Aging Check

Oxygen sensor aging, oxygen sensor before catalytic converter, checking

Special tools and equipment







- V.A.G 1551 scan tool (or VAG 1552 mobile scan tool) with VAG 1551/3B cable
- VAG 1788/10 RPM adjuster

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 -4- to select "Display group number 34". Press -Q- button to confirm input.

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


System in basic setting 34 ->
1 2 3 4


- Use VAG 1788/10 RPM adjuster to adjust engine RPM to: 2300 to 2500 RPM:
- Maintain engine speed until indication in display field 4 jumps from "Test OFF" to "Test ON". The catalytic converter temperature in display field 2 must be at least 350 °C.
- Check dynamic factor in display field 3: Specification: maximum 2.5
- Continue to maintain engine speed until display field 4 indicates specified value "B1-S1 OK".

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:
- Replace Heated Oxygen Sensor (HO2S) -G39-.