With Manufacturer's Scan Tool

Catalyst, checking

Special tools and equipment





- V.A.G 1551 Fault reader

Note: The VAG1552 vehicle system tester can be used instead of the VAG1551 Scan Tool, but a print-out is not possible.

- VAG 1551/3B Cable
- VAG1788/10 speed regulator

Test sequence
- Connect fault reader V.A.G 1551 (V.A.G 1552). Start engine and select engine control unit with "Address word" 01. Connecting fault reader and selecting engine control unit.

Note: The diagnosis will only be terminated if the oxygen sensor aging diagnosis is first successfully completed.

Indicated on display:

Rapid data transfer HELP
Select function XX

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

Indicated on display:

Basic setting
Input display group number XXX

- Press keys 0, 3 and 4 for display group number 34 and confirm entry with Q key.

Indicated on display: (1 - 4 = Display zones=)

System in basic setting 34 ->
1 2 3 4

- Set engine speed to 1800 to 2200 RPM using speed regulator V A G 1788/10:
- Maintain engine speed at 1800 to 2200 RPM until catalytic converter temperature in display zone 2 is between 350 and 500°C

If the diagnosis is initiated from the engine control module the display in display zone 4 jumps from "Test OFF" to "Test ON"

- Check cycle duration in display zone 3:
Specification: maximum 199

- Continue to maintain speed at 1800 to 2200 RPM until specification "B1-S1 OK" appears in display zone 4






If the display does not indicate as described:

- Remove engine speed adjuster VAG1788/1 0 from accelerator pedal.
- Press -> key.
- Check DTC memory:
- Read out readiness code:

If DTC memory has been erased or the engine control module separated from the permanent positive, the readiness code must be generated again.

If the display indicates as described:
- Press C key.

Indicated on display:

Basic setting
Input display group number XXX

- Press keys 0, 4 and 6 for "display group number 46" and confirm entry with Q key.

Indicated on display: (1 - 4 = Display zones)

System in basic setting 46 ->
1 2 3 4

- Maintain engine speed at 1800 to 2200 RPM until catalyst temperature in display zone 2 increases to above 440°C

If the diagnostic is initiated from engine control module the display in display zone 4 jumps from "Test OFF" to "Test ON"

- Check catalyst conversion (amplitude condition) in display zone 3:
Specification: max. 0.20

- Continue to maintain speed at 1800 to 2200 RPM until the specification "Cat B1 OK " appears in display zone 4

Note: This process can take a few minutes. If no result is displayed within 15 seconds, change RPMs within specified range.






If the display does not indicate as described:
- Remove engine speed adjuster VAG1788/1 0 from accelerator pedal.
- Press -> key.
- Check DTC memory
- Read readiness code

If the DTC memory has been erased or the engine control module separated from permanent positive, the readiness code must be generated again.

If the display indicates as described:
- Remove engine speed adjuster VAG1788/1 0 from accelerator pedal.
- Press -> key.

Indicated on display:

Rapid data transfer HELP
Select function XX

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