Basic and Visual Checks

SERVICE

Note
All Repair Manual references refer to 04/94 Edition

Follow these steps to avoid unnecessary repairs when diagnosing suspected HO2S problems

Make sure you have enough information

1. What is the symptom?

2. Under what conditions does it occur?

3. Is this the first repair for this complaint?

4. Has any other work been recently performed on the car?


BASIC AND VISUAL CHECKS

5. Check wires for slack. Check ground connections. Make sure all harnesses are stress free and wire insulation is not brittle and does not hide broken wires. If necessary perform voltage drop tests to verify connections.

6. Check system for vacuum and air leaks.

^ VAG 1551 Scan Tool Procedure Remember turn printer on and print ECM version, Diagnostic Trouble Codes (DTC's) and measuring block values.

Read stored DTC's, observe block values, and verify customer complaint.

Follow VAG 1551 connection and DTC memory check and erasing as described in the Golf III GTI, Jetta III, Cabrio 2.0 Liter Fuel Injection & Ignition Repair Manual.

Refer to sections 01-11 through 01-24 for DTC table.

If a DTC exists, perform prescribed repairs, erase DTC memory and verify repair.




If complaint still exists perform the following tests:

^ Insure that brown/red wire and the red/white wires of the harness match up to the white wires of the Oxygen sensor heater connector.

^ Perform a resistance test on the heating element to verify that the heater element resistance is approximately 2 Ohms.