Heated Oxygen Sensor (HO2S) G39 , Checking Audi TT 8N

Note. Use only gold-plated terminals when servicing terminals in the electrical harness connectors of the Heated Oxygen Sensor (HO2S) G39.

Special tools, testers and auxiliary items required

1. Multimeter.
2. Wiring diagram.

Test requirements

1. Fuse S243 OK.
2. Motronic Engine Control Module (ECM) J220 fuses OK.
3. Battery voltage at least 12.5 volts.
4. All electrical consumers such as, lights and rear window defroster, switched off.

1. Vehicles with automatic transmission, shift selector lever into position "P" or "N".
2. A/C switched off.
3. Ground (GND) connections between engine/transmission/chassis OK.
4. Ignition switched off.

Test procedure

1. Perform a preliminary check to verify the customers complaint. Refer to --> «General Diagnosis»(ref-276276-S40851803372008010300000) .

Start diagnosis

1. Perform the function test in Diagnostic Mode 06. Refer to --> «Diagnostic Mode 6: Checking Test Results of Components that are not Continuously Monitored»(ref-276276-S13057650312008010300000) .

If specified values are obtained

1. End diagnosis and switch the ignition off.

If the specified values are not obtained

Checking primary voltage

1. Disconnect the Heated Oxygen Sensor (HO2S) G39 electrical harness connector - 2 -.

1. Using a multimeter , check the Heated Oxygen Sensor (HO2S) G39 electrical harness connector terminals 1 to 5 for voltage.

Specified value: 0.400 to 0.500 Volts

1. Switch the ignition off.

If the specified value was not obtained

1. Replace the Heated Oxygen Sensor (HO2S) G39. Refer to --> «24 MULTIPORT FUEL INJECTION (MFI)»(ref-276275-S13244009452008010300000) .

If the specified value was obtained

Checking wiring

If the manufacturers test box is being used. Perform the following step.

1. Install the test box VAG1598/31. Refer to --> «24 MULTIPORT FUEL INJECTION (MFI)»(ref-276275-S13244009452008010300000) .

If the manufacturers test box is not being used. Perform the following step.

1. Remove the Motronic Engine Control Module (ECM) J220. Refer to --> «Motronic Engine Control Module (ECM) J220, Replacing»(ref-276276-S39982482672008010300000) .

1. Using a Multimeter , check the Heated Oxygen Sensor (HO2S) G39 electrical harness connector terminals to the Motronic Engine Control Module (ECM) J220 electrical harness connector terminals for resistance.

Specified value: 1.5 ohms Max.

If the specification was not obtained

1. Check the wiring for a short circuit to each other, Battery (+), and Ground (GND).
2. Check the electrical harness connector for damage, corrosion, loose or broken terminals.
3. If necessary, repair the faulty wiring connection.

If no malfunction is found in the wiring

1. Erase the DTC memory. Refer to --> «Diagnostic Mode 04: Reset/Delete Diagnostic Data»(ref-276276-S31279847122008010300000) .
2. Perform a road test to verify repair.

If the DTC does not return

Repair complete, Generate readiness code. Refer to --> Readiness Code .

1. End diagnosis.

If the DTC does return and no malfunction is detected in the wiring and the voltage supply was OK

1. Replace the Motronic Engine Control Module (ECM) J220. Refer to --> «Motronic Engine Control Module (ECM) J220, Replacing»(ref-276276-S39982482672008010300000) .
2. Assembly is performed in the reverse of the removal.

Final procedures

After repair work, the following work steps must be performed in the following sequence

1. Check the DTC memory.
2. If necessary, erase the DTC memory. Refer to «Diagnostic Mode 04: Reset/Delete Diagnostic Data»(ref-276276-S31279847122008010300000) .
3. If the DTC memory was erased, generate readiness code. Refer to «Readiness Code»(ref-276276-S05799074302008010300000) .

End of diagnosis