Oxygen Sensor (O2S) Behind TWC Checking

Oxygen Sensor (O2S) Behind Three Way Catalytic Converter (TWC), Checking

Requirements
- HO2S properly installed
- Exhaust system free of leaks

Checking
- Connect VAG1551 orVAG1552 Scan Tool (ST), and press buttons -0- and -1- to insert "Engine Electronics" address word 01 (engine running at idle). Refer "Scan Tool Testing/Scan Tool Connecting and Initial Checks/Connecting VAG1551 or VAG1552 Scan Tool" Testing and Inspection

Indicated on display


Rapid data transfer HELP
Select function XX


- Press buttons -0- and -8- to select "Read Measuring Value Block" function 08, and press -Q- button to confirm input.

Indicated on display


Read Measuring Value Block
Input display group number XXX


- Press buttons -0-, -0- and -3- to input display group number 3 (003), and press -Q- button to confirm input.

Indicated on display


Read Measuring Value Block 3 ->
1 2 3 4


- Check specified values for basic functions at engine idle speed (display field 3):







Continue checking only after engine coolant temperature in display field 3 has reached at least 85 °C (185 °F).
- Press -C- button.

Indicated on display


Read Measuring Value Block
Input display group number XXX


- Press buttons -0-, -2- and -7- to input display group number 27 (027), and press -Q- button to confirm input.

Indicated on display


Read Measuring Value Block 27 ->
1 2 3 4


- Check specified values for Oxygen Sensors (O2S and O2S 2) behind Three Way Catalytic Converters (TWC) See display fields 1-4:







- Press -> button to advance program sequence.
- Press buttons -0- and -6- to select "End Output" function 06, and press -Q- button to confirm input.