Volkswagen Workshop Service and Repair Manuals

Only engine codes AKP, AUC, AUD

Special tools, workshop equipment, testers, measuring instruments and auxiliary items required

• ◆ Fault reader V.A.G 1551 or vehicle system tester V.A.G 1552 with cable V.A.G 1551/3A

Test conditions

• ● → Fuse No. 1 must be OK.
• ● Vehicle stationary
• ● All electrical consumers, e.g. lights and rear window heating must be switched off.
• ● If the vehicle is equipped with an air conditioning system, this must be switched off.
• ● Exhaust system between catalyst and cylinder head must be free of leaks
• ● Coolant temperature must be at least 80 °C, =>display group 04, display zone 3.
• ● Intake air temperature less than 60°C
  =>display group 04, display zone 4

Functional check

• ‒ Connect fault reader V.A.G 1551 (V.A.G 1552). Start engine and select the engine control unit with the "Address word" 01. Connecting fault reader and selecting engine control unit:

=> Repair group 01; General to self-diagnosis; Connecting fault reader V.A.G 1551 and selecting engine control unit

Lambda probe dynamics diagnosis

• ‒ Press keys 0 and 4 for the "Introduce basic setting" function and confirm entry with Q key.

• ‒ Press keys 0, 3 and 4 for "Display group number 34" and confirm entry with Q key.

• ‒ Depress brake pedal.

• The engine speed is increased to
       approx. 1100...1300 rpm
  by the engine control unit

• ‒ Allow engine to run at increased engine speed until
       display zone 4 jumps from "Test OFF" to "Test ON". The catalyst temperature in
       display zone 2 must be a minimum of 400 °C.

Note:

This process can take a few minutes.

• ‒ Check the amplitude quality in display zone 3:
       Specification: 0.7... 2.00
• ‒ Allow engine to continue to run at increased engine speed until
       display zone 4 displays the specification "B1-P1 OK.".

If the display does not indicate as described:

• ‒ Interrogate fault memory:

=> Repair group 01; Fault memory; Interrogating and erasing fault memory of engine control unit

If the display indicates as described:

• ‒ Press C key.

• The engine speed drops to idling speed.

Catalyst diagnosis

Note:

The diagnosis will only be terminated if the Lambda probe dynamics diagnosis is first successfully completed.

• ‒ Press keys 0, 4 and 6 for "Display group number 46" and confirm entry with Q key.

• ‒ Depress brake pedal.

• The engine speed is increased to
       approx. 1100...1300 rpm
  by the engine control unit

• ‒ Allow engine to run at increased engine speed until
       display zone 4 jumps from "Test OFF" to "Test ON". The catalyst temperature in
       display zone 2 must be a minimum of 400 °C.

• ‒ Check the amplitude ratio in display zone 3:
       Specification: max. 0.50
• ‒ Allow the engine to continue to run at increased engine speed until
       display zone 4 displays "Cat B1 OK."

If the display does not indicate as described:

• ‒ Interrogate fault memory:

=> Repair group 01; Fault memory; Interrogating and erasing fault memory of engine control unit

If the display indicates as described:

• ‒ Press ⇒key.

• The engine speed drops to idling speed.

• ‒ Press keys 0 and 6 for the function "End output" and confirm entry with the Q key.
• ‒ Switch off ignition.