Heated Oxygen Sensor Control Test: After Converter

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.

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).




Display Group 116: Display Fields 1-4


Continuation
- 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.
- Increase engine speed to above 3000 RPM.

If the value in display field 3 remains constant.




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 See below.

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: Infinite Ohms.
- Check shielding for short circuit to HO2S wiring.
- Terminal 4 and test box socket 56
- Terminal 3 and test box socket 56
Specification: Infinite 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, Readiness code, creating.