. Remove bolts - 2 - at rear bracket for front exhaust pipe.

Scheme 1309

1. Remove bolt - 1 - at right bracket for front exhaust pipe.

1. Remove nuts - 1 - and - 3 - which are accessible from underneath for front exhaust pipe/exhaust manifold.

Note. To improve clarity, the removed engine is shown.

1. Remove front exhaust pipe with catalytic converter.

Installing

Installation is performed in reverse order of removal. Note following

Note. Replace gaskets, O-rings and self-locking nuts. Secure all hose connections using hose clamps appropriate for the model type . During installation, all cable ties must be re-installed at the same location. Wiring for oxygen sensors must always be secured in the same position when installing so that contact with the exhaust pipe is avoided.

1. Install cross piece for subframe --> «40 - FRONT SUSPENSION»(/audi/a6/6-2004-2008/remont/axle-shafts/#suspension-wheels-steering) .
2. Install front transverse beam --> «50 - BODY - FRONT»(/audi/a6/6-2004-2008/remont/door-locks-anti-theft-systems/#body-exterior) .
3. Align exhaust system free of tension --> «Exhaust system, installing free of tension»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__exhaust-system-installing-free-of-tension) .

Note. Individual components of exhaust system mounting.

Tightening torques

*Replace bolts and nuts.

Exhaust system, installing free of tension

Note. Align exhaust system when cold.

Vehicles without clamping sleeves between center and rear muffler

1. Loosen bolts of front clamping sleeves.

Scheme 1310

1. Slide exhaust system far enough forward - arrow - until pre-load on hangers at right on rear mufflers is - a - = 5 to 9 mm.
2. Tighten clamping sleeve mounting bolts uniformly to 23 Nm.
3. Align tailpipes.

Vehicles with clamping sleeves between center and rear muffler

Note. Only for vehicles with clamping sleeves between center and rear mufflers, the center muffler must also be aligned.

1. Loosen bolts of front and rear clamping sleeves.

1. Slide front section of exhaust system far enough forward - arrow - until pre-load on hangers at center muffler - a - = 5 to 9 mm.
2. Tighten bolts for front clamping sleeve uniformly to 23 Nm.

1. Push rear part of exhaust system far enough forward - arrow - so that pre-load at rear hangers of rear mufflers is - a - = 5 to 9 mm.
2. Align rear muffler horizontally.
3. Tighten bolts for rear clamping sleeve uniformly to 23 Nm.
4. Align tailpipes.

Scheme 1311

1. Check distance of tailpipes at left and right to bumper

1. Dimension - x - left = dimension - x - right

If necessary, correct dimension - x - as follows

Scheme 1312

1. Loosen threaded connection - arrow - of brace between exhaust pipes.
2. Adjust distance between rear mufflers.
3. Tighten threaded fastener to 25 Nm.

Scheme 1313

1. Check distances - y - and - z - of tailpipes to bumper

1. Dimension - y - = 17 to 19 mm
2. Dimension - z - = 0 ± 2 mm

1. If necessary, check whether exhaust system is aligned tension-free --> «Exhaust system, installing free of tension»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__exhaust-system-installing-free-of-tension) .

Exhaust system, checking for proper seal

1. Start engine and let run at idle.
2. Seal tailpipes with cloths or plug for duration of leak test.
3. Check for leaks by listening at connection areas of cylinder head/exhaust manifold, exhaust manifold/front exhaust pipe etc.
4. Repair leaks detected.

Secondary air injection (AIR) system

The Secondary Air Injection (AIR) system causes the catalytic converter to heat up more quickly, resulting in earlier operating readiness following a cold start.

Secondary Air Injection (AIR) system, principle and function

Principle

Due to the rich mixture during the cold start phase, the exhaust emissions contain an increased level of unburned hydrocarbons. The Secondary Air Injection (AIR) system improves the secondary oxidation within the catalytic converter, thereby reducing harmful emissions. The heat released by secondary oxidation shortens the start-up time of the catalytic converter considerably, as well as significantly improves emissions quality during the cold-running phase.

Function

Scheme 1314

1. In the cold start phase, the Motronic Engine Control Module (ECM) -J220- - item 3 - via Secondary Air Injection (AIR) Pump Relay -J299- - item 2 - activates the Secondary Air Injection (AIR) Pump Motor -V101- - item 1 -. Air reaches the combination valves for Secondary Air Injection (AIR) - 4 - and - 8 -.
2. The Secondary Air Injection (AIR) Solenoid Valve -N112- - 5 - is activated in parallel, which allows the vacuum to reach the combination valves for secondary air injection - 4 - and - 8 -. The appropriate combination valve for secondary air injection thereby opens the path for secondary air to the exhaust ports of the cylinder head.

Secondary Air Injection (AIR) system, component overview

1 - Secondary Air Injection (AIR) pump motor -V101

1. Location --> «Installed location of Secondary Air Injection (AIR) Pump Motor -V101»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk)
2. Checking --> «Voltage supply for Secondary Air Injection (AIR) Pump Motor -V101- , checking»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__voltage-supply-for-secondary-air-injection) .
3. Removing and installing --> «Secondary Air Injection (AIR) Pump Motor -V101- , removing and installing»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk) .

2 - Secondary Air Injection (AIR) pump relay -J299

1. Location --> «Installed location for Secondary Air Injection (AIR) Pump Relay -J299»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk)
2. Checking --> «Secondary Air Injection (AIR) Pump Relay -J299- , checking»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__secondary-air-injection-air-pump-relay) .

3 - Motronic Engine Control Module -J220

4 - Right combination valve for Secondary Air Injection (AIR)

1. Location «Installed location of combination valve for Secondary Air Injection (AIR)»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk)
2. Checking --> «Combination valve for Secondary Air Injection (AIR), checking function and for proper seal»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk) .
3. Removing and installing --> «Right combination valve for Secondary Air Injection (AIR), removing and installing»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk) .

5 - Secondary Air Injection (AIR) solenoid valve -N112

1. Location --> «Installed location of Secondary Air Injection (AIR) Solenoid Valve -N112»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk)
2. Checking --> «Secondary Air Injection (AIR) Solenoid Valve -N112- , checking»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__secondary-air-injection-air-solenoid-valve) .

6 - Non-return valve

1. Installation position: Arrow points in direction of flow (Scheme 1318)

7 - To intake manifold

8 - Left combination valve for Secondary Air Injection (AIR)

1. Location «Installed location of combination valve for Secondary Air Injection (AIR)»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk)
2. Checking --> «Combination valve for Secondary Air Injection (AIR), checking function and for proper seal»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk) .
3. Removing and installing --> «Left combination valve for Secondary Air Injection (AIR), removing and installing»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk) .

9 - Vacuum reservoir

1. Location: In left front wheelhousing behind wheelhousing liner.

Scheme 1315

1. Front at intake manifold - arrow -.

Scheme 1316

1. At right front in engine compartment below the long-member.

Scheme 1317

1. At position 2 in the 3-position relay carrier in electronics box, plenum chamber.

Scheme 1318

1. At rear of the cylinder heads.

Note. Left valve is displayed in illustration. Right valve similar.

Removing

1. Loosen quick-release fasteners - 1 - and - 2 - and remove front sound insulation.

Scheme 1319

1. Remove front bumper --> «63 - BUMPERS»(/audi/a6/6-2004-2008/remont/door-locks-anti-theft-systems/#body-exterior) .
2. Disconnect hoses - 3 - and - 4 - from Secondary Air Injection (AIR) Pump Motor -V101-.
3. Disconnect electrical connector - 1 - from Secondary Air Injection (AIR) Pump Motor -V101-.
4. Remove nuts - 2 - and - 5 - and remove Secondary Air Injection (AIR) pump motor -V101- from bracket.

Installing

Installation is performed in reverse order of removal. Note the following

1. Install front bumper --> «63 - BUMPERS»(/audi/a6/6-2004-2008/remont/door-locks-anti-theft-systems/#body-exterior) .

Tightening torque

Scheme 1320

Special tools, testers and auxiliary items required

1. Hose clamps up to 25 mm dia. 3094.

1. Remove rear engine cover - arrows -.

Scheme 1321

1. Clamp off the coolant hose - 2 - using Hose Clamps Up To 25mm Dia. 3094 and disconnect from the coolant expansion tank.
2. Remove coolant expansion tank - arrow -.
3. Disconnect electrical harness connector to Engine Coolant Level (ECL) Warning Switch -F66- on underside of coolant expansion tank and set aside.
4. If necessary, seal connection using appropriate plug.

Scheme 1322

1. Disconnect vacuum hoses at the positions indicated by the - arrows -.
2. Disconnect hose for crankcase ventilation at left cylinder head cover.

Scheme 1323

1. Disconnect electrical connector - arrow - from Camshaft Position (CMP) Sensor 2 -G163- on left cylinder head.

Note. Illustration shows the engine from the rear. Disconnect vacuum hose - 3 -.

1. Remove bolts - 4 -.
2. Disconnect electrical connector from oil pressure switch - 5 -.
3. Remove oil pressure switch.
4. Remove bolts - 1 - and - 2 -.

1. Swing combination valve out and remove bolts - 6 -.
2. Remove combination valve and connecting tube.

Note. Illustration shows the engine from the rear.

Installation is performed in reverse order of removal. Note the following

Note. Always replace gaskets and seals. Note installed position of seal between the cylinder head and connecting tube. Secure all hose connections using hose clamps appropriate for the model type .

1. Check coolant level. --> «19 - ENGINE - COOLING SYSTEM»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-engine-mechanical-engine-codes-bat-bnk) .

Tightening torques

1. Remove rear engine cover - arrows -.
2. Disconnect relevant Camshaft Position (CMP) Sensor electrical harness connector.

1. Remove fuel hose - 1 -.
2. Disconnect electrical connector - 2 - from Mass Air Flow (MAF) Sensor G70.
3. Remove Mass Air Flow (MAF) Sensor G70 from air duct hose - 3 -.

1. Remove upper part of air filter housing with Mass Air Flow (MAF) Sensor G70 - arrows -.
2. Remove resonator - 1 - in direction of the - arrow - from the air duct hose.

Scheme 1324

1. Disconnect brake booster vacuum hose - 1 - at bulkhead.
2. Loosen clamp - 3 - and remove air duct hose - 2 -.

Scheme 1325

1. Disconnect air hose - arrow - to right combination valve.

Note. Illustration shows engine from the rear.

Scheme 1326

Disconnect vacuum hose - 3 -.

1. Remove bolts - 1 - , - 2 - and - 4 - and remove right combination valve.

Note. Illustration shows engine from the rear.

Installation is performed in reverse order of removal. Note the following

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

Checking Secondary Air Injection (AIR) system for proper seal

1. Check connection pipes and hoses between Secondary Air Injection (AIR) pump motor and combination valves for proper seal. --> «Combination valve for Secondary Air Injection (AIR), checking function and for proper seal»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk) .
2. Check all hoses and hose connections for secure seating.

Final procedures

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

1. Check DTC memory..
2. If necessary, erase DTC memory..
3. If DTC memory was erased, generate readiness code..

1. End diagnosis and switch ignition off.

Scheme 1327

Special tools, testers and auxiliary items required

1. Hand vacuum pump V.A.G 1390.

Test requirements

1. Vacuum lines and hose connections free of leaks.
2. Vacuum lines not plugged.

Test sequence

1. Remove rear engine cover - arrows -.

Scheme 1328

1. Disconnect vacuum hose - arrow - at combination valve to be tested.

Note. The left combination valve is shown in the illustration.

1. Connect hand vacuum pump V.A.G 1390 to vacuum hose of combination valve to be checked.

Scheme 1329

1. Loosen quick-release fasteners - 1 - and - 2 - and remove front sound insulation. The rear section of sound insulation remains installed.

1. Disconnect pressure hose - arrow - from Secondary Air Injection (AIR) Pump Motor -V101-.
2. Blow with light pressure into pipe (do not use pressurized air).

Both combination valves must be closed, it must not be possible to blow through hose.

1. Operate hand vacuum pump V.A.G 1390.

The relevant combination valve must open, it must not be possible to blow through.

If relevant combination valve does not open

1. Replace faulty combination valve. --> «Left combination valve for Secondary Air Injection (AIR), removing and installing»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk) or --> «Right combination valve for Secondary Air Injection (AIR), removing and installing»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk) .

Secondary Air Injection (AIR) Solenoid Valve -N112- , checking

Special tools, testers and auxiliary items required

1. Multimeter V.A.G 1526 A or equivalent.
2. Voltage tester V.A.G 1527 B or equivalent.
3. Connector test set V.A.G 1594 C.
4. Adapter Cable (121-Point) VAG1598/31.

Test requirements

1. Fuse for Secondary Air Injection (AIR) solenoid valve OK..
2. Fuel Pump (FP) Relay OK. --> «Fuel Pump (FP) Relay J17 , checking»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__fuel-pump-fp-relay-j17) .
3. Ignition switched off.

Note. Voltage is supplied to the Secondary Air Injection (AIR) Solenoid Valve N112 via the Fuel Pump (FP) Relay J17.

Procedure

1. Remove front engine cover - arrow 1 - and - arrows 2 -.
2. Bring lock carrier into service position. --> «50 - BODY - FRONT»(/audi/a6/6-2004-2008/remont/door-locks-anti-theft-systems/#body-exterior) .

Checking internal resistance

1. Disconnect electrical harness connector from Secondary Air Injection (AIR) Solenoid Valve N112 - arrow -.

Scheme 1330

1. Using Multimeter V.A.G. 1526 A or equivalent, check Secondary Air Injection (AIR) Solenoid Valve -N112- for resistance.

Specified value: 19 to 27ohms.

If specified value is not obtained.

1. Replace Secondary Air Injection (AIR) Solenoid Valve -N112-.

If specified value is obtained.

1. Check voltage supply. «Checking voltage supply»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk) .

Checking voltage supply

1. Using Voltage Tester VAG1527B or equivalent, check the following wiring connection for voltage.

1. Operate starter briefly.

LED must light up.

If LED does not light up

1. Using Multimeter V.A.G. 1526 A or equivalent, check the wiring connection from the electrical connector terminal 2 to the Fuel Pump (FP) Relay J17 terminal 2 via the fuse for an open circuit.

Specified value: Wiring resistance max 1.5 ohms.

1. Check wiring for a short circuit to Battery positive (+) or an open circuit.
2. If necessary, repair faulty wiring connection.

If no malfunctions are found in the wiring

1. Check Fuel Pump (FP) Relay J17 --> «Fuel Pump (FP) Relay J17 , checking»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__fuel-pump-fp-relay-j17) .

If LED lights up

1. Check activation «Checking activation»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__checking-activation) .

Checking activation

1. Connect Adapter Cable (121-Point) VAG1598/31 to wiring harness of the Engine Control Module (ECM) J623 ; the ECM is not connected. --> «Diagnostic tester, connecting»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk) .
2. Using Multimeter V.A.G. 1526 A or equivalent, check the following wiring connections for open circuit.

Specified value: Wiring resistance max 1.5 ohms.

1. Check wiring for a short circuit to Battery positive (+) or an open circuit.
2. If necessary, repair faulty wiring connection.

If no malfunctions are found in the wiring

1. Replace Engine Control Module (ECM) J623 --> «Engine Control Module (ECM) J623 , replacing»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__engine-control-module-ecm-j623) .

Assembly is performed in reverse order of removal. Note the following

1. Install lock carrier with attachments. --> «50 - BODY - FRONT»(/audi/a6/6-2004-2008/remont/door-locks-anti-theft-systems/#body-exterior) .

Final procedures

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

1. Check DTC memory..
2. If necessary, erase DTC memory..
3. If DTC memory was erased, generate readiness code..

1. End diagnosis and switch ignition off.

Secondary Air Injection (AIR) Pump Relay -J299- , checking

Special tools, testers and auxiliary items required

1. Multimeter V.A.G 1526 A or equivalent.
2. Voltage tester V.A.G 1527 B or equivalent.
3. Connector test set V.A.G 1594 C.
4. Adapter Cable (121-Point) VAG1598/31.

Test requirements

1. Battery voltage at least 12.5 V.
2. Fuses for the secondary air pump OK.
3. The ignition switched off.

Test sequence

1. Remove rubber seal - 1 - from plenum chamber cover.
2. Remove plenum chamber cover - 2 -.

1. Using a screwdriver, remove wiper arms caps - arrows -.
2. Loosen wiper arm nuts - arrows - several turns.
3. Loosen wiper arms by gently rocking.
4. Remove wiper arm nuts and wiper arms.

1. Remove screws - arrows - retaining cowl grill - 1 -.
2. Remove cowl grill from windshield.

1. Remove screws - arrows - and electronics box cover from electronics box.
2. Connect Adapter Cable (121-Point) VAG1598/31 to the wiring harness of the Engine Control Module (ECM) J623 ; the ECM is not connected. --> «Diagnostic tester, connecting»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk) .
3. Using connectors from the Connector test set V.A.G 1594 C , bridge terminals 1 and 46 together on the Adapter Cable (121-Point) VAG1598/31.

Scheme 1331

1. Switch the ignition on.

The Secondary Air Injection (AIR) Pump Relay J299 , position 3 (in 3-pin relay carrier, E-box plenum chamber, right) must engage and the Secondary Air Injection (AIR) Pump Motor V101 must run.

1. Switch ignition off.

If Secondary Air Injection (AIR) Pump Motor V101 runs

1. Check voltage supply for Secondary Air Injection (AIR) Pump Relay J299 --> «Checking the voltage supply of the Secondary Air Injection (AIR) Pump Relay J299.»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__checking-the-voltage-supply-of-the) .
2. Check activation of Secondary Air Injection (AIR) Pump Relay J299 «Check activation of the Secondary Air Injection (AIR) pump relay»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__check-activation-of-the-secondary-air)

If Secondary Air Injection (AIR) Pump Motor V101 does not run

1. Check voltage supply of Secondary Air Injection (AIR) Pump Motor V101 --> «Voltage supply for Secondary Air Injection (AIR) Pump Motor -V101- , checking»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__voltage-supply-for-secondary-air-injection) .

Checking the voltage supply of the Secondary Air Injection (AIR) Pump Relay J299.

1. Remove Secondary Air Injection (AIR) Pump Relay J299 from position 3 in the (in 3-pin relay carrier, E-box plenum chamber, right).
2. Using Multimeter V.A.G. 1526 A or equivalent, check following wiring connection for voltage.

Specified value: approx. battery voltage.

If specified value is not obtained

1. Using Multimeter V.A.G. 1526 A or equivalent, check wiring connection from the Motronic Engine Control Module (ECM) Power Supply Relay J271 terminal 2 to Secondary Air Injection (AIR) Pump Relay J299 terminal 2 for an open circuit.

Specified value: Wiring resistance max 1.5 ohms.

1. Check wiring for a short circuit to Battery positive (+) or an open circuit.
2. If necessary, repair faulty wiring connection.

If specified value is obtained

1. Using Multimeter V.A.G. 1526 A or equivalent, check wiring connection for voltage.

1. Operate starter briefly (engine can also start).

Specified value: approx. battery voltage

1. Switch ignition off.

If specified value is not obtained

1. Using Multimeter V.A.G. 1526 A or equivalent, check wiring connection from the Secondary Air Injection (AIR) Pump Relay -J299- terminal 6 to Fuel Pump (FP) Relay J17 terminal 2 via fuse for an open circuit.

Specified value: Wiring resistance max 1.5 ohms.

1. Check wiring for a short circuit to Battery positive (+) or an open circuit.
2. If necessary, repair faulty wiring connection.

If specified value is obtained

1. Check activation «Check activation of the Secondary Air Injection (AIR) pump relay»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__check-activation-of-the-secondary-air) .

Check activation of the Secondary Air Injection (AIR) pump relay

1. Connect Adapter Cable (121-Point) VAG1598/31 to wiring harness of Engine Control Module (ECM) J623 ; the ECM is not connected. --> «Diagnostic tester, connecting»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk) .
2. Using Adapter Cable (121-Point) VAG1598/31 and Multimeter V.A.G 1526 A or equivalent, check the following wire connection for an open circuit.

Specified value: Wire resistance max 1.5 ohms.

1. Check wiring for a short circuit to Battery positive (+) or an open circuit.
2. If necessary, repair faulty wiring connection.

If no malfunctions are detected

1. Replace Secondary Air Injection (AIR) Pump Relay -J299-.

Final procedures

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

1. Check DTC memory..
2. If necessary, erase DTC memory..
3. If DTC memory was erased, generate readiness code..

1. End diagnosis and switch ignition off.

Voltage supply for Secondary Air Injection (AIR) Pump Motor -V101- , checking

1. Loosen quick-release fasteners - 1 - and - 2 - and remove front sound insulation.

1. Disconnect electrical connector - 1 - from Secondary Air Injection (AIR) Pump Motor -V101-.

1. Using voltage tester V.A.G 1527 B or equivalent, check for voltage between terminals - 1 - and - 2 -.
2. Operate starter briefly (engine can also start).

LED should blink.

1. Switch ignition off.

If LED does not blink

1. Using Multimeter V.A.G. 1526 A or equivalent, check wiring connection from Secondary Air Injection (AIR) Pump Relay -J299- (in relay carrier in electronics box, plenum chamber, position 3) terminal 8 to Secondary Air Injection (AIR) Pump Motor -V101- electrical connector terminal 2 for an open circuit.
2. Using Multimeter V.A.G. 1526 A or equivalent, check Secondary Air Injection (AIR) Pump Motor -V101- electrical connector terminal 1 to Ground (GND) for an open circuit.

Specified value: Wire resistance max 1.5 ohms.

1. Check wiring for a short circuit to Battery positive (+) or an open circuit.
2. If necessary, repair faulty wiring connection.

If no malfunctions are detected

1. Replace Secondary Air Injection (AIR) Pump Motor -V101- --> «Secondary Air Injection (AIR) Pump Motor -V101- , removing and installing»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk) .

Final procedures

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

1. Check DTC memory..
2. If necessary, erase DTC memory..
3. If DTC memory was erased, generate readiness code..

1. End diagnosis and switch ignition off.

General notes on ignition system

1. For the electric components to work properly, a voltage of at least 12.5 V is required.
2. If the engine only starts briefly and then turns off again after troubleshooting, repair or checking of the components, it may be that the immobilizer is blocking the Engine Control Module (ECM) J623. DTC memory must then be checked and if necessary, the Engine Control Module (ECM) J623 must be adapted. --> «Engine Control Module (ECM) J623 , replacing»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__engine-control-module-ecm-j623) .
3. It is possible that the Engine Control Module (ECM) J623 will recognize a malfunction and store a DTC during some tests. After completing all tests and repairs, the DTC memory should therefore be checked and erased if necessary.

The following work steps must be performed in the mentioned sequence

1. Check DTC memory..
2. If necessary, erase DTC memory..
3. If DTC memory was erased, generate readiness code..

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

1. Do not touch or disconnect the ignition wires when the engine is running or turning at starting RPM.
2. Always switch the ignition off before disconnecting or reconnecting the wires for the injection and ignition system, including the high voltage wiring and test leads.
3. If the engine is to be cranked at the starting RPM without starting (e.g. for compression testing), disconnect the electrical connector from the ignition coils and the fuel injectors.
4. Always switch the ignition off before cleaning the engine.

1. Be sure to activate the vehicle features (radio/radio-navigation system, clock, electric window regulators) according to the owners manual when the battery is reconnected.
2. Switch the ignition off and remove the ignition key.

Technical data, ignition

* Regulated by the Engine Control Module (ECM) J623 and is not adjustable.

Ignition Coil with Power Output Stage N70, N127, N291, N292, N323, N324, N325, N326 , checking

Special tools, testers and auxiliary items required

1. Multimeter V.A.G 1526 A or equivalent.
2. Voltage Tester VAG1527B or equivalent.
3. Adapter Cable (121-Point) VAG1598/31.
4. Connector Test Set VAG1594C.

Note. The ignition coils and power output stages are one component and cannot be replaced individually.

Test requirement

1. The fuses for the engine electronics OK..
2. Fuel Pump (FP) Relay OK. --> «Fuel Pump (FP) Relay J17 , checking»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__fuel-pump-fp-relay-j17) .

Procedure

Recognize a nonfunctional or misfiring cylinder as follows

1. Compare the spark plugs of all the cylinders to each other. Check the electrodes for carbon fouling.

If faulty a cylinder is recognized

1. Switch spark plug from faulty cylinder with one from another cylinder.

If malfunction follows the spark plug

1. Replace spark plug.

If malfunction remains at the original cylinder

1. Switch ignition coil from faulty cylinder with one from another cylinder.

If the malfunction follows the ignition coil

1. Replace ignition coil.

Checking Ground (GND) connection

1. Remove front engine cover - arrows -1- and -2 -.

1. Remove rear engine cover - arrows -.

Cylinder bank 1 (right)

1. Remove fuel hose - 1 -.
2. Disconnect electrical connector - 2 - from Mass Air Flow (MAF) Sensor G70.
3. Remove Mass Air Flow (MAF) Sensor G70 from air duct hose - 3 -.

1. Remove upper part of air filter housing with Mass Air Flow (MAF) Sensor G70 - arrows -.

1. Remove resonator - 1 - in direction of - arrow - from air duct hose.
2. Disconnect brake booster vacuum hose - 1 - at bulkhead.

Scheme 1332

1. Loosen clamp - 3 - and remove air duct hose - 2 -.
2. Remove air duct screws - arrows -.

Scheme 1333

1. Remove air ducts - 1 - and - 2 -.
2. Remove electrical harness screws - 5 - and - 6 -.
3. Disconnect electrical connectors - 1 - , - 2 - , - 3 - , and - 4 - from ignition coils - arrows -.

Cylinder bank 2 (left)

1. Remove screw - arrow - retaining coolant reservoir.

Scheme 1334

1. Disconnect electrical connector from Engine Coolant Level (ECL) Warning Switch F66 at bottom of coolant reservoir and set aside coolant reservoir with coolant hoses - 1 - and - 2 - connected.
2. Remove electrical harness screws - 5 - and - 6 -.
3. Disconnect electrical connectors - 1 - , - 2 - , - 3 - , and - 4 - from ignition coils - arrows -.

Checking voltage supply

1. Using Voltage Tester VAG1527B or equivalent, check the following wiring connections for voltage

LED must light up.

If LED does not light up

Checking resistance

1. Using Multimeter V.A.G 1526 A or equivalent, check the following wiring connection for an open circuit

Specified value: Wire resistance max 1.5 ohms.

If specification is not obtained

1. Check wiring for a short circuit to Battery positive (+) or an open circuit.
2. If necessary, repair wiring connection.

If no malfunctions are detected

1. Switch ignition on.
2. Using Multimeter V.A.G 1526 A or equivalent, check the following wiring connection for voltage

Specified value: approx. battery voltage.

1. Switch ignition off.

If specified value is obtained

1. Check activation of the power output stages.

If specified value is not obtained

1. Remove rubber seal - 1 - from plenum chamber cover.
2. Remove plenum chamber cover - 2 -.

1. Using a screwdriver, remove wiper arms caps - arrows -.
2. Loosen wiper arm nuts - arrows - several turns.
3. Loosen wiper arms by gently rocking.
4. Remove wiper arm nuts and wiper arms.

1. Remove screws - arrows - retaining cowl grill - 1 -.
2. Remove cowl grill from windshield.

1. Remove screws - arrows - and electronics box cover from the electronics box.

1. Remove Motronic Engine Control Module (ECM) Power Supply Relay J271 from position 3 of the E-Box plenum chamber, left.

1. Using Multimeter V.A.G 1526 A or equivalent, check wiring connection from the power supply relay carrier position 3, terminal 2 to the ignition coil wiring harness connector terminal 1.

Specified value: Wire resistance max 1.5 ohms.

If specified value is not obtained

1. Repair the wiring.

If specified value is obtained

1. Replace faulty ignition coil. --> «28 - IGNITION/GLOW PLUG SYSTEM»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-fuel-injection-and-ignition-engine-codes-bat-bnk) .

Checking activation of power output stages

Note. Fuel must not be injected during the test to avoid damaging the catalytic converter.

1. Disconnect fuel injector electrical harnesses - 1 - and - 5 - from fuel injectors.

1. Using Voltage Tester VAG1527B or equivalent, and a probe from Connector Test Set VAG1594C. Connect ignition coil electrical harness connector terminals 2 and 3 together and check for voltage leaving the ignition coil electrical harness connector connected to ignition coil.
2. Operate starter briefly.

LED must blink (brief blink signal).

1. Switch ignition off.

If LED blinks

1. Replace faulty ignition coil with power output stage.

If LED does not blink

1. Connect Adapter Cable (121-Point) VAG1598/31 to the wiring harness of the Engine Control Module (ECM) J623 ; the ECM is not connected. --> «Diagnostic tester, connecting»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk) .
2. Using Adapter Cable (121-Point) VAG1598/31 and Multimeter V.A.G 1526 A or equivalent, check the following wiring connections for an open circuit.

Specified value: Wire resistance max 1.5 ohms.

If specification is not obtained

1. Check wiring for a short circuit to Battery positive (+) or an open circuit.
2. If necessary, repair wiring connection.

If no malfunctions are found in the wiring

1. Replace Engine Control Module (ECM) J623. --> «Engine Control Module (ECM) J623 , replacing»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__engine-control-module-ecm-j623) .

Assembly is performed in reverse order of removal. Note the following

Tighten torque

Final procedures

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

1. Check DTC memory..
2. If necessary, erase DTC memory..
3. If DTC memory was erased, generate readiness code..

1. End diagnosis and switch ignition off.

Knock Sensor (KS) , checking

The following procedure is used to check Knock Sensor (KS) 1 G61 , Knock Sensor (KS) 2 G66 , Knock Sensor 3 G198 , and Knock sensor 4 G199.

Special tools, testers and auxiliary items required

1. Multimeter V.A.G 1526 A or equivalent.
2. Adapter Cable (121-Point) VAG1598/31.

Note. Cylinders 1 and 2 as well as 3 and 4 (bank 1) are monitored by Knock Sensor (KS) 1 G61 and Knock Sensor (KS) 2 G66. Cylinders 5 and 6 as well as 7 and 8 (bank 2) are monitored by Knock Sensor 3 G198 and Knock sensor 4 G199. Knock sensors themselves cannot be checked electrically. When servicing terminals in the harness connector of knock sensors, use only gold-plated terminals. For the knock sensors to function properly, it is important that the tightening torque be exactly 20 Nm. Contact surfaces between the Knock Sensors and cylinder block must be free of corrosion, dirt and grease. Check the Knock Sensors electrical harness connectors for corrosion.

Test requirement

1. Ignition switched off.

Checking knock sensor and wiring

1. Remove front engine cover - arrows -1- and -2 -.

Scheme 1335

1. Disconnect electrical harness connector - 1 - , - 2 - , - 5 - or - 6 - of the knock sensor to be checked.

1 - Knock Sensor (KS) 1 G61

2 - Knock Sensor (KS) 2 G66

5 - Knock Sensor 3 G198

6 - Knock sensor 4 G199

1. Check as follows

Scheme 1336

1. Using the Multimeter V.A.G. 1526 A or equivalent, check all three terminals of the knock sensor for a short circuit to each other as follows

Specified value: 0 ohms (no continuity).

The wiring must not have any connection to each other.

1. If there is a connection, replace faulty knock sensor.

If no malfunction can be found

Check wiring from knock sensors to Engine Control Module (ECM)

1. Connect Adapter Cable (121-Point) VAG1598/31 to wiring harness of Engine Control Module (ECM) J623 ; the ECM is not connected. --> «Diagnostic tester, connecting»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk) .
2. Using Adapter Cable (121-Point) VAG1598/31 and Multimeter V.A.G 1526 A or equivalent, check the following wiring connections for an open circuit.

1. Knock Sensor (KS) 1 -G61

1. Knock Sensor (KS) 2 -G66

1. Knock Sensor 3 G198

1. Knock sensor 4 G199

Specified value: Wire resistance max 1.5 ohms.

If specification is not obtained

1. Check wiring for a short circuit to Battery positive (+) or an open circuit.
2. If necessary, repair wiring connection.

If no malfunction can be found

1. Replace Engine Control Module (ECM) J623. --> «Engine Control Module (ECM) J623 , replacing»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__engine-control-module-ecm-j623) .

Assembly is performed in reverse order of removal. Note the following

Tighten torque

Final procedures

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

1. Check DTC memory..
2. If necessary, erase DTC memory..
3. If DTC memory was erased, generate readiness code..

1. End diagnosis and switch ignition off.

Camshaft Position (CMP) Sensors , checking

This procedure is used to check Camshaft Position (CMP) Sensors G40 and G163.

Special tools, testers and auxiliary items required

1. Multimeter V.A.G 1526 A or equivalent.
2. Voltage Tester VAG1527B or equivalent.
3. Adapter Cable (121-Point) VAG1598/31.
4. Connector Test Set VAG1594C.

Test requirements

1. Ignition switched off.

Procedure

1. Remove front engine cover - arrows -1- and -2 -.

1. Remove rear engine cover - arrows -.
2. Disconnect relevant Camshaft Position (CMP) Sensor electrical harness connector.

Cylinder bank 1 (right)

1. Remove fuel hose - 1 -.
2. Disconnect electrical connector - 2 - from Mass Air Flow (MAF) Sensor G70.
3. Remove Mass Air Flow (MAF) Sensor G70 from air duct hose - 3 -.
4. Remove upper part of air filter housing with Mass Air Flow (MAF) Sensor G70 - arrows -.

1. Remove resonator - 1 - in direction of - arrow - from air duct hose.

1. Disconnect brake booster vacuum hose - 1 - at bulkhead.
2. Loosen clamp - 3 - and remove air duct hose - 2 -.

Scheme 1337

1. Disconnect electrical harness connector - arrow - from Camshaft Position (CMP) Sensor G40 at rear of right cylinder head.

Cylinder bank 2 (left)

1. Remove screw - arrow - retaining coolant reservoir.

1. Disconnect electrical connector from Engine Coolant Level (ECL) Warning Switch F66 at bottom of coolant reservoir and set aside the coolant reservoir with coolant hoses - 1 - and - 2 - connected.
2. Disconnect electrical harness connector - arrow - from Camshaft Position (CMP) Sensor 2 G163 at rear of the left cylinder head.

Checking activation

1. Using Voltage Tester VAG1527B or equivalent, and a probe from Connector Test Set VAG1594C. Connect Camshaft position (CMP) sensor electrical harness connector terminals 1 and 2 together and check for voltage leaving Camshaft position (CMP) sensor electrical harness connector connected to Camshaft position (CMP) sensor.
2. Operate starter for a few seconds.

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 significantly brighter during activation.

1. Switch ignition off.

If LED blinks

1. Replace faulty Camshaft Position (CMP) Sensor.

If LED does not blink

Checking voltage supply

1. Using Multimeter V.A.G 1526 A or equivalent, check the following wiring connection for voltage

1. Switch ignition on.

Specified value: about 5 V.

1. Switch ignition off.

Checking signal wire

1. Using Multimeter V.A.G 1526 A or equivalent, check the following wiring connection for voltage

1. Switch ignition on.

Specified value: approx. battery voltage.

1. Switch ignition off.

Checking Ground (GND)

1. Using Multimeter V.A.G 1526 A or equivalent, check the following wiring connection for voltage

Specified value: about 10 V.

If specification is not obtained

1. Check wiring for a short circuit to Battery positive (+) or an open circuit.
2. If necessary, repair the wiring connection.

If no malfunction can be found

Checking wire connections between Camshaft Position (CMP) sensor and Engine Control Module (ECM)

1. Connect Adapter Cable (121-Point) VAG1598/31 to wiring harness of Engine Control Module (ECM) J623 ; the ECM is not connected. --> «Diagnostic tester, connecting»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk) .

1. Using Adapter Cable (121-Point) VAG1598/31 and Multimeter V.A.G 1526 A or equivalent, check the following wiring connections for an open circuit.

1. Camshaft Position (CMP) Sensor G40 (bank 1).

1. Camshaft Position (CMP) Sensor 2 G163 (bank 2).

Specified value: Wire resistance max 1.5 ohms.

If specification is not obtained

1. Check wiring for a short circuit to Battery positive (+) or an open circuit.
2. If necessary, repair wiring connection.

If no malfunction can be found

1. Replace Engine Control Module (ECM) J623. --> «Engine Control Module (ECM) J623 , replacing»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__engine-control-module-ecm-j623) .

Assembly is performed in reverse order of removal. Note the following

Final procedures

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

1. Check DTC memory..
2. If necessary, erase DTC memory..
3. If DTC memory was erased, generate readiness code..

1. End diagnosis and switch ignition off.

Camshaft Adjustment Valve , checking

This procedure is used to check the Camshaft Adjustment Valves N205 and N208.

Special tools, testers and auxiliary items required

1. Multimeter V.A.G 1526 A or equivalent.
2. Voltage Tester VAG1527B or equivalent.
3. Adapter Cable (121-Point) VAG1598/31.
4. Connector Test Set VAG1594C.

Test requirements

1. Fuse for valve for camshaft adjustment OK..
2. Ignition switched off.
3. The Fuel Pump (FP) Relay J17 OK. --> «Fuel Pump (FP) Relay J17 , checking»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__fuel-pump-fp-relay-j17) .

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

Test sequence

Cylinder bank 1 (right)

1. Disconnect electrical connector - 2 - from Camshaft Adjustment Valve 1 N205.

Cylinder bank 2 (left)

1. Remove screw - arrow - retaining coolant reservoir.

1. Disconnect electrical connector from Engine Coolant Level (ECL) Warning Switch F66 at the bottom of coolant reservoir and set aside the coolant reservoir with coolant hoses - 1 - and - 2 - connected.
2. Disconnect electrical connector - 3 - from Camshaft Adjustment Valve 2 N208.

Checking internal resistance

1. Using Multimeter V.A.G 1526 A or equivalent, check the following wiring connections for open circuit.

Specified value: 8 to 13 ohms.

If specified value is not obtained

1. Replace faulty Camshaft Adjustment Valve.

If specified value is obtained

Checking voltage supply

1. Using Voltage Tester VAG1527B or equivalent, check the following wiring connection for voltage.

1. Operate starter briefly

LED must light up.

1. Switch ignition off.

If LED does not light up

1. Check wiring connection from terminal 1 of the electrical harness connector via fuse to Motronic Engine Control Module (ECM) Power Supply Relay J271 terminal 2 for an open circuit

Specified value: Wire resistance max 1.5 ohms.

If specified value is not obtained

1. Check wiring for a short circuit to Battery positive (+) or an open circuit.
2. If necessary, repair wiring connection.

If LED lights up.

Checking activation

1. Connect Adapter Cable (121-Point) VAG1598/31 to wiring harness of Engine Control Module (ECM) J623 ; the ECM is not connected. --> «Diagnostic tester, connecting»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk) .

1. Using Adapter Cable (121-Point) VAG1598/31 and Multimeter V.A.G 1526 A or equivalent, check the following wiring connections for an open circuit.

1. Camshaft Adjustment Valve 1 N205 (bank 1).

1. Camshaft Adjustment Valve 2 N208 (bank 2).

If specification is not obtained

1. Check wiring for a short circuit to Battery positive (+) or an open circuit.
2. If necessary, repair wiring connection.

If no malfunctions are found in the wiring

1. Replace Engine Control Module (ECM) J623. --> «Engine Control Module (ECM) J623 , replacing»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__engine-control-module-ecm-j623) .

If no malfunctions are detected

1. Replace mechanical camshaft adjuster. --> «15 - ENGINE - CYLINDER HEAD, VALVETRAIN»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-engine-mechanical-engine-codes-bat-bnk) .

Assembly is performed in reverse order of removal. Note the following

Final procedures

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

1. Check DTC memory..
2. If necessary, erase DTC memory..
3. If DTC memory was erased, generate readiness code..

1. End diagnosis and switch ignition off.

Electrical components for regulating transmission, checking

Safety precautions

Note. Certainly you have received an electrical shock once before when touching something made out of metal. The reason for this is the electrostatic charge of the human body. This charge can lead to functional problems by touching the electrical components of the transmission and selector lever mechanism. Touch a grounded object, e.g. a water pipe or a hoist, before working on the electrical components! Do not make direct contact on connector terminals of the Mechatronic unit! The batteries must only be disconnected and connected with the ignition switched off, since the Mechatronic unit can otherwise be damaged.

If special testing equipment is required during road test. Note the following

1. Test equipment must always be secured to the rear seat and operated from there by a second person.

If test and measuring equipment is operated from the passenger seat, the person seated there could be injured in the event of an accident involving deployment of the passenger-side airbag.

Note. For the electric components to work properly, a voltage of at least 12.5 V is required. Transmission Control Module (TCM) is equipped with On Board Diagnostic (OBD). It is possible that the control module will recognize a malfunction and store a DTC during some tests. Therefore the following work steps must be performed in the mentioned sequence after ending all tests and repairs.

1. Check DTC memory..
2. If necessary, erase DTC memory of Transmission Control Module (TCM) J217.
3. Generate readiness code..

Multi-Function Transmission Range (TR) Switch, checking

Note. The Multi-Function Transmission Range (TR) Switch F125 is a component of the Mechatronic unit in the transmission.

Requirements

1. Control Module with indicator unit in Instrument Cluster Control Module J285 must be OK.
2. The battery voltage must be at least 12.5 Volts.
3. All electrical consumers must be switched off.
4. The parking brake must be engaged.

1. The elector lever must be in the "P" position.
2. The Ground (GND) connections to transmission must be OK.

Test sequence

1. Switch the ignition on.
2. Depress brake pedal and maintain depressed.
3. Shift selector lever into all positions.

The selector lever position must correspond to the display of the Control Module with the indicator unit in the Instrument Cluster Control Module J285.

1. Switch ignition off.

Scheme 1338

If selector lever position does not correspond to the display of the Control Module with indicator unit in the Instrument Cluster Control Module J285

1. Disconnect electrical connector in direction of - arrow - and remove it from Transmission Control Module (TCM) J217.
2. Observe safety precautions.
3. Check electrical harness connector for contact corrosion and ingress of water.

If electrical harness connector is not OK

1. Repair malfunction and repeat test sequence.

If electrical harness connector is OK

1. Check wiring according to wiring diagram

If no malfunctions are found in wiring

1. Replace Mechatronic unit in transmission: --> «38 - AUTOMATIC TRANSMISSION - GEARS, HYDRAULIC CONTROLS»(ref-281381-S08686013262008031100000) .

Note. The Transmission Control Module (TCM) J217 is a component of the Mechatronic unit and cannot be replaced separately.

Final procedures

1. Check DTC memory.
2. If necessary, erase DTC memory of Transmission Control Module (TCM) J217.
3. Generate readiness code.

Sensor for transmission RPM, checking

Note. The Transmission Input Speed (RPM) Sensor G182 is a component of the Mechatronic unit in the transmission.

Requirements

1. The battery voltage must be at least 12.5 Volts.
2. All electrical consumers must be switched off.
3. The parking brake must be engaged.
4. The elector lever must be in the "P" position.

1. The Ground (GND) connections to transmission must be OK.

Test sequence

1. Disconnect electrical connector in direction of - arrow - and remove it from Transmission Control Module (TCM) J217.
2. Observe safety precautions.
3. Check electrical harness connector for contact corrosion and ingress of water.

If electrical harness connector is not OK

1. Repair malfunction.

If electrical harness connector is OK

1. Check wiring according to wiring diagram

If no malfunctions are found in the wiring

1. Replace Mechatronic unit in transmission: --> «38 - AUTOMATIC TRANSMISSION - GEARS, HYDRAULIC CONTROLS»(ref-281381-S08686013262008031100000) .

Note. The Transmission Input Speed (RPM) Sensor G182 is a component of the Mechatronic unit and cannot be replaced separately.

Final procedures

1. Check DTC memory..
2. If necessary, erase DTC memory of Transmission Control Module (TCM) J217..
3. Generate readiness code..

Sensor for transmission output RPM, checking

Note. The Transmission Output Speed (RPM) Sensor G195 is a component of the Mechatronic unit in the transmission.

Requirements

1. The battery voltage must be at least 12.5 Volts.
2. All electrical consumers must be switched off.
3. The parking brake must be engaged.
4. The elector lever must be in the "P" position.

1. The Ground (GND) connections to transmission must be OK.

Test sequence

1. Disconnect electrical connector in direction of - arrow - and remove it from Transmission Control Module (TCM) J217.
2. Observe safety precautions.
3. Check electrical harness connector for contact corrosion and ingress of water.

If electrical harness connector is not OK

1. Repair malfunction.

If electrical harness connector is OK

1. Check wiring according to wiring diagram

If no malfunctions are found in the wiring

1. Replace Mechatronic unit in transmission: --> «38 - AUTOMATIC TRANSMISSION - GEARS, HYDRAULIC CONTROLS»(ref-281381-S08686013262008031100000) .

Note. The Transmission Output Speed (RPM) Sensor G195 is a component of the Mechatronic unit and cannot be replaced separately.

Final procedures

1. Check DTC memory..
2. If necessary, erase DTC memory of Transmission Control Module (TCM) J217..
3. Generate readiness code..

Transmission Fluid Temperature Sensor, checking

Note. The Transmission Fluid Temperature Sensor G93 is a component of the Mechatronic unit in the transmission.

Requirements

1. The battery voltage must be at least 12.5 Volts.
2. All electrical consumers must be switched off.
3. The parking brake must be engaged.
4. The elector lever must be in the "P" position.

1. The Ground (GND) connections to transmission must be OK.

Test sequence

1. Disconnect electrical connector in direction of - arrow - and remove it from Transmission Control Module (TCM) J217.
2. Observe safety precautions.
3. Check electrical harness connector for contact corrosion and ingress of water.

If electrical harness connector is not OK

1. Repair malfunction.

If electrical harness connector is OK

1. Check wiring according to wiring diagram

If no malfunctions are found in the wiring

1. Replace Mechatronic unit in transmission: --> «38 - AUTOMATIC TRANSMISSION - GEARS, HYDRAULIC CONTROLS»(ref-281381-S08686013262008031100000) .

Note. The Transmission Fluid Temperature Sensor G93 is a component of the Mechatronic unit and cannot be replaced separately.

Final procedures

1. Check DTC memory..
2. If necessary, erase DTC memory of Transmission Control Module (TCM) J217..
3. Generate readiness code..

Solenoid valve 1, checking

Note. The Solenoid Valve 1 N88 is a component of the Mechatronic unit in the transmission.

Requirements

1. The battery voltage must be at least 12.5 Volts.
2. All electrical consumers must be switched off.
3. The parking brake must be engaged.
4. The elector lever must be in the "P" position.

1. The Ground (GND) connections to transmission must be OK.

Test sequence

1. Disconnect electrical connector in direction of - arrow - and remove it from Transmission Control Module (TCM) J217.
2. Observe safety precautions.
3. Check electrical harness connector for contact corrosion and ingress of water.

If electrical harness connector is not OK

1. Repair malfunction.

If electrical harness connector is OK

1. Check wiring according to wiring diagram

If no malfunctions are found in the wiring

1. Replace Mechatronic unit in transmission: --> «38 - AUTOMATIC TRANSMISSION - GEARS, HYDRAULIC CONTROLS»(ref-281381-S08686013262008031100000) .

Note. The Solenoid Valve 1 N88 is a component of the Mechatronic unit and cannot be replaced separately.

Final procedures

1. Check DTC memory..
2. If necessary, erase DTC memory of Transmission Control Module (TCM) J217..
3. Generate readiness code..

Pressure regulator valves, checking

Note. The Automatic Transmission Pressure Regulating Valve 1 N215 , Automatic Transmission Pressure Regulating Valve 2 N216 , Automatic Transmission Pressure Regulating Valve 3 N217 , Automatic Transmission Pressure Regulating Valve 4 N218 , Automatic Transmission Pressure Regulating Valve 5 N233 , and the Automatic Transmission Pressure Regulating Valve 6 N371 are components of the Mechatronic unit in the transmission.

Requirements

1. The battery voltage must be at least 12.5 Volts.
2. All electrical consumers must be switched off.
3. The parking brake must be engaged.
4. The elector lever must be in the "P" position.

1. The Ground (GND) connections to transmission must be OK.

Test sequence

1. Disconnect electrical connector in direction of - arrow - and remove it from Transmission Control Module (TCM) J217.
2. Observe safety precautions.
3. Check electrical harness connector for contact corrosion and ingress of water.

If electrical harness connector is not OK

1. Repair malfunction.

If electrical harness connector is OK

1. Check wiring according to wiring diagram

If no malfunctions are found in the wiring

1. Replace Mechatronic unit in transmission: --> «38 - AUTOMATIC TRANSMISSION - GEARS, HYDRAULIC CONTROLS»(ref-281381-S08686013262008031100000) .

Note. The Automatic Transmission Pressure Regulating Valve 1 N215 , Automatic Transmission Pressure Regulating Valve 2 N216 , Automatic Transmission Pressure Regulating Valve 3 N217 , Automatic Transmission Pressure Regulating Valve 4 N218 , Automatic Transmission Pressure Regulating Valve 5 N233 , and the Automatic Transmission Pressure Regulating Valve 6 N371 are components of the Mechatronic unit in the transmission and cannot be replaced separately.

Final procedures

1. Check DTC memory..
2. If necessary, erase DTC memory of Transmission Control Module (TCM) J217..
3. Generate readiness code..

Function

The Transmission Control Module (TCM) J217 receives information from the components that affect the shifts and forwards this information to the pressure regulator valves of the mechatronic, which control the slide valves in the valve body.

Transmission Control Module (TCM) J217 , replacing

Note. The Transmission Control Module (TCM) J217 is a component of the mechatronic unit in the transmission and cannot be replaced separately. 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 Transmission Control Module (TCM) J217. So that this system cannot be circumvented, it is necessary to perform adaptation of the anti-theft immobilizer using the Vehicle Diagnosis Service Syst. VAS5052 in the On Board Diagnostic (OBD) function. If the Transmission Control Module (TCM) J217 must be replaced, the vehicle may be taken to the nearest Audi dealership for instructions on obtaining a Vehicle Diagnosis Service Syst. VAS5052.

Work procedure

Check control module identification of the previous Transmission Control Module (TCM) J217 as follows

1. Connect Vehicle Diagnosis Service Syst. VAS5052. --> «Diagnostic tester, connecting»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk) .
2. Switch ignition on.
3. In diagnostic function "address word 33 - OBD" select "Diagnostic mode 9: Vehicle information."
4. Select "Test-ID 04: Calibration identification".

1. The Transmission Control Module (TCM) J217 identification will be displayed, e.g.: 09G27750 L 0301
2. End diagnosis and switch ignition off.
3. Replace mechatronic unit in transmission. --> «38 - AUTOMATIC TRANSMISSION - GEARS, HYDRAULIC CONTROLS»(ref-281381-S08686013262008031100000) .
4. Check identification of the new Transmission Control Module (TCM) J217 to ensure it matches the old Transmission Control Module (TCM) J217.

1. Code Transmission Control Module (TCM) J217. --> «Diagnostic mode 9: Vehicle information»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__diagnostic-mode-9-vehicle-information) .
2. Generate readiness code. --> «Readiness code, generating»(/audi/a6/6-2004-2008/remont/cooling-fan/#42l-v8-5v-generic-scan-tool-engine-codes-bnk__readiness-code-generating) .

Voltage supply for the Transmission Control Module (TCM) J217 , checking

Note. The Transmission Control Module (TCM) J217 is a component of the mechatronic unit in the transmission and cannot be replaced separately.

Special tools, testers and auxiliary items required

1. Multimeter V.A.G 1526 A or equivalent.
2. Wiring diagrams.

Requirements

1. The fuses for the transmission electronics OK..
2. The battery voltage must be at least 12.5 volts.
3. The Ground (GND) connections at the transmission OK.
4. The parking brake engaged.

1. The selector lever of automatic transmission in position "P".
2. All electrical consumers switched off.
3. The ignition switched off.

Test sequence

1. Release electrical connector in direction of - arrow - and remove it from the Transmission Control Module (TCM) J217.

Observe safety precautions.

1. Check electrical harness connector for contact corrosion and ingress of water.

If electrical harness connector is not OK

1. Repair malfunction.

If electrical harness connector is OK

1. Check wiring according to the wiring diagram

If no malfunctions are found in wiring

1. Replace Mechatronic unit in transmission: --> «38 - AUTOMATIC TRANSMISSION - GEARS, HYDRAULIC CONTROLS»(ref-281381-S08686013262008031100000) .

Note. The Transmission Control Module (TCM) J217 is a component of the Mechatronic unit and cannot be replaced separately.

Final procedures

1. Check DTC memory..
2. If necessary, erase DTC memory of Transmission Control Module (TCM) J217..
3. Generate readiness code..

On Board Diagnostic (OBD) characteristics

On Board Diagnostic (OBD), characteristics

The Engine Control Module (ECM) J623 is equipped with DTC memory.

Malfunction recognition

If malfunctions occur at the emission relevant systems or components, they are stored in the DTC memory with a description of the malfunction type.

The Engine Control Module (ECM) J623 differentiates between different DTCs after evaluating the information.

The stored malfunctions can be checked with a standard diagnostic tester. --> Diagnostic tester, connecting .

If the Engine Control Module (ECM) J623 recognizes malfunctions that lead to a worsening of emissions values, it indicates them by lighting the Malfunction Indicator Lamp (MIL) K83 in instrument cluster. --> Malfunction Indicator Lamp (MIL) K83 in instrument cluster .

Electronic throttle malfunctions are also indicated by Electronic Power Control (EPC) Warning Lamp K132 in the instrument cluster. --> Electronic Power Control (EPC) Warning Lamp K132 in instrument cluster .

When disconnecting electrical harness connectors from the Engine Control Module (ECM) J623 or when disconnecting the battery, all adaptation values in the ECM are erased. The DTC memory content will remain intact. however, after reconnecting the electrical harness connectors or battery, the following work steps must be performed in the mentioned sequence

1. Check DTC memory..
2. If necessary, erase DTC memory..
3. If DTC memory was erased, generate readiness code..

1. End diagnosis and switch ignition off.