With Manufacturer's Scan Tool
Oxygen Sensor Heater For Heated Oxygen Sensors (HO2S) After Catalytic Converter, Checking
When servicing terminals in harness connector of Heated Oxygen Sensor (HO2S), use only gold-plated terminals.
Special tools and equipment
- V.A.G 1551 Scan Tool (or VAG 1552 mobile scan tool) with VAG 1551/3 cable
- VAG 1598/31 test box
- VAG 1526 multimeter or VAG 1715 multimeter
- VAG 1594 connector test kit
- Wiring diagram
Test requirements
- Fuse no.34 must be OK.
- Battery voltage must be at least 11.5 volts.
- Fuel Pump (FP) relay must be working properly.
Test sequence
- Connect V.A.G 1551 scan tool (VAG 1552). Start engine and select the Engine Control Module (ECM) using address word 01. Refer to Scan Tool Testing/Scan Tool Connecting and Initial Checks/Connecting V.A.G 1551 Scan Tool [1][2][3]Connecting VAG 1551 Scan Tool
Indicated on display
Rapid data transfer HELP
Select function XX
- Press buttons -0- and -8- to select "Read measuring value block" function 08. Press -Q- button to confirm input.
Indicated on display
Read Measuring Value Block
Input display group number XXX
- Press 0, 3 and 0 for function "display group number 30", and then press Q to exit from input mode.
Indicated on display (1 - 4 = display fields)
Read Measuring Value Block 30 ->
1 2 3 4
- Check the status of oxygen sensor heater in display fields 2 and 4:
Specification: 111
011 also briefly, since the oxygen sensor heater is clocked. Evaluating measuring value blocks. Refer to Scan Tool Testing/Measuring Value Blocks/Evaluating Display Groups 30-44, 99 Display Groups 30-44, 99 (Oxygen Sensor Control)
If specified value is not obtained:
- Press -> button.
- Press buttons -0- and -6- to select "End Output" function 06. Press -Q- button to confirm input.
- Switch ignition off.
- Unplug 4-pin harness connector going to corresponding Heated Oxygen Sensor (HO2S):
Oxygen Sensor (O2S) Behind Three Way Catalytic Converter (TWC) -G130-, bank 1 4-pin harness connector (green) (arrow).
Oxygen Sensor (O2S) 2 Behind Three Way Catalytic Converter -G131-, bank 2 4-pin harness connector (brown) (arrow).
- Check oxygen sensor heater on connector to Heated Oxygen Sensor (HO2S) terminals 1 + 2 for continuity
Specification: max. 200 Ohms
If specified value is not obtained:
- Replace appropriate Heated Oxygen Sensor (HO2S).
If expected value is not obtained:
- Check Ground (GND) connection of appropriate oxygen sensor heater.
- Switch ignition off.
- Connect VAG 1598/31 test box to control module wiring harness. Engine Control Module (ECM) is not connected.
- Check wire connection of terminal 2 of appropriate connector of Heated Oxygen Sensor (HO2S) for continuity to test box.
Specification: max. 1.5 Ohms
Connector to Oxygen Sensor (O2S) VAG 1598/31 test box socket
Behind Three Way Catalytic Converter
(TWC) -G130-, bank 1 terminal
2 63
Connector to Oxygen Sensor (O2S) VAG 1598/31 test box socket
Behind Three Way Catalytic Converter
(TWC) -G130-, bank 2 terminal
2 6
If expected value is not obtained:
- Connect together sockets 62 + 65 of test box using auxiliary wires from VAG 1594. Transfer Fuel Pump (FP) must be running.
- Connect multimeter to terminals 1 + 2 of appropriate connector to make voltage measurement.
Specification: at least 11.5 V
If there is no voltage:
- Switch ignition off.
- Check wire connection from terminal 1 to Fuel Pump (FP) relay (J17) (see wiring diagram).
If voltage supply and wires are in order:
- Replace Engine Control Module (ECM).
- Read readiness code. If DTC memory was erased or Engine Control Module (ECM) was disconnected from continuous B+ supply, readiness code must be re-generated. Monitors, Trips, Drive Cycles and Readiness Codes