With Manufacturer Scan Tool
Oxygen Sensor and Oxygen Sensor Control Before Three Way Catalyst, Checking
Special tools, workshop equipment, testers, measuring instruments and auxiliary items required
- VAG 1551/1552 Scan Tool using VAG 1551/3 Adaptor cable
- VAG 1598/22 Test Box
- Fluke 83 multimeter
- VW 1594 Adaptor kit
- Wiring diagram
Requirements
- Engine Coolant Temperature must be 85 °C minimum See Display group 04, Display field 3
Functional check
- Connect VAG 1551/1552 Scan Tool. Refer to "Scan Tool Testing/Scan Tool Connecting and Initial Checks" Testing and Inspection
- Start engine and let idle
- Press 0 and 1 buttons to select "Engine Electronics" address word 01.
Indicated on display (example only)
06A906018AB Motronic M5.9.2 HS V06 ->
Coding 00000 WSC 00000
- Press -> button.
Indicated on display
Rapid data transfer HELP
Select function XX
- Press 0 and 8 buttons to select "Read Measuring Value Block" function 08.
- Press Q button to enter input.
Indicated on display
Read measuring value block
Input Display group number XXX
- Press 0, 3 and 2 buttons to select "Display group 32"
- Press Q button to enter input.
Indicated on display (1 to 4 = Display fields)
Read measuring value block 32 ->
1 2 3 4
- Check specifications for Oxygen control before Three Way Catalyst (Display fields 1 to 3).
If specifications obtained Switch to Display group 33 as follows:
- VAG 1551: Press 3 button
- VAG 1552: Press uparrow button
Indicated on display (1 to 4 = Display fields)
Read measuring value block 33 ->
1 2 3 4
- Check Oxygen sensor heating. Oxygen Sensor, Checking
If specifications obtained
- Press -> button.
Indicated on display
Rapid data transfer HELP
Select function XX
- Press 0 and 6 buttons to select "End output" function 06.
- Press Q button to enter input.
- Switch OFF ignition.
If specification in Display field 1 is not obtained, or value does not fluctuate 2 % minimum
- Take test drive to remove possible residue build up on Oxygen sensor and repeat check.
Observe appropriate safety precautions during road test.
If specification in Display field 1 is not obtained even after a road test, or value does not fluctuate 2 % minimum
- Check Oxygen sensor heating. Oxygen Sensor, Checking
If value shown in Display field 1 remains constant
- Note Oxygen sensor Voltage in Display field 2
- Press -> button.
Indicated on display
Rapid data transfer HELP
Select function XX
- Press 0 and 6 buttons to select "End output" function 06.
- Press Q button to enter input.
- Switch OFF ignition.
Display group 32, evaluating
Display group 33, evaluating
Basic voltage checking
- Remove protective cover -arrows- and disconnect black 4-pin harness connector to Oxygen sensor G39 (before Three Way Catalyst).
- Switch Fluke 83 multimeter to Voltage range
- Connect Fluke 83 multimeter between ECM harness connector terminals 3 + 4 using jumper wires from VW 1594 adaptor kit.
- Start engine and measure the basic Voltage.
- Specification: 0.40 to 0.50 Volts
- Switch OFF ignition.
If specification not obtained
- Check Oxygen sensor wiring.
If specification obtained
- Replace Oxygen sensor G39.
- Display the Readiness code. Refer to "Monitors, Trips and/or Drive Cycle (Readiness Codes)/Displaying Readiness Code", Monitors, Trips, Drive Cycles and Readiness Codes
- If DTC memory was erased or if the ECM was disconnected from Battery + , set the Readiness code. Refer to "Monitors, Trips and/or Drive Cycle (Readiness Codes)/Setting Readiness Code", Monitors, Trips, Drive Cycles and Readiness Codes
Oxygen sensor wiring, checking
- Connect VAG 1598/22 Test Box to ECM wiring harness.
- Check wiring for open circuit between Test Box and 4-pin harness connector to ECM using Wiring diagram.
- Terminal 3 + socket 25
- Terminal 4 + socket 26
Wire resistance: 1.5 Ohms maximum
- Check wiring at 4-pin connector for shorts to one another.
Terminal 4 + socket 25 specification: Infinity Ohms
If wiring OK:
- Replace Engine Control Module.