With Manufacturer's Scan Tool
Heated Oxygen Sensor (HO2S) For Oxygen Sensor Before Three Way Catalytic Converter (TWC), Checking
NOTE:
- Raise vehicle to reach oxygen sensor connector
- Only gold-plated terminals must be used to repair the terminals in the oxygen sensors connectors.
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
- The battery voltage must be at least 11.5 V
- Fuel pump relay must be OK
Test sequence
- Connect VAG 1551 scan tool ((VAG 1552). Start engine and select "Address word" 01 of Motronic Engine Control Module (ECM) -J220-. Engine must be running at idle speed. Connecting scan tool and selecting Motronic Engine Control Module (ECM) -J220-. [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 measuring value block" and confirm entry with -Q- button.
Indicated on display
Read measuring value block
Input display group number XXX
- Press buttons -0-, -4- and -1- for "Display group number 41" and confirm entry with -Q- button.
Indicated on display (1 to 4 = Display zones)
Read measuring value block 41 ->
1 2 3 4
- Run engine for 2 minutes at idling speed.
- Check status of Heated Oxygen Sensor (HO2S) before catalytic converter in display field 2: Display: Htg.bC.ON, Htg.bC.OFF (alternating)
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 specifications are not obtained:
- Press -> button.
- Press buttons -0- and -6- for function "End output" and confirm entry with -Q- button.
- Switch off ignition.
- Remove protective cover -arrows- and separate 6-pin connector (black) -1- to Heated Oxygen Sensor (HO2S) before Three Way Catalytic Converter (TWC) -G39-.
- Set multimeter to measure resistance and connect it to terminals 3 + 4 of connector to oxygen sensor. Check oxygen sensor heating for closed circuit.
Specification: 2.5...10 Ohms (at room temperature)
If it is determined that oxygen sensor heating has an open circuit:
- Replace Heated Oxygen Sensor (HO2S) -G39-.
- 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
If oxygen sensor heating has continuity:
Checking voltage supply
- Set multimeter to measure voltage and connect to terminal 3 (connector to Motronic Engine Control Module (ECM) -J220-) and Ground (GND).
- Start engine and run at idling speed.
- Measure voltage supply:
Specification: 11.0 to 14.5 V
If the specification is not obtained:
- Check wiring from terminal 3 to Fuel Pump (FP) Relay -J17- using Electrical Wiring Diagram.
If the specification is obtained:
- Connect multimeter using aux. cables from VAG 1594 to measure voltage at terminals 3 and 4 (connector to Motronic Engine Control Module (ECM) -J220-).
- Measure voltage supply and note display group 41, display zone 2.
Display: Htg.bC.ON:
- Specification: 11.0 to 14.5 V
Display: Htg. bC.ON/Htg.bC.OFF (alternating):
- Specification: Between 0.0 to 12.0 V fluctuating
- Switch off ignition.
If no voltage is present:
- 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 6-pin connector according to Electrical Wiring Diagrams.
terminal 4 + socket 5
Wire resistance: Max. 1.5 Ohms
If no wiring malfunction is found:
- Replace Motronic Engine Control Module (ECM) -J220-.