how to fix P0135 code in Volkswagen Golf MK6 (2009-2014)

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative terminal of the battery to ensure safety while working on the electrical system.
• Allow the engine to cool down before starting work.

2. Inspect and Repair Wiring

• Inspect Wiring:

  • Visually check the oxygen sensor wiring harness for fraying or damage.
  • Repair any damaged wires using solder and electrical tape or replace the wiring harness if necessary.

• Reconnect Connectors:

  • Ensure that all connectors are securely attached. Clean any corrosion with electrical contact cleaner.

3. Replace the Upstream Oxygen Sensor

• Remove the Old Sensor:

  • Use an oxygen sensor socket to unscrew the old sensor from the exhaust manifold.
  • Disconnect the wiring harness from the old sensor.

• Install the New Sensor:

  • Apply anti-seize compound to the threads of the new oxygen sensor (if applicable).
  • Screw the new sensor into the exhaust manifold and tighten it to the manufacturer's specifications (typically 30-50 lb-ft).
  • Reconnect the wiring harness to the new sensor.

4. Check and Replace Fuse (if necessary)

• Inspect Fuse:
  • Locate the fuse box and identify the fuse related to the oxygen sensor heater circuit.
  • Remove the fuse and visually check if it is blown. Replace it with a fuse of the same amperage if necessary.

5. Reconnect Battery and Clear Codes

• Reconnect the negative terminal of the battery.
• Use the OBD-II scanner to clear the P0135 code and any other diagnostic trouble codes stored in the vehicle's system.