With Manufacturer's Scan Tool

Operational Readiness Of Oxygen Sensor After Three Way Catalytic Converter (TWC), Checking

Function
To test the operational readiness of the oxygen sensor after Three Way Catalytic Converter (TWC), the fuel/air mixture is enriched while the oxygen sensor voltage is observed. The oxygen sensor voltage must rise.

Special tools, test equipment and auxiliary items
- VAG 1551 scan tool (or VAG 1552 mobile scan tool) with VAG 1551/3B cable

Test conditions
- Engine Coolant Temperature (ECT) must be at least 80°C.

Functional check
- Connect VAG 1551 scan tool ((VAG 1552). Start engine and select "Address word" 01 of Motronic Engine Control Module (ECM) -J220-. Engine must be running at idle speed.

Indicated on display:

Rapid data transfer HELP
Select function XX

- Press buttons -0- and -4- for function "Introduction of basic setting" and confirm entry with -Q- button.

Indicated on display:

Basic setting
Input display group number XXX

- Press buttons -0-, -3- and -6- for "Display group number 36" and confirm entry with -Q- button.

Indicated on display: (1...2 Display zones)

System in basic setting 36 ->
1 2

- Allow engine to run at idle until readout in display zone 2 jumps from "Test OFF" to "Test ON".
- Observe oxygen sensor voltage in display zone 1. Value must rise.
- Allow engine to continue to run at idle until specified value "B1-S2 OK" appears in display zone.

If the specifications are obtained:
- Press -> button.
- Press buttons -0- and -6- for function "End output" and confirm entry with -Q- button.
- Switch off ignition.

If the specifications are not obtained:
- Road test vehicle to free oxygen sensor of possible contaminates and repeat test.
Observe the valid safety precautions when road testing.

If the specifications are again not obtained:
- Check basic voltage.