Function Check

Oxygen Sensor Function, Oxygen Sensor After Catalyst, Checking

Function
To test the operational readiness of the sensor behind catalytic converter, the mixture is enriched and the oxygen sensor voltage is observed. Oxygen sensor voltage must increase.

Special tools and equipment
- V.A.G 1551 scan tool or 1552 scan tool with cable VAG 1551/3

Test conditions
- Coolant temperature must be at least 80 °C, See display group 04, display zone 3.

Functional check
- Connect V.A.G 1551 scan tool ((VAG 1552). Start engine and select "Address word" 01 of engine control module. Engine must be running at idling speed. [1][2]Reading and Clearing Diagnostic Trouble Codes

Indicated on display:

Rapid data transfer HELP
Select function XX

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

Indicated on display:

Basic setting
Input display group number XXX

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

Indicated on display: (1 to 2 = Display zones)

Read measuring value block 36 ->
1 2

- Leave engine at idle until the indication in display field 2 jumps from "Test OFF" to "Test ON".
- Observe the oxygen sensor voltage in display field 1. The value must increase.
- Continue to let engine run at idle until display field 2 indicates the specified value "B1-S2 OK".

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

If the specifications are not attained:
- Road test vehicle to free Oxygen sensor of possible residues and repeat test.
Observe the valid safety precautions when carrying out a road test.

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