Oxygen Sensor Aging After TWC, Check

Oxygen Sensor After Catalyst Aging, Checking

Special tools and equipment







- Scan tool VAG 1551 or vehicle system tester V.A.G 1552 with cable VAG 1551/3B
- V.A.G 1788/10 Engine speed adjuster

Test conditions
Coolant temperature must be at least 85 °C See display group 04, display zone 3

Functional check
- Connect scan tool VAG 1551 (V.A.G 1552). Start engine and select "Address word" 01 of engine control module. Engine must be running at idle speed.

Connecting scan tool and selecting Engine Control Module (ECM). Refer to "Scan Tool Testing/Scan Tool Connecting and Initial Checks/VAG1551 Scan Tool" Testing and Inspection

Indicated on display


Rapid data transfer HELP
Select function XX


- Press buttons 0 and 4 for function "Basic Setting" and confirm entry with Q button.

Indicated on display


Basic setting
Input display group number XXX


- Press buttons 0, 4 and 3 for "Display group number 34" and confirm entry with Q button.

Indicated on display (1-4 = Display zones)


System in basic setting 43 ->
1 2 3 4


- Set engine speed to at 2300 RPM using the speed regulator V.A.G 1788/10:
- Maintain engine speed at 2300 RPM until display in display zone 4 jumps from "Test OFF" to "Test ON". Catalyst temperature in display zone 2 must be at least 365 °C
- Continue to maintain speed at 2300 RPM until specification "B1-S1 OK" appears in display zone 4.

If the specification is not obtained:
- Press -> button.
- Press buttons 0 and 6 for function "End output" and confirm entry with Q button.
- Switch ignition off.

If the specifications are not attained:
- Carry out a road test to free oxygen sensor of possible residues and repeat the test.

Observe the valid safety precautions when carrying out a road test.

If the specifications are again not attained:
- Replace oxygen sensor before catalyst (G39)
- Check DTC memory, if necessary, repair any malfunctions and then erase DTC memory. Refer to "Displaying and Reading Trouble Codes/With Manufacturers Scan Tool/DTC Memory Checking and Erasing" Testing and Inspection
- Read readiness code. If DTC memory has been erased or engine control module was disconnected from permanent positive, readiness code must be generated again.
Refer to "Monitors, Trips and/or Drive Cycle/Readiness Code, Displaying" Testing and Inspection
Refer to "Monitors, Trips and/or Drive Cycle/Readiness Code, Generating" Testing and Inspection