After Three Way Catalytic Converter
HEATED OXYGEN SENSOR AFTER THREE WAY CATALYTIC CONVERTER AND OXYGEN SENSOR CONTROL, CHECKING
Special Tools, Testers And Auxiliary Items
- VAG 1551/1552 scan tool with VAG 1551/3 adapter cable
- VAG 1598/18 test box
- Multimeter (Fluke 83 or equivalent)
- Connector test kit VW 1594
- Wiring diagram
Test Conditions
- Coolant temperature at least 80 °C 176 °F)
Functional Check
- Engine running at idle
- Connect VAG 1551/1552 scan tool and select "Engine Electronics" address word 01. Refer to "On-Board Diagnostics II With VAG 1551". Testing and Inspection
Indicated on display
Rapid data transfer HELP
Select function XX
- Press buttons -0- and -8- to select "Read Measuring Value Block" function 08 and press -Q- button to confirm input.
Indicated on display
Read Measuring Value Block HELP
Input display group number XXX
- Press buttons -1-, -1- and -6- to input display group 116 and press -Q- button to confirm input.
Indicated on display (1-4 = Display fields)
Read Measuring Value Block 116 ->
1 2 3 4
- Note HO2S voltage (display field 3).
- Carry out test drive to remove possible residue from HO2S and repeat the check.
If the specification in display field 3 is not attained even after a test drive:
- Check O2S heating. Oxygen Sensor Heating, Checking
- Increase engine speed to above 3000 RPM.
If the value in display field 3 remains constant See evaluating display group 116.
Evaluating Display Group 116:
Relevance Of Values In 8-digit Number Block:
Checking Basic Voltage
- Separate 4-pin connector -2- (brown) to HO2S 2 -G108- (after three way catalytic converter).
- Connect multimeter using test leads from VW 1594 to measure voltage between terminals 3 and 4 (ECM side of harness connector).
- Start engine and measure basic voltage.
Specification: 0.40-0.50 volts.
- Switch ignition off.
If the specification is not attained:
- Check HO2S wiring
If the specification is attained:
- Replace HO2S 2 -G108- (after three way catalytic converter).
Checking Heated Oxygen Sensor (HO2S) Wiring
- Connect VAG 1598/18 test box to ECM wiring harness.
- Separate 4-pin connector -2- (brown) to HO2S 2 -G108- (after three way catalytic converter).
- Check wiring between test box and 4-pin connector to ECM for open circuit according to wiring diagram.
- Terminal 3 and test box socket 58
- Terminal 4 and test box socket 13
Resistance: maximum 1.5 Ohms
- Additionally, check the wiring to 4-pin connector for short circuit to one another.
Terminal 4 and test box socket 58
Specification: Infinity Ohms
- Check shielding for short circuit to HO2S wiring.
- Terminal 4 and test box socket 56
- Terminal 3 and test box socket 56
Specification: Infinity Ohms
If no wiring malfunction is detected:
- Replace Engine Control Module (ECM) -J220-.
- Read the readiness code. If DTC memory has been erased, repair must be verified via appropriate display group See Readiness code, creating. Refer to "On-Board Diagnostics II With VAG 1551". Testing and Inspection