Several things can cause this code:
* Faulty HO2S Heater Element: The most common cause. The heater element itself has burned out or is failing. This is often due to age and wear.
* Wiring Problems: A break, short, or poor connection in the wiring harness leading to the sensor can prevent the heater from receiving power. This includes the wiring itself, the connector at the sensor, or even a problem in the PCM (Powertrain Control Module) harness.
* PCM (Powertrain Control Module) Issue: Though less common, a faulty PCM can fail to supply power to the HO2S heater circuit. This is typically diagnosed by process of elimination after checking the sensor and wiring.
* Relay Problem: Some vehicles use a relay for the HO2S heater circuits. A failing relay could prevent power from reaching the sensor.
* Grounding Issues: A poor ground connection can also prevent the sensor heater from working properly.
Troubleshooting Steps (in order of easiest to hardest):
1. Inspect the wiring harness: Carefully examine the wiring leading to Bank 2, Sensor 1 for any obvious damage, breaks, or corrosion. Pay close attention to the connector at the sensor.
2. Check the HO2S: While more involved, replacing the sensor itself is often the solution. It's relatively inexpensive and easy to replace if you are comfortable working on your vehicle.
3. Check for power and ground at the sensor connector: Use a multimeter to verify that the correct voltage and ground are reaching the sensor's connector. This requires a wiring diagram to identify the appropriate wires.
4. Inspect the relay (if applicable): If your vehicle uses a relay for the HO2S heaters, check its operation.
5. Inspect the ground: Locate the ground connection for the sensor and verify that it's clean and secure.
6. Diagnose the PCM: This is the most complex step and usually requires specialized equipment and knowledge. If all other checks are fine, it's likely time to consult a mechanic.
Before replacing any parts, make sure you double-check your vehicle's specific sensor location. A wiring diagram specific to your 2002 Ford Taurus will be very helpful during this troubleshooting process. Remember to clear the diagnostic trouble code (DTC) after making repairs to verify the problem is resolved.
