With Manufacturer's Scan Tool

Oxygen Sensor And Oxygen Sensor Control After Three Way Catalytic Converter (TWC), Checking

NOTE:
- Raise vehicle to reach oxygen sensor connector.
- Only gold terminals may be used for servicing terminals 3 and 4 in connector for oxygen sensor.

Special tools, test equipment and auxiliary items
- VAG 1551 scan tool or VAG 1552 mobile scan tool with VAG 1551/3B cable
- VAG 1598/31 test box
- VAG 1526 hand multimeter or VAG 1715 multimeter
- VAG 1594 adapter set
- Electrical Wiring Diagram

Test conditions







- All fuses must be OK
- Battery voltage must be at least 11.5 V.
- Exhaust system between Three Way Catalytic Converter (TWC) and cylinder head must be free of leaks
- Engine Coolant Temperature (ECT) must be at least 80 °C, see display group 04, display zone 3

Functional check
- Connect VAG 1551 scan tool ((VAG 1552). Start engine and select "Address word" 01 of ECM. Engine must be running at idle speed. Connecting scan tool and selecting Engine Control Module. [1][2][3]Connecting VAG 1551 Scan Tool

Indicated on display


Rapid data transfer HELP
Select function XX


- Press buttons -0- and -8- for function "Read measured value block" and confirm entry with -Q- button.

Indicated on display


Read measuring value block
Input display group number XXX


- Press buttons -0-, -3- and -0- for "Display group number 30" and confirm entry with -Q- button.

Indicated on display (1 to 2 = Display zones)


Read measuring value block 30 ->
1 2


- Check status of oxygen sensor control after Three Way Catalytic Converter (TWC) (display zone 2).

Specification: 1 1 0







Significance of 3 digit number block in display zone 2







If the specification is obtained:
- Change to display group 36 as follows:
- Press -> button.
- Press buttons -0- and -4- for "Basic Setting" function and confirm entry with -Q- button.

Indicated on display


Basic setting
Input display group number XXX


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

Indicated on display (1 to 2 = Display zones)


System in basic setting 36 ->
1 2


- Check oxygen sensor voltage after Three Way Catalytic Converter (TWC) in display zone 1.

Specification: 0.100...0.900 V (can fluctuate slightly)

- Maintain engine speed at 1800-2200 RPM.
If the diagnostic is initiated from Engine Control Module the display in display zone 4 jumps from "Test OFF" to "Test ON."

Specification: "B1-S2 OK." appears in display zone 2.


NOTE: It can take a few minutes until display jumps from "Test ON" to "B1-S2 OK".







If the specification is obtained:
- Press -> button.
- Press buttons -0- and -6- for function "End output" and confirm entry with -Q- button.
- Switch off ignition.

Continuation

If the specification is not obtained:
- Press -> button.
- Press buttons -0- and -6- for function "End output" and confirm entry with -Q- button.
- Check DTC Memory, if necessary, repair any malfunctions and then Erase DTC Memory, Checking and Erasing DTC Memory. Reading Diagnostic Trouble Codes
- Perform a road test to remove possible contaminates on oxygen sensor and repeat check.
Observe the valid safety precautions when carrying out a road test

If the specifications are again not obtained:
- Replace Oxygen Sensor (O2S) after Three Way Catalytic Converter (TWC) -G130-, item 8.
- Check DTC Memory, if necessary, repair any malfunctions and then Erase DTC Memory, Checking and Erasing DTC Memory. Reading Diagnostic Trouble Codes
- Read readiness code. If DTC memory has been erased or Motronic Engine Control Module (ECM) -J220- was disconnected from battery positive, readiness code must be generated again.
Monitors, Trips, Drive Cycles and Readiness Codes
Monitors, Trips, Drive Cycles and Readiness Codes

Evaluating display group 36, display zone 1 - oxygen sensor voltage oxygen sensor after Three Way Catalytic Converter (TWC)







Possible causes of malfunction if sensor control frequency is too slow:
- Slots or holes in sensor body are blocked
- Sensor vent hole in area of connecting wire is blocked
- Sensor has been overheated (glazed)
- Sensor has been damaged by leaded fuel

Checking basic voltage for oxygen sensor 2







- Remove protective cover -arrows- and separate 4-pin connector (black/brown) -1- to Oxygen Sensor (O2S) after Three Way Catalytic Converter (TWC) -G130-.







- Connect multimeter with auxiliary cables from VAG 1594 to measure voltage at terminals 3 + 4 (connector to Motronic control module).
- Start engine and measure basic voltage.

Specification: 0.400 to 0.500 V

- Switch off ignition.

If the specification is not obtained:
- Check oxygen sensor wiring.

If the specification is obtained:
- Replace Oxygen Sensor after Three Way Catalytic Converter (TWC) -G130-, item 8.
- Check DTC Memory, if necessary, repair any malfunctions and then Erase DTC Memory, Checking and Erasing DTC Memory. Reading Diagnostic Trouble Codes
- Read readiness code. If DTC memory has been erased or Motronic Engine Control Module (ECM) -J220- was disconnected from battery positive, readiness code must be generated again.
Monitors, Trips, Drive Cycles and Readiness Codes
Monitors, Trips, Drive Cycles and Readiness Codes

Checking Oxygen Sensor wiring, oxygen sensor 2
- Remove inner plenum chamber cover, left.







- Connect VAG 1598/31 test box to control module wiring harness. Motronic Engine Control Module (ECM) -J220- is not connected by this action.







- Check wiring for open circuit between test box and 4-pin connector to Motronic control module using Electrical Wiring Diagram.
- terminal 3 + socket 68
- terminal 4 + socket 69

Wire resistance: Max. 1.5 Ohms

- Check wiring at connector terminals 3 + 4 for short circuit to terminals 1 + 2 using Electrical Wiring Diagram.
- terminal 4 and socket 68

Specification: Infinity Ohms

If no wiring malfunction is found:
- Replace Motronic Engine Control Module (ECM) -J220-.