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3.2l - Exhaust System, Emission Controls - Engine Code(s): Cbra (coupe) (as of 02.2007) Audi TT 8J

Exhaust 5 illustrations ~1795 words

EXHAUST SYSTEM COMPONENTS, REMOVING AND INSTALLING

For all Exhaust System, Emission control component locations. Refer to Secondary Air Injection System Assembly Overview .

For all Exhaust System, Emission control removal/installation procedures and torque specifications. Refer to Secondary Air Injection System Assembly Overview

Note. All manufacturers special tools as well as common tools may contain a manufacturer specific part number. These tools may be substituted with an equivalent aftermarket tool or are available for purchase through Audi. Manufacturers special tools as well as common tools that contain a manufacturer specific part number may be referenced in the test procedure illustrations showing the tool use or installation. If the manufacturer specific tool is not being used, an equivalent aftermarket tool may be installed in the same manner as the manufacturers special tool.

THREE WAY CATALYTIC CONVERTER, CHECKING

Test requirements

  1. Battery voltage at least 12.5 volts.
  2. Oxygen Sensors OK.
  3. No leaks or damage to exhaust system.

Function test

Perform the function test in Diagnostic Mode 06. Refer to DIAGNOSTIC MODE 06 - READ TEST RESULTS FOR SPECIFIC DIAGNOSTIC FUNCTIONS .

End diagnosis and switch the ignition off.

If the specified values are exceeded

Check the exhaust system for leaks.

If necessary, repair the leak in the exhaust system.

Erase the DTC memory. Refer to DIAGNOSTIC MODE 04 - ERASE DTC MEMORY .

Perform a road test to verify Repair.

If the DTC does not return

Repair complete, Generate readiness code. Refer to READINESS CODE .

End diagnosis.

If no leaks are found in the exhaust system

Replace the catalytic converter including front exhaust pipe. Refer to Engine Mechanical, Repair. Group. 26.

Final procedures

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

  1. Check the DTC memory. Refer to «DIAGNOSTIC MODE 03 - READ DTC MEMORY»(/audi/tt/8j-2006-2010/remont/cooling-fan/#32l-generic-scan-tool-engine-codes-cbra-coupe__diagnostic-mode-03-read-dtc) .
  2. If necessary, erase the DTC memory. Refer to «DIAGNOSTIC MODE 04 - ERASE DTC MEMORY»(/audi/tt/8j-2006-2010/remont/cooling-fan/#32l-generic-scan-tool-engine-codes-cbra-coupe__diagnostic-mode-04-erase-dtc) .
  3. If the DTC memory was erased, generate readiness code. Refer to «READINESS CODE»(/audi/tt/8j-2006-2010/remont/cooling-fan/#32l-generic-scan-tool-engine-codes-cbra-coupe) .

End of diagnosis.

SECONDARY AIR INJECTION SYSTEM

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 startup time of the catalytic converter considerably, as well as significantly improves emissions quality during the cold-running phase.

Function

  1. During cold start (with coolant temperatures +15 to +35° C), the Secondary Air Injection (AIR) system blows air behind the exhaust valve for approx. 65 seconds. This produces an oxygen rich exhaust gas, causes the after burning and reduces the heating-up phase of the catalytic converter.
  2. In addition, the Secondary Air Injection (AIR) system is switched on with a delay of approx. 20 seconds during idle for 5 seconds after every subsequent engine start up to max. 80° C coolant temperature and is checked by On Board Diagnostic (OBD).

COMBINATION VALVE FOR SECONDARY AIR INJECTION, CHECKING FUNCTION AND FOR LEAKS

The following procedure is used to test all combination valves.

Special tools and workshop equipment required

  1. Hand vacuum pump

Test conditions

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

Test sequence

Remove the vacuum hose from the combination valve.

Connect the hand vacuum pump to combination valve vacuum connection.

Scheme 49

Scheme 49
Scheme 49

Disconnect the Secondary Air Injection hose -arrow-.

Scheme 50

Scheme 50
Scheme 50

Inject a light air pressure into the in Secondary Air Injection hose to close the combination valve. (do not use compressed air).

  1. The combination valve should close and seal. Air should not be able to pass through the combination valve.

Operate the hand vacuum pump.

  1. The combination valve should open. Air should be able to pass through the combination valve.

If combination valve does not open

Replace the faulty combination valve. Refer to Secondary Air Injection System Assembly Overview

End of procedure.

SECONDARY AIR INJECTION PUMP RELAY, CHECKING

Special tools and workshop equipment required

  1. Multimeter.
  2. Wiring diagram.

Test requirements

  1. Fuse -SA1- OK.
  2. Fuse -SA5- OK.
  3. Fuse -Sb6- OK.
  4. Motronic Engine Control Module (ECM) Power Supply Relay -J271- OK.
  5. Battery voltage at least 12.5 V.
  6. All electrical consumers switched off (radiator fan must NOT run during test).
  7. A/C switched off.
  8. The ignition switched off.

Test procedure

Perform a preliminary check to verify the customers complaint. Refer to GENERAL DIAGNOSIS => .

Start diagnosis

Remove the Secondary Air Injection (AIR) Pump Relay -J299-.

Checking voltage

Using a Multimeter, check the Secondary Air Injection (AIR) Pump Relay -J299- socket 1/30 to Ground (GND).

Specified value: battery voltage.

If the specified value was not obtained

Check the Secondary Air Injection (AIR) Pump Relay -J299- socket 1/30 to Battery -A- (+) for an open circuit or a short circuit.

Check the electrical harness connector for damage, corrosion, loose or broken terminals.

If necessary, repair the faulty wiring connection.

If the specified value was obtained

Switch the ignition on.

Using a Multimeter, check the Secondary Air Injection (AIR) Pump Relay -J299- socket 3/86 to Ground (GND) for voltage.

Specified value: battery voltage.

Switch the ignition off.

If the specified value was not obtained

Check the Secondary Air Injection (AIR) Pump Relay -J299- socket 3/86 to the Motronic Engine Control Module (ECM) Power Supply Relay -J271- socket 2/87 for an open circuit or a short circuit.

Check the electrical harness connector for damage, corrosion, loose or broken terminals.

If necessary, repair the faulty wiring connection.

If the specified value was obtained

Checking wiring

If the manufacturers test box is being used. Perform the following step.

Install the test box. Refer to Engine Control Module

If the manufacturers test box is not being used. Perform the following step.

Remove the Engine Control Module (ECM) -J623-. Refer to ENGINE CONTROL MODULE, REPLACING .

Using a Multimeter, check the Secondary Air Injection (AIR) Pump Relay -J299- socket 3/86 to the Engine Control Module (ECM) -J623- electrical harness connector T81 terminal 46 for resistance.

Secondary Air Injection (AIR) Pump Relay -J299- socket terminalEngine Control Module (ECM) -J623- electrical connector T81 terminal or test box socket
4/8646

Specified value: 1.5 ohms Max.

If the specification was not obtained

Check the wiring for a short circuit to each other, Battery (+), and Ground (GND).

Check the electrical harness connector for damage, corrosion, loose or broken terminals.

If necessary, repair the faulty wiring connection.

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

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

Erase the DTC memory. Refer to DIAGNOSTIC MODE 04 - ERASE DTC MEMORY

Perform a road test to verify repair.

If the DTC does not return

Repair complete, Generate readiness code. Refer to READINESS CODE => Readiness Code Description .

End diagnosis.

If the DTC does return and no malfunction is detected in the wiring and the voltage supply was OK

Replace the Engine Control Module (ECM) -J623-. Refer to ENGINE CONTROL MODULE, REPLACING .

Assembly is performed in the reverse of the removal.

Final procedures

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

  1. Check the DTC memory. Refer to «DIAGNOSTIC MODE 03 - READ DTC MEMORY»(/audi/tt/8j-2006-2010/remont/cooling-fan/#32l-generic-scan-tool-engine-codes-cbra-coupe__diagnostic-mode-03-read-dtc) .
  2. If necessary, erase the DTC memory. Refer to «DIAGNOSTIC MODE 04 - ERASE DTC MEMORY»(/audi/tt/8j-2006-2010/remont/cooling-fan/#32l-generic-scan-tool-engine-codes-cbra-coupe__diagnostic-mode-04-erase-dtc) .
  3. If the DTC memory was erased, generate readiness code. Refer to «READINESS CODE»(/audi/tt/8j-2006-2010/remont/cooling-fan/#32l-generic-scan-tool-engine-codes-cbra-coupe) .

End of diagnosis.

SECONDARY AIR INJECTION PUMP MOTOR, CHECKING

Special tools and workshop equipment required

  1. Multimeter.
  2. Wiring diagram.

Test requirements

  1. Secondary Air Injection (AIR) Pump Relay -J299- OK.
  2. Motronic Engine Control Module (ECM) Power Supply Relay -J271- OK.
  3. Battery voltage at least 12.5 V.
  4. All electrical consumers switched off (radiator fan must NOT run during test).
  5. A/C switched off.
  6. The ignition switched off.

Test procedure

Perform a preliminary check to verify the customers complaint. Refer to GENERAL DIAGNOSIS => .

Start diagnosis

Disconnect the secondary air injection hose -arrow-.

Remove the center noise insulation fasteners -1, 2, 3, 4- and the center noise insulation panel.

Scheme 51

Scheme 51
Scheme 51

Disconnect the Secondary Air Injection (AIR) Pump Motor -V101- electrical harness connector -3-.

Scheme 52

Scheme 52
Scheme 52

Checking voltage

Start engine momentarily.

Using a Multimeter, check the Secondary Air Injection (AIR) Pump Motor -V101- electrical harness connector terminals 1 to 2 for voltage.

Scheme 53

Scheme 53
Scheme 53

Switch the ignition off.

Specified value: battery voltage.

If the specified value was not obtained

Using a Multimeter, check the Secondary Air Injection (AIR) Pump Motor -V101- electrical harness connector terminal 2 to Ground (GND).

Specified value: battery voltage.

If the specified value was not obtained

Check the wiring connection from the Secondary Air Injection (AIR) Pump Relay -J299- socket 2/87 to the Secondary Air Injection (AIR) Pump Motor -V101- electrical harness connector terminal 2 for an open circuit or a short circuit.

Check the electrical harness connector for damage, corrosion, loose or broken terminals.

If necessary, repair the faulty wiring connection.

If the specified value was obtained

Checking Ground (GND)

Using a Multimeter, check the Secondary Air Injection (AIR) Pump Motor -V101- electrical harness connector terminal 1 to Ground (GND) connection 2 (on left front long member) for resistance.

Specified value: 1.5 ohms Max.

If the specification was not obtained

Check the Secondary Air Injection (AIR) Pump Motor -V101- electrical harness connector terminal 1 to Ground (GND) connection 2 (on left front long member) for a short circuit to each other, Battery (+), and Ground (GND).

Check the electrical harness connector for damage, corrosion, loose or broken terminals.

If necessary, repair the faulty wiring connection.

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

Replace Secondary Air Injection (AIR) Pump Motor -V101-. Refer to Secondary Air Injection Pump

Erase the DTC memory. Refer to DIAGNOSTIC MODE 04 - ERASE DTC MEMORY .

Perform a road test to verify repair.

If the DTC does not return

Repair complete, Generate readiness code. Refer to READINESS CODE => Readiness Code Description .

End diagnosis.

If the DTC does return and no malfunction is detected in the wiring and the voltage supply was not OK

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

Assembly is performed in the reverse of the removal.

Final procedures

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

  1. Check the DTC memory. Refer to «DIAGNOSTIC MODE 03 - READ DTC MEMORY»(/audi/tt/8j-2006-2010/remont/cooling-fan/#32l-generic-scan-tool-engine-codes-cbra-coupe__diagnostic-mode-03-read-dtc) .
  2. If necessary, erase the DTC memory. Refer to «DIAGNOSTIC MODE 04 - ERASE DTC MEMORY»(/audi/tt/8j-2006-2010/remont/cooling-fan/#32l-generic-scan-tool-engine-codes-cbra-coupe__diagnostic-mode-04-erase-dtc) .
  3. If the DTC memory was erased, generate readiness code. Refer to «READINESS CODE»(/audi/tt/8j-2006-2010/remont/cooling-fan/#32l-generic-scan-tool-engine-codes-cbra-coupe) .

End of diagnosis.

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