Operation 11: Catalytic converter diagnosis

2009 Audi A6 BaseSECTION Operation 11: Catalytic converter diagnosis
WARNING: This page is about a different car, the 2006 Audi A4, 2005 Audi A4, 2004 Audi A4, 2003 Audi A4, and 2002 Audi A4. However, it is still accessible from the selected car via links, so may be relevant.

Test conditions 

  • Engine running at idling speed
Fig 1: Diagnostic System VAS 5051: Display
GW00006285Courtesy of VOLKSWAGEN UNITED STATES, INC.

Display on VAS5051:

1 - Enter display group

  • Enter "198" for "display group number 198" in zone -2- and confirm entry by pressing -Q- button.
Fig 2: Diagnostic System VAS 5051: Display - Display Fields
GW00015572Courtesy of VOLKSWAGEN UNITED STATES, INC.

Display on VAS5051:

  • Activate basic setting by pressing -A- button.
  • Press accelerator and brake pedal simultaneously. Engine speed increases to approx. 2200 RPM.

Test conditions 

  • Accelerator and brake pedal pressed simultaneously, engine runs at approx. 2200 RPM.
  • Check indication in display fields -2- and -4-.
  Display zones 
  1 2 3 4
Display group 198: Diagnosis of catalytic converter (Bank 1 and Bank 2) 
Display  x.xx ---  x.xx --- 
Display  Measured value catalytic converter - conversion, Bank 1 Diagnosis status  Measured value catalytic converter - conversion, Bank 2 Diagnosis status 
Range    Test OFF 
Test ON 
Cat. B1 OK 
Cat. B1 NOK 
  Test OFF 
Test ON 
Cat. B2 OK 
Cat. B2 NOK 
Specif.value  0...0.35 Cat. B1 OK  0...0.35 Cat. B2 OK 
Note:    If "Cat. B1 NOK" is displayed: Check DTC memory. Refer to Diagnostic Trouble Code (DTC) memory, checking  . If no DTC is stored, replace catalytic converter.   If "Cat. B1 NOK" is displayed: Check DTC memory. Refer to Diagnostic Trouble Code (DTC) memory, checking  . If no DTC is stored, replace catalytic converter.

If specified value "Cat. B1 OK" is obtained:

  • Press ← button.
  • Depress accelerator pedal completely (swiftly) and then release it (brief acceleration to at least 4000 RPM).
WARNING:

Test procedure cannot continue successfully without this brief acceleration!

  • Perform next operation.
RENDER: 1.0x

NO RELATED

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • You smell fuel, burning insulation, or see smoke.
  • Brakes feel soft, pull hard to one side, or make grinding noises.
  • The engine overheats, stalls repeatedly, or misfires under load.
  • You are missing required tools, torque specs, or safe lifting equipment.
  • You are not confident in the next step or safety outcome.