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Exhaust System, Emission Controls, Generic Scan Tool (1.8l 5v Turbo, Amb) Audi A4 B6

Exhaust 14 illustrations ~4413 words

Exhaust system components, removing and installing

Note. Always replace gaskets and self-locking nuts. After exhaust system repairs, make sure exhaust system is not under stress and has sufficient clearance from the body. If necessary, loosen clamps and align mufflers and exhaust pipes so that there is adequate distance to vehicle body, and weight is evenly distributed among the exhaust mounts. Decoupling element in front exhaust pipe must not be bent more than 10°, otherwise it may be damaged.

Exhaust system for vehicles with Front Wheel Drive (FWD) - Component overview

Note. The following list refers to (Scheme 27).

  1. Turbocharger
  2. Seal replace
  3. Heated Oxygen Sensor (HO2S) -G39- (before catalytic converter) Bank 1, sensor 1 Removing and installing. See «OXYGEN SENSORS, REMOVING AND INSTALLING»(/audi/a4/b6-2000-2006/remont/exhaust/#exhaust-system-emission-controls-generic-scan-tool-18l-5v-turbo-amb) . The threads of new oxygen sensors are coated with assembly paste; the paste must not get into slots of oxygen sensor body When re-using the old oxygen sensor, grease the threads with hot bolt paste; the paste must not get into slots of oxygen sensor body. Tighten to 55 N.m
  4. Oxygen Sensor (O2S) Behind Three Way Catalytic Converter (TWC) -G130- with Oxygen Sensor (O2S) Heater 1 -Z29- Bank 1, sensor 2 Removing and installing. See «OXYGEN SENSORS, REMOVING AND INSTALLING»(/audi/a4/b6-2000-2006/remont/exhaust/#exhaust-system-emission-controls-generic-scan-tool-18l-5v-turbo-amb) . The threads of new oxygen sensors are coated with assembly paste; the paste must not get into slots of oxygen sensor body When re-using the old oxygen sensor, grease the threads with hot bolt paste; the paste must not get into slots of oxygen sensor body. Tighten to 55 N.m
  5. Catalytic converter Protect from hit- and impact stress Install exhaust system free of stress. See «ALIGN EXHAUST SYSTEM TENSION-FREE (VEHICLES WITH FRONT WHEEL DRIVE)»(/audi/a4/b6-2000-2006/remont/exhaust/#exhaust-system-emission-controls-generic-scan-tool-18l-5v-turbo-amb__align-exhaust-system-tension-free-vehicles-with) . Removing and installing. See «CATALYTIC CONVERTER, REMOVING AND INSTALLING»(/audi/a4/b6-2000-2006/remont/exhaust/#exhaust-system-emission-controls-generic-scan-tool-18l-5v-turbo-amb) .
  6. Seal replace
  7. 25 N.m
  8. Front exhaust pipe with decoupling element Decoupling element must not be kinked more than 10°, otherwise it may be damaged
  9. Front clamping sleeve Before tightening, align exhaust system is tension-free. See «ALIGN EXHAUST SYSTEM TENSION-FREE (VEHICLES WITH FRONT WHEEL DRIVE)»(/audi/a4/b6-2000-2006/remont/exhaust/#exhaust-system-emission-controls-generic-scan-tool-18l-5v-turbo-amb__align-exhaust-system-tension-free-vehicles-with) . Installation position. See «INSTALLED POSITION OF FRONT CLAMPING SLEEVE»(/audi/a4/b6-2000-2006/remont/exhaust/#exhaust-system-emission-controls-generic-scan-tool-18l-5v-turbo-amb__installed-position-of-front-clamping-sleeve) . Tighten bolts evenly
  10. 40 N.m
  11. Spacer sleeve
  12. Buffer
  13. Strap
  14. Washer
  15. 30 N.m
  16. Rear muffler for left side of vehicle Factory-installed with center muffler as one unit. If repair is necessary, replace separately Install exhaust system free of stress. See «ALIGN EXHAUST SYSTEM TENSION-FREE (VEHICLES WITH FRONT WHEEL DRIVE)»(/audi/a4/b6-2000-2006/remont/exhaust/#exhaust-system-emission-controls-generic-scan-tool-18l-5v-turbo-amb__align-exhaust-system-tension-free-vehicles-with) .
  17. Suspended mount Replace if damaged
  18. 25 N.m
  19. Rear muffler for right side of vehicle Factory-installed with center muffler as one unit. If repair is necessary, replace separately Install exhaust system free of stress. See «ALIGN EXHAUST SYSTEM TENSION-FREE (VEHICLES WITH FRONT WHEEL DRIVE)»(/audi/a4/b6-2000-2006/remont/exhaust/#exhaust-system-emission-controls-generic-scan-tool-18l-5v-turbo-amb__align-exhaust-system-tension-free-vehicles-with) .
  20. 40 N.m
  21. Rear clamping sleeve 2x Used when center or rear muffler is replaced separately. Before tightening, align exhaust system is tension-free. See «ALIGN EXHAUST SYSTEM TENSION-FREE (VEHICLES WITH FRONT WHEEL DRIVE)»(/audi/a4/b6-2000-2006/remont/exhaust/#exhaust-system-emission-controls-generic-scan-tool-18l-5v-turbo-amb__align-exhaust-system-tension-free-vehicles-with) . Installed position. See «INSTALLED POSITION OF REAR CLAMPING SLEEVES»(/audi/a4/b6-2000-2006/remont/exhaust/#exhaust-system-emission-controls-generic-scan-tool-18l-5v-turbo-amb__installed-position-of-rear-clamping-sleeves) . Tighten bolts evenly
  22. Center muffler Factory-installed with rear muffler as one unit. If repair is necessary, replace separately Install exhaust system free of stress. See «ALIGN EXHAUST SYSTEM TENSION-FREE (VEHICLES WITH FRONT WHEEL DRIVE)»(/audi/a4/b6-2000-2006/remont/exhaust/#exhaust-system-emission-controls-generic-scan-tool-18l-5v-turbo-amb__align-exhaust-system-tension-free-vehicles-with) .
  23. 25 N.m
  24. Suspended mount Replace if damaged
  25. Bolt
  26. Washer
  27. Compression spring
  28. Spacer sleeve
  29. 25 N.m
  30. 40 N.m replace

Exhaust system for vehicles with All Wheel Drive (AWD) - Component overview

Note. The following list refers to (Scheme 28).

  1. Turbocharger
  2. Seal replace
  3. Heated Oxygen Sensor (HO2S) -G39- (before catalytic converter) Bank 1, sensor 1 Removing and installing. See «OXYGEN SENSORS, REMOVING AND INSTALLING»(/audi/a4/b6-2000-2006/remont/exhaust/#exhaust-system-emission-controls-generic-scan-tool-18l-5v-turbo-amb) . The threads of new oxygen sensors are coated with assembly paste; the paste must not get into slots of oxygen sensor body When re-using the old oxygen sensor, grease the threads with hot bolt paste; the paste must not get into slots of oxygen sensor body. Tighten to 55 N.m
  4. Oxygen Sensor (O2S) Behind Three Way Catalytic Converter (TWC) -G130- with Oxygen Sensor (O2S) Heater 1 -Z29- Bank 1, sensor 2 Removing and installing. See «OXYGEN SENSORS, REMOVING AND INSTALLING»(/audi/a4/b6-2000-2006/remont/exhaust/#exhaust-system-emission-controls-generic-scan-tool-18l-5v-turbo-amb) . The threads of new oxygen sensors are coated with assembly paste; the paste must not get into slots of oxygen sensor body When re-using the old oxygen sensor, grease the threads with hot bolt paste; the paste must not get into slots of oxygen sensor body. Tighten to 55 N.m
  5. Catalytic converter Protect from hit- and impact stress Install exhaust system free of stress. See «ALIGN EXHAUST SYSTEM TENSION-FREE (VEHICLES WITH FRONT WHEEL DRIVE)»(/audi/a4/b6-2000-2006/remont/exhaust/#exhaust-system-emission-controls-generic-scan-tool-18l-5v-turbo-amb__align-exhaust-system-tension-free-vehicles-with) . Removing and installing. See «CATALYTIC CONVERTER, REMOVING AND INSTALLING»(/audi/a4/b6-2000-2006/remont/exhaust/#exhaust-system-emission-controls-generic-scan-tool-18l-5v-turbo-amb) .
  6. Seal replace
  7. 25 N.m
  8. Front exhaust pipe with decoupling element Decoupling element must not be kinked more than 10°, otherwise it may be damaged
  9. Front clamping sleeve Before tightening, align exhaust system is tension-free. See «ALIGN EXHAUST SYSTEM TENSION-FREE (VEHICLES WITH FRONT WHEEL DRIVE)»(/audi/a4/b6-2000-2006/remont/exhaust/#exhaust-system-emission-controls-generic-scan-tool-18l-5v-turbo-amb__align-exhaust-system-tension-free-vehicles-with) . Installation position. See «INSTALLED POSITION OF FRONT CLAMPING SLEEVE»(/audi/a4/b6-2000-2006/remont/exhaust/#exhaust-system-emission-controls-generic-scan-tool-18l-5v-turbo-amb__installed-position-of-front-clamping-sleeve) . Tighten bolts evenly
  10. 40 N.m
  11. Spacer sleeve
  12. Buffer
  13. Strap
  14. Washer
  15. 30 N.m
  16. Rear muffler for left side of vehicle Factory-installed with center muffler as one unit. If repair is necessary, replace separately Install exhaust system free of stress. See «ALIGN EXHAUST SYSTEM TENSION-FREE (VEHICLES WITH FRONT WHEEL DRIVE)»(/audi/a4/b6-2000-2006/remont/exhaust/#exhaust-system-emission-controls-generic-scan-tool-18l-5v-turbo-amb__align-exhaust-system-tension-free-vehicles-with) .
  17. Suspended mount Replace if damaged
  18. 25 N.m
  19. Rear muffler for right side of vehicle Factory-installed with center muffler as one unit. If repair is necessary, replace separately Install exhaust system free of stress. See «ALIGN EXHAUST SYSTEM TENSION-FREE (VEHICLES WITH FRONT WHEEL DRIVE)»(/audi/a4/b6-2000-2006/remont/exhaust/#exhaust-system-emission-controls-generic-scan-tool-18l-5v-turbo-amb__align-exhaust-system-tension-free-vehicles-with) .
  20. 40 N.m
  21. Rear clamping sleeve 2x Used when center or rear muffler is replaced separately. Before tightening, align exhaust system is tension-free. See «ALIGN EXHAUST SYSTEM TENSION-FREE (VEHICLES WITH FRONT WHEEL DRIVE)»(/audi/a4/b6-2000-2006/remont/exhaust/#exhaust-system-emission-controls-generic-scan-tool-18l-5v-turbo-amb__align-exhaust-system-tension-free-vehicles-with) . Installed position. See «INSTALLED POSITION OF REAR CLAMPING SLEEVES»(/audi/a4/b6-2000-2006/remont/exhaust/#exhaust-system-emission-controls-generic-scan-tool-18l-5v-turbo-amb__installed-position-of-rear-clamping-sleeves) . Tighten bolts evenly
  22. Center muffler Factory-installed with rear muffler as one unit. If repair is necessary, replace separately Install exhaust system free of stress. See «ALIGN EXHAUST SYSTEM TENSION-FREE (VEHICLES WITH FRONT WHEEL DRIVE)»(/audi/a4/b6-2000-2006/remont/exhaust/#exhaust-system-emission-controls-generic-scan-tool-18l-5v-turbo-amb__align-exhaust-system-tension-free-vehicles-with) .
  23. 25 N.m
  24. Suspended mount Replace if damaged
  25. Bolt
  26. Washer
  27. Compression spring
  28. Strap
  29. Spacer sleeve
  30. 25 N.m
  31. 40 N.m replace

Installed position of front clamping sleeve

  1. When installing clamping sleeve, tighten bolt only as needed to align bolt ends with lower edge of clamping sleeve. Screw connections face each other

Installed position of rear clamping sleeves

  1. Install double clamps so that the bolt ends do not project beyond lower edge of double clamp. Threaded connections point outward

Catalytic converter, checking

  1. Perform the test in "Mode 6: Check test results of components that are not continuously monitored", as described under "Test-ID 01: Check catalytic converter". See «TEST-ID 01: CATALYTIC CONVERTER»(/audi/a4/b6-2000-2006/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb) .
  2. Replace catalytic converter. See «CATALYTIC CONVERTER, REMOVING AND INSTALLING»(/audi/a4/b6-2000-2006/remont/exhaust/#exhaust-system-emission-controls-generic-scan-tool-18l-5v-turbo-amb) .

Recommended special tools and equipment

  1. 3337 wrench, 7-piece set

Removing

  1. Disconnect 6-pin harness connector (black) -5- to Heated Oxygen Sensor (HO2S) -G39- before catalytic converter and 4-pin harness connector (brown) -2- to Oxygen Sensor (O2S) Behind Three Way Catalytic Converter (TWC) -G130-. (Scheme 31)

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

Scheme 27

Scheme 27
Scheme 27
  1. Expose electrical wire to oxygen sensor.
  2. Unscrew oxygen sensor e.g. using special tool 3337.

Installing

Installation is the reverse of removal, noting the following

Note. The threads of new oxygen sensors are coated with assembly paste; the paste must not get into slots of oxygen sensor body. When re-using the old oxygen sensor, grease the threads with hot bolt paste; the paste must not get into slots of oxygen sensor body. Wires of oxygen sensors must always be secured in the same position when installing so that contact with the exhaust pipe is avoided.

Tightening torque

ComponentN.m
Oxygen sensor to catalytic converter55

TIGHTENING TORQUE: OXYGEN SENSOR

  1. Disconnect 6-pin harness connector (black) -5- to Heated Oxygen Sensor (HO2S) -G39- before catalytic converter and 4-pin harness connector (brown) -2- to Oxygen Sensor (O2S) Behind Three Way Catalytic Converter (TWC) -G130-.

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

Scheme 28

Scheme 28
Scheme 28
  1. Remove air filter cover (arrow).
  2. Remove bolts (arrows). (Scheme 36)
  3. Disengage Evaporative Emission (EVAP) Canister Purge Regulator Valve -N80- (item 1) at air guide -2- and remove air guide.
  4. Disconnect electrical harness connectors at: - Evaporative Emission (EVAP) Canister Purge Regulator Valve -N80-. (Scheme 37) - Mass Air Flow (MAF) Sensor -G70- - Wastegate Bypass Regulator Valve -N75
  5. Disconnect hoses -4- to... -7-.
  6. Disconnect hose to Secondary Air Injection (AIR) pump.
  7. Expose electrical cables.
  8. Unbolt air filter housing -8- and remove, to do so, disconnect cable to Evaporative Emission (EVAP) Canister Purge Regulator Valve -N80- on underside of intake air hose.
  9. Unbolt bolts which can be reached from the top between front exhaust pipe and catalytic converter.
  10. Remove heat shield above right drive axle, to do so, remove bolts (arrows).
  11. Disconnect exhaust system at front double clamp (arrows).
  12. Remove bolts (lower arrows) front exhaust pipe/catalytic converter.
  13. Unbolt bracket (upper arrow) for exhaust system on transmission. NOTE: Decoupling element in front exhaust pipe must not be bent more than 10°, otherwise it may be damaged.
  14. Remove front exhaust pipe.
  15. Remove nuts (arrows) for turbocharger/catalytic converter.
  16. Take catalytic converter up and out.

Installation is the reverse of removal, noting the following

Note. All cable ties opened or cut during engine removal must be reinstalled at the same locations during installation. Replace gaskets and self-locking nuts. Wires of oxygen sensors must always be secured in the same position when installing so that contact with the exhaust pipe is avoided. Install exhaust system free of stress. See ALIGN EXHAUST SYSTEM TENSION-FREE (VEHICLES WITH FRONT WHEEL DRIVE) and ALIGN EXHAUST SYSTEM TENSION-FREE (VEHICLES WITH ALL WHEEL DRIVE) .

Tightening torques

ComponentN.m
Catalytic converter to turbocharger40
Front exhaust pipe to catalytic converter25
Front exhaust pipe to transmission mount25
Drive axle protection to transmission23
Hose clamps for air guide hoses3,5

TIGHTENING TORQUE: CATALYTIC CONVERTER

Align exhaust system tension-free (vehicles with front wheel drive)

Note. Align exhaust system when cold.

  1. Loosen bolts (arrows) of front clamping sleeve. Vehicles without clamp between center and rear muffler
  2. Push exhaust system far enough forward (arrow) so that the pretension at the retaining loop at center muffler a = 5 to 9 mm.
  3. Tighten double clamp bolts uniformly to 40 N.m.
  4. Align end pipes. See «TAILPIPES, ALIGNING»(/audi/a4/b6-2000-2006/remont/exhaust/#exhaust-system-emission-controls-generic-scan-tool-18l-5v-turbo-amb__tailpipes-aligning) . Vehicles with clamp between center and rear muffler

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

  1. Loosen double clamp mounting bolts at front. See item 9 in «EXHAUST SYSTEM FOR VEHICLES WITH FRONT WHEEL DRIVE (FWD) - COMPONENT OVERVIEW»(/audi/a4/b6-2000-2006/remont/exhaust/#exhaust-system-emission-controls-generic-scan-tool-18l-5v-turbo-amb__exhaust-system-for-vehicles-with-front) . At rear see item 21 in «EXHAUST SYSTEM FOR VEHICLES WITH FRONT WHEEL DRIVE (FWD) - COMPONENT OVERVIEW»(/audi/a4/b6-2000-2006/remont/exhaust/#exhaust-system-emission-controls-generic-scan-tool-18l-5v-turbo-amb__exhaust-system-for-vehicles-with-front) .
  2. Push front part of exhaust system far enough forward (arrow) so that the pre-tension at the retaining loop at center muffler a = 5 to 9 mm.
  3. Tighten front double clamp mounting bolts evenly to 40 N.m. See item 9 in «EXHAUST SYSTEM FOR VEHICLES WITH FRONT WHEEL DRIVE (FWD) - COMPONENT OVERVIEW»(/audi/a4/b6-2000-2006/remont/exhaust/#exhaust-system-emission-controls-generic-scan-tool-18l-5v-turbo-amb__exhaust-system-for-vehicles-with-front) .
  4. Push rear part of exhaust system far enough forward (arrow) so that the pre-tension at rear retaining loops at rear muffler a = 7 to 11 mm.
  5. Align rear muffler horizontally.
  6. Tighten rear double clamp mounting bolts evenly to 40 N.m. See item 21 in «EXHAUST SYSTEM FOR VEHICLES WITH FRONT WHEEL DRIVE (FWD) - COMPONENT OVERVIEW»(/audi/a4/b6-2000-2006/remont/exhaust/#exhaust-system-emission-controls-generic-scan-tool-18l-5v-turbo-amb__exhaust-system-for-vehicles-with-front) .
  7. Align end pipes. See «TAILPIPES, ALIGNING»(/audi/a4/b6-2000-2006/remont/exhaust/#exhaust-system-emission-controls-generic-scan-tool-18l-5v-turbo-amb__tailpipes-aligning) .

Align exhaust system tension-free (vehicles with all wheel drive)

Note. Align exhaust system when cold.

  1. Loosen bolts (arrows) of front clamping sleeve. Vehicles without clamp between center and rear muffler
  2. Push exhaust system far enough forward (arrow) so that the pretension at the right retaining loop at center muffler a = 5 to 9 mm.
  3. Tighten double clamp bolts uniformly to 40 N.m.
  4. Align end pipes. See «TAILPIPES, ALIGNING»(/audi/a4/b6-2000-2006/remont/exhaust/#exhaust-system-emission-controls-generic-scan-tool-18l-5v-turbo-amb__tailpipes-aligning) . Vehicles with clamp between center and rear muffler

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

  1. Loosen double clamp mounting bolts. See item 9 in «EXHAUST SYSTEM FOR VEHICLES WITH ALL WHEEL DRIVE (AWD) - COMPONENT OVERVIEW»(/audi/a4/b6-2000-2006/remont/exhaust/#exhaust-system-emission-controls-generic-scan-tool-18l-5v-turbo-amb__exhaust-system-for-vehicles-with-all) and item 21 in «EXHAUST SYSTEM FOR VEHICLES WITH ALL WHEEL DRIVE (AWD) - COMPONENT OVERVIEW»(/audi/a4/b6-2000-2006/remont/exhaust/#exhaust-system-emission-controls-generic-scan-tool-18l-5v-turbo-amb__exhaust-system-for-vehicles-with-all) .
  2. Push front part of exhaust system far enough forward (arrow) so that the pre-tension at the retaining loop at center muffler a = 5 to 9 mm.
  3. Tighten front double clamp mounting bolts evenly to 40 N.m. See item 9 in «EXHAUST SYSTEM FOR VEHICLES WITH ALL WHEEL DRIVE (AWD) - COMPONENT OVERVIEW»(/audi/a4/b6-2000-2006/remont/exhaust/#exhaust-system-emission-controls-generic-scan-tool-18l-5v-turbo-amb__exhaust-system-for-vehicles-with-all) .
  4. Push rear part of exhaust system far enough forward (arrow) so that the pre-tension at rear retaining loops at rear muffler a = 7 to 11 mm.
  5. Align rear muffler horizontally.
  6. Tighten rear double clamp mounting bolts evenly to 40 N.m. See item 21 in «EXHAUST SYSTEM FOR VEHICLES WITH ALL WHEEL DRIVE (AWD) - COMPONENT OVERVIEW»(/audi/a4/b6-2000-2006/remont/exhaust/#exhaust-system-emission-controls-generic-scan-tool-18l-5v-turbo-amb__exhaust-system-for-vehicles-with-all) .
  7. Align end pipes. See «TAILPIPES, ALIGNING»(/audi/a4/b6-2000-2006/remont/exhaust/#exhaust-system-emission-controls-generic-scan-tool-18l-5v-turbo-amb__tailpipes-aligning) .

Tailpipes, aligning

  1. Check distance of end pipes at left and right to bumper: Dimension x left = dimension x right
  2. Loosen nut (arrow) of brace between exhaust pipes.
  3. Change the distance of the rear mufflers to each other.
  4. Tighten nut to 23 N.m.
  5. Check distances -y- and -z- of end pipes to bumper: Dimension y = greater than 20 mm Dimension z = 9 to 14 mm
  6. If necessary, check whether the exhaust system is installed tension-free. See «ALIGN EXHAUST SYSTEM TENSION-FREE (VEHICLES WITH FRONT WHEEL DRIVE)»(/audi/a4/b6-2000-2006/remont/exhaust/#exhaust-system-emission-controls-generic-scan-tool-18l-5v-turbo-amb__align-exhaust-system-tension-free-vehicles-with) or «ALIGN EXHAUST SYSTEM TENSION-FREE (VEHICLES WITH ALL WHEEL DRIVE)»(/audi/a4/b6-2000-2006/remont/exhaust/#exhaust-system-emission-controls-generic-scan-tool-18l-5v-turbo-amb__align-exhaust-system-tension-free-vehicles-with) .

Exhaust system, checking for leaks

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

Secondary air system

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

Principle

Due to over-enrichment of the mixture during the cold start phase, there is an increased amount of carbon monoxide in the exhaust.

Secondary Air Injection (AIR) improves secondary oxidation in the catalytic converter and therefore reduces emissions. The heat produced by secondary oxidation greatly reduces start-up time for the catalytic converter, therefore improving exhaust quality during the cold start phase significantly.

Scheme 29

Scheme 29: Principle
Scheme 29: Principle

Function

  1. In the cold start phase, the ECM -6- activates the secondary air pump -1- via the relay for secondary air pump -5-. Air reaches the combination valve for Secondary Air Injection (AIR) system -3-.
  2. The Secondary Air Injection (AIR) valve -8- is activated in parallel, which allows the vacuum to reach the combination valve for Secondary Air Injection (AIR) -3-. The combination valve for Secondary Air Injection (AIR) thereby opens the path for secondary air to the exhaust channels of the cylinder head.

Component overview

Note. The following list refers to see scheme 29.

  1. Secondary Air Injection (AIR) Pump Motor -V101- Component location. See «COMPONENT LOCATION OF SECONDARY AIR INJECTION (AIR) PUMP MOTOR -V101»(/audi/a4/b6-2000-2006/remont/exhaust/#exhaust-system-emission-controls-generic-scan-tool-18l-5v-turbo-amb__component-location-of-secondary-air-injection). Checking. See «CHECK VOLTAGE SUPPLY OF THE SECONDARY AIR INJECTION (AIR) PUMP MOTOR»(/audi/a4/b6-2000-2006/remont/exhaust/#exhaust-system-emission-controls-generic-scan-tool-18l-5v-turbo-amb).
  2. Air filter housing
  3. Combination valve for Secondary Air Injection (AIR) system Component location. See «COMBINATION VALVE FOR SECONDARY AIR INJECTION (AIR) SYSTEM»(/audi/a4/b6-2000-2006/remont/exhaust/#exhaust-system-emission-controls-generic-scan-tool-18l-5v-turbo-amb__combination-valve-for-secondary-air-injection). Checking. See «COMBINATION VALVE FOR SECONDARY AIR INJECTION (AIR) SYSTEM, CHECKING FUNCTION AND FOR PROPER SEAL»(/audi/a4/b6-2000-2006/remont/exhaust/#exhaust-system-emission-controls-generic-scan-tool-18l-5v-turbo-amb).
  4. Check-valve Installation position (light/dark side): Arrow points in direction of flow see scheme 29
  5. Secondary Air Injection (AIR) Pump Relay -J299- Component location. See «COMPONENT LOCATION OF SECONDARY AIR INJECTION (AIR) PUMP RELAY -J299»(/audi/a4/b6-2000-2006/remont/exhaust/#exhaust-system-emission-controls-generic-scan-tool-18l-5v-turbo-amb__component-location-of-secondary-air-injection). Checking. See «SECONDARY AIR INJECTION (AIR) PUMP RELAY -J299- AND ACTIVATION, CHECKING»(/audi/a4/b6-2000-2006/remont/exhaust/#exhaust-system-emission-controls-generic-scan-tool-18l-5v-turbo-amb).
  6. Motronic Engine Control Module (ECM) -J220
  7. Vacuum reservoir Component location: Under wheel housing liner in front left wheel housing
  8. Secondary Air Injection (AIR) solenoid valve -N112- Component location. See «COMPONENT LOCATION OF SECONDARY AIR INJECTION (AIR) SOLENOID VALVE -N112- AND RECIRCULATING VALVE FOR TURBOCHARGER -N249»(/audi/a4/b6-2000-2006/remont/exhaust/#exhaust-system-emission-controls-generic-scan-tool-18l-5v-turbo-amb__component-location-of-secondary-air-injection). Checking. See «SECONDARY AIR INJECTION (AIR) SOLENOID VALVE -N112- CHECKING»(/audi/a4/b6-2000-2006/remont/exhaust/#exhaust-system-emission-controls-generic-scan-tool-18l-5v-turbo-amb).
  9. Cylinder head

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

  1. Component location: Below intake manifold - Recirculating valve for turbocharger -N249- - Secondary Air Injection (AIR) solenoid valve -N112- NOTE: Illustration depicts intake manifold removed, from below.

Scheme 30

Scheme 30
Scheme 30

Component location of Secondary Air Injection (AIR) Pump Motor -V101

  1. At front right in engine compartment below air filter housing

Scheme 31

Scheme 31
Scheme 31

Component location of Secondary Air Injection (AIR) Pump Relay -J299

  1. In E-box, plenum chamber 2 - Secondary Air Injection (AIR) Pump Relay -J299- B - Fuse S130 for Secondary Air Injection (AIR) pump

Combination valve for Secondary Air Injection (AIR) system

  1. rear right on cylinder head

Scheme 32

Scheme 32
Scheme 32

Removing and installing combination valve for Secondary Air Injection (AIR) system

  1. Remove engine cover (arrows).
  2. Disconnect harness connector at Engine Coolant Temperature (ECT) Sensor -G2-/-G62- (arrow).
  3. Expose electrical wiring harness on bulkhead.
  4. Disconnect vacuum hose (arrow) at combination valve.
  5. Unbolt 4 bolts at combination valve and remove combination valve.

Installation is the reverse of removal, noting the following

Note. Replace gaskets.

ComponentN.m
Combination valve for Secondary Air Injection (AIR) system at cylinder head10
Secondary Air Injection (AIR) line to cylinder head cover10
Secondary air injection line to combination valve for secondary air injection10

TIGHTENING TORQUE: COMBINATION VALVE FOR SECONDARY AIR INJECTION (AIR) SYSTEM

Secondary Air Injection (AIR) system, checking for proper seal

  1. Check the connection pipes and hoses between Secondary Air Injection (AIR) pump motor and combination valve for proper seal component overview. See «COMPONENT OVERVIEW»(/audi/a4/b6-2000-2006/remont/exhaust/#exhaust-system-emission-controls-generic-scan-tool-18l-5v-turbo-amb__component-overview) .
  2. Check hoses and hose connections for secure seating.
  3. Check combination valve for Secondary Air Injection (AIR) system for proper seal. See «COMBINATION VALVE FOR SECONDARY AIR INJECTION (AIR) SYSTEM, CHECKING FUNCTION AND FOR PROPER SEAL»(/audi/a4/b6-2000-2006/remont/exhaust/#exhaust-system-emission-controls-generic-scan-tool-18l-5v-turbo-amb) .

Final procedures

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

  1. Check DTC memory. See «MODE 3: CHECK DTC MEMORY»(/audi/a4/b6-2000-2006/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb__mode-3-check-dtc-memory) .
  2. If necessary, erase DTC memory. See «MODE 4: RESET/ERASE DIAGNOSTIC DATA»(/audi/a4/b6-2000-2006/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb__mode-4-reseterase-diagnostic-data) .
  3. Generate readiness code. See «READINESS CODE, GENERATING»(/audi/a4/b6-2000-2006/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb) . End diagnosis and switch ignition off.
  1. VAG1390 Hand Vacuum Pump

Test requirements

  1. No leaks in vacuum lines or hose connections.
  2. Vacuum lines not clog

Test sequence

  1. Remove engine cover (arrows).

Scheme 33

Scheme 33
Scheme 33
  1. Disconnect vacuum hose (arrow) at combination valve.
  2. Connect hand vacuum pump, e.g. V.A.G 1390, to vacuum hose of combination valve.
  3. Remove bolts or quick-release screws -1- and -2- and remove front noise insulation.
  4. Disconnect hose (arrow) at tube to combination valve for Secondary Air Injection (AIR) system.
  5. Connect assisting hose to tube and blow into tube with light pressure (do not use compressed air). Combination valve must be closed, it must not be possible to blow through hose
  6. Operate hand vacuum pump. Combination valve must open, it must be possible to blow through
  7. Replace combination valve. See «REMOVING AND INSTALLING COMBINATION VALVE FOR SECONDARY AIR INJECTION (AIR) SYSTEM»(/audi/a4/b6-2000-2006/remont/exhaust/#exhaust-system-emission-controls-generic-scan-tool-18l-5v-turbo-amb__removing-and-installing-combination-valve-for) .

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

  1. Check DTC memory. See «MODE 3: CHECK DTC MEMORY»(/audi/a4/b6-2000-2006/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb__mode-3-check-dtc-memory) .
  2. If necessary, erase DTC memory. See «MODE 4: RESET/ERASE DIAGNOSTIC DATA»(/audi/a4/b6-2000-2006/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb__mode-4-reseterase-diagnostic-data) .
  3. Generate readiness code. See «READINESS CODE, GENERATING»(/audi/a4/b6-2000-2006/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb) . End diagnosis and switch ignition off.
  1. VAG1526A hand multimeter
  2. VAG1594A connector test kit
  3. VAG1598/31 test box
  1. Fuse for Secondary Air Injection (AIR) solenoid valve OK See appropriate System Wiring Diagram article.
  2. Fuel Pump (FP) Relay OK; checking. See «FUEL PUMP (FP) RELAY -J17- AND ACTIVATION, CHECKING»(/audi/a4/b6-2000-2006/remont/fuel-system/#multiport-fuel-injection-mfi-generic-scan-tool-18l-5v-turbo-amb__fuel-pump-fp-relay-j17-and) .
  3. Ignition switched off.

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

Work procedure

  1. Disconnect electrical harness connector from Secondary Air Injection (AIR) Solenoid Valve -N112- (item 2).

Checking internal resistance

  1. Connect multimeter at valve for resistance measurement. Specified value: 27 ... 30ohm
  2. Replace Secondary Air Injection (AIR) Solenoid Valve -N112-.

If specified value is obtained

Checking voltage supply

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

If there is no voltage

  1. Connect multimeter for voltage measurement as follows: SECONDARY AIR INJECTION SOLENOID VALVE: TERMINAL 1 MEASUREMENT Harness connector Terminal Measure to 1 Engine Ground (GND)
  2. Operate starter briefly. Specified value: approx. battery voltage
  3. Switch ignition off.
  4. Check wire connection from harness connector terminal 1 to Fuel Pump (FP) Relay -J17- via fuse for open circuit according to wiring diagram. Specified value: Wire resistance max 1.5 ohm
  5. If necessary, repair wire connection.

If voltage supply is OK

Scheme 34

Scheme 34: Check Ground (GND) activation
Scheme 34: Check Ground (GND) activation

Scheme 35

Scheme 35
Scheme 35
  1. Connect multimeter for voltage measurement as follows: SECONDARY AIR INJECTION SOLENOID VALVE: TERMINAL 2 MEASUREMENT Harness connector Terminal Measure to 2 B+
  2. Operate starter briefly. Specified value: approx. battery voltage
  3. Switch ignition off.
  4. Connect test box to wiring harness of Engine Control Module (ECM). See «TEST BOX, CONNECTING FOR WIRING AND COMPONENT TEST»(/audi/a4/b6-2000-2006/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb) ; ECM is not connected.
  5. Check the following wire connection for open circuit according to wiring diagram: SECONDARY AIR INJECTION SOLENOID VALVE: TERMINAL 2 & SOCKET 9 Harness connector Terminal Test box Socket 2 9 Specified value: Wire resistance max 1.5 ohm
  6. Also check the wire for short circuit to B+ and Ground (GND). Specified value: INFINITY ohm (no continuity)
  7. If necessary, repair wire connection.
  8. Replace Engine Control Module (ECM).

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

  1. Check DTC memory. See «MODE 3: CHECK DTC MEMORY»(/audi/a4/b6-2000-2006/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb__mode-3-check-dtc-memory) .
  2. If necessary, erase DTC memory. See «MODE 4: RESET/ERASE DIAGNOSTIC DATA»(/audi/a4/b6-2000-2006/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb__mode-4-reseterase-diagnostic-data) .
  3. Generate readiness code. See «READINESS CODE, GENERATING»(/audi/a4/b6-2000-2006/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb) . End diagnosis and switch ignition off.
  1. VAG1526A hand multimeter
  2. V.A.G 1527 B Voltage Tester
  3. VAG1594A connector test kit
  4. VAG1598/31 test box
  1. Battery voltage at least 12.5 V
  2. Fuse for secondary air pump -S130- (40 A) in E-Box, plenum chamber (position B) OK.
  3. Fuse S234 (in fuse holder, position 34) OK.
  4. Ignition switched off.
  1. Pull off rubber seal of plenum chamber cover in direction of arrow.
  2. Remove cover -1- toward front.
  3. Pry off both covers -3- using a screwdriver.
  4. Loosen hex-nuts -4- by several turns.
  5. Loosen wiper arm -2- from wiper axle by lightly tilting.
  6. Remove hex nuts completely and remove wiper arms.
  7. Disconnect securing clips -1- and remove cowl grill -5-.
  8. Remove cover for E-box, plenum chamber (arrows).
  9. Pry off Engine Control Module (ECM) retaining bracket (arrows) using a screwdriver and set control module aside.
  10. If installed, unclip Transmission Control Module (TCM) retaining bracket and set control module aside.
  11. Connect test box to wiring harness of Engine Control Module (ECM). See «TEST BOX, CONNECTING FOR WIRING AND COMPONENT TEST»(/audi/a4/b6-2000-2006/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb) ; ECM is not connected
  12. Using wires e.g. from connector test kit V.A.G 1594 A, bridge terminals 1 and 66 on test box.

Scheme 36

Scheme 36
Scheme 36
  1. Switch ignition on. Secondary Air Injection (AIR) Pump Relay -2- (in E-box, plenum chamber) must engage and Secondary Air Injection (AIR) Pump Motor -V101- must run
  1. Secondary Air Injection (AIR) Pump Motor runs: Check voltage supply of the Secondary Air Injection (AIR) pump relay. See «CHECKING VOLTAGE SUPPLY OF SECONDARY AIR INJECTION (AIR) PUMP RELAY»(/audi/a4/b6-2000-2006/remont/exhaust/#exhaust-system-emission-controls-generic-scan-tool-18l-5v-turbo-amb) . Check activation of the Secondary Air Injection (AIR) pump relay. See «CHECK ACTIVATION OF THE SECONDARY AIR INJECTION (AIR) PUMP RELAY»(/audi/a4/b6-2000-2006/remont/exhaust/#exhaust-system-emission-controls-generic-scan-tool-18l-5v-turbo-amb) .
  2. Secondary Air Injection (AIR) Pump Motor does not run: Check voltage supply of the Secondary Air Injection (AIR) pump motor. See «CHECK VOLTAGE SUPPLY OF THE SECONDARY AIR INJECTION (AIR) PUMP MOTOR»(/audi/a4/b6-2000-2006/remont/exhaust/#exhaust-system-emission-controls-generic-scan-tool-18l-5v-turbo-amb) .

Scheme 37

Scheme 37: Checking voltage supply of Secondary Air Injection (AIR) pump relay
Scheme 37: Checking voltage supply of Secondary Air Injection (AIR) pump relay

Scheme 38

Scheme 38
Scheme 38
  1. Remove Secondary Air Injection (AIR) pump relay -2-.
  2. Connect multimeter for voltage measurement as follows. SECONDARY AIR INJECTION PUMP RELAY: TERMINAL 8 MEASURE Relay carrier in E-box, plenum chamber, position 2 Terminal Measure to 8 Engine Ground (GND) Specified value: approx. battery voltage
  3. Check wire connection from B+ (terminal 30) via Fuse for secondary air pump -S130- to Secondary Air Injection (AIR) Pump Relay -J299- (in relay and fuse carrier in E-Box, plenum chamber, position 3) for open circuit according to wiring diagram. Specified value: Wire resistance max 1.5 ohm
  4. Connect multimeter for voltage measurement as follows. SECONDARY AIR INJECTION PUMP RELAY: TERMINAL 4 MEASURE Relay carrier in E-box, plenum chamber, position 2 Terminal Measure to 4 Engine Ground (GND)
  5. Operate starter briefly. Specified value: approx. battery voltage
  6. Switch ignition off.
  7. Check wire connection from Secondary Air Injection (AIR) pump relay -J299- (in 3-socket relay carrier in E-box, plenum chamber) via fuse S234 (in fuse holder, position 34) to Fuel Pump (FP) relay for open circuit according to wiring diagram. Specified value: Wire resistance max 1.5 ohm

Scheme 39

Scheme 39: Check activation of the Secondary Air Injection (AIR) pump relay
Scheme 39: Check activation of the Secondary Air Injection (AIR) pump relay
  1. Remove Secondary Air Injection (AIR) pump relay -2-.
  2. Connect test box to wiring harness of Engine Control Module (ECM). See «TEST BOX, CONNECTING FOR WIRING AND COMPONENT TEST»(/audi/a4/b6-2000-2006/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb) ; ECM is not connected.
  3. Check the following wire connection for open circuit according to wiring diagram: SECONDARY AIR INJECTION PUMP RELAY: TERMINAL 6 & SOCKET 46 Relay carrier in E-box, plenum chamber, position 2 Terminal Test box Socket 6 46 Specified value: Wire resistance max 1.5 ohm
  4. Also check the wire for short circuit to B+ and Ground (GND). Specified value: INFINITY ohm (no continuity)
  5. Replace Secondary Air Injection (AIR) pump relay -J299-.

Scheme 40

Scheme 40: Check voltage supply of the Secondary Air Injection (AIR) pump motor
Scheme 40: Check voltage supply of the Secondary Air Injection (AIR) pump motor
  1. Remove bolts or quick-release screws -1- and -2- and remove front noise insulation.
  2. Disconnect electrical harness connector at Secondary Air Injection (AIR) Pump Motor -V101- (arrow).
  3. Connect VAG1527B voltage tester between terminals 1 and 2
  4. Connect test box to wiring harness of Engine Control Module (ECM). See «TEST BOX, CONNECTING FOR WIRING AND COMPONENT TEST»(/audi/a4/b6-2000-2006/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb) ; ECM is not connected.
  5. Bridge terminals 1 and 46 at test box using wires e.g. from V.A.G 1594 A adapter test kit. LED must light up.
  6. Check wire connection from terminal 2 of harness connector to Secondary Air Injection (AIR) Pump Relay -J299- (in relay carrier in E-Box, plenum chamber, position 3) for open circuit according to wiring diagram.
  7. Check wire connection from terminal 1 of harness connector to Ground (GND) for open circuit according to wiring diagram. Specified value: Wire resistance max 1.5 ohm
  8. Replace Secondary Air Injection (AIR) pump motor -V101-.

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

  1. Check DTC memory. See «MODE 3: CHECK DTC MEMORY»(/audi/a4/b6-2000-2006/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb__mode-3-check-dtc-memory) .
  2. If necessary, erase DTC memory. See «MODE 4: RESET/ERASE DIAGNOSTIC DATA»(/audi/a4/b6-2000-2006/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb__mode-4-reseterase-diagnostic-data) .
  3. Generate readiness code. See «READINESS CODE, GENERATING»(/audi/a4/b6-2000-2006/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb) . End diagnosis and switch ignition off.

See also:
• TEST-ID 01: CATALYTIC CONVERTER
• MODE 3: CHECK DTC MEMORY
• MODE 4: RESET/ERASE DIAGNOSTIC DATA
• FUEL PUMP (FP) RELAY -J17- AND ACTIVATION, CHECKING
• OXYGEN SENSORS, REMOVING AND INSTALLING
• ALIGN EXHAUST SYSTEM TENSION-FREE (VEHICLES WITH FRONT WHEEL DRIVE)
• INSTALLED POSITION OF FRONT CLAMPING SLEEVE
• INSTALLED POSITION OF REAR CLAMPING SLEEVES
• TAILPIPES, ALIGNING
• EXHAUST SYSTEM FOR VEHICLES WITH FRONT WHEEL DRIVE (FWD) - COMPONENT OVERVIEW
• EXHAUST SYSTEM FOR VEHICLES WITH ALL WHEEL DRIVE (AWD) - COMPONENT OVERVIEW
• COMPONENT LOCATION OF SECONDARY AIR INJECTION (AIR) PUMP MOTOR -V101
• COMBINATION VALVE FOR SECONDARY AIR INJECTION (AIR) SYSTEM
• COMPONENT OVERVIEW
• REMOVING AND INSTALLING COMBINATION VALVE FOR SECONDARY AIR INJECTION (AIR) SYSTEM

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