Operational Readiness

Operational readiness of oxygen sensor behind catalytic converter, checking

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

Special tools and equipment

- V.A.G 1551 scan tool (or VAG1552 mobile scan tool) with VAG 1551/3B cable

Test requirement
- Coolant temperature must be at least 80 °C, See display group 04, display field 3

Function test
- Connect V.A.G 1551 scan tool (VAG 1552). Start engine and select the Engine Control Module (ECM) using address word 01. (connecting scan tool and selecting ECM). Refer to "Scan Tool Testing/Scan Tool Connecting and Initial Checks/Connecting VAG 1551 Scan Tool", Testing and Inspection

Indicated on display:


Rapid data transfer HELP
Select function XX


- Press buttons -0- and -4- to select "Basic Setting" function 04. Press -Q- button to confirm input.

Indicated on display:


Basic setting
Enter display group number XXX


- Press buttons -0-, -3- and -6- to select "Display group number 36". Press -Q- button to confirm input.

Indicated on display: (1 to 4 = display fields)


System in basic setting 36 ->
1 2 3 4


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

If specified values are obtained:
- Press -> button.
- Press buttons -0- and -6- to select "End Output" function 06. Press -Q- button to confirm input.
- Switch ignition off.

If specified values are not obtained:
- Perform a road test to free the Heated Oxygen Sensor (HO2S) of any possible residue, and repeat the test.

Observe the safety precautions that apply to road tests.

If specified values are not obtained again:
- Check primary voltage. Sensor and Control Check