The P059F diagnostic trouble code (DTC) is a common issue for 2016 Nissan Altima owners. This code indicates a problem with the engine coolant thermostat heater control circuit, which can lead to poor engine performance, reduced fuel efficiency, and even engine damage. This guide will walk you through diagnosing and resolving the P059F code in your 2016 Nissan Altima.
Understanding the P059F Code
The engine coolant thermostat regulates the engine’s operating temperature. The thermostat heater helps the engine reach optimal temperature faster, improving fuel economy and emissions. The P059F code signifies a fault within the electrical circuit that controls this heater. Common causes include:
- Faulty Thermostat Heater: The heater itself might be damaged or burned out.
- Wiring Issues: Damaged wiring, loose connections, or corroded connectors in the heater circuit can cause the P059F code.
- Coolant Temperature Sensor Problems: A malfunctioning coolant temperature sensor can provide incorrect readings, leading to the code.
- Engine Control Module (ECM) Issues: In rare cases, a faulty ECM might be the culprit.
Diagnosing the P059F Code
Before starting any repairs, it’s crucial to properly diagnose the problem. Here’s a step-by-step approach:
- Retrieve the Code: Use an OBD-II scanner to confirm the P059F code. Other codes might be present, providing further clues.
- Inspect the Thermostat Housing and Wiring: Visually check the thermostat housing for any signs of damage, leakage, or loose connections. Inspect the wiring harness for any obvious damage, fraying, or corrosion.
- Test the Thermostat Heater: Using a multimeter, check the resistance of the thermostat heater. Compare the reading to the manufacturer’s specifications. A reading outside the specified range indicates a faulty heater.
- Check the Coolant Temperature Sensor: Test the coolant temperature sensor’s resistance and voltage output. Again, compare your findings with the manufacturer’s specifications.
- Consult the Factory Service Manual (FSM): Refer to the 2016 Nissan Altima FSM for detailed wiring diagrams, connector pinouts, and specific troubleshooting procedures. The FSM is crucial for accurate diagnosis and repair. Be sure to use the correct year FSM as information can vary between model years.
Repairing the P059F Issue
Once the cause of the P059F code is identified, the necessary repairs can be made:
- Replace the Thermostat: If the thermostat heater is faulty, replacing the entire thermostat assembly is typically the most efficient solution.
- Repair Wiring: Repair or replace any damaged or corroded wiring in the heater circuit. Ensure all connections are secure.
- Replace the Coolant Temperature Sensor: If the sensor is malfunctioning, replace it with a new one.
- Address ECM Issues: If the ECM is suspected to be faulty, consult a qualified technician for diagnosis and repair. This is a complex issue that requires specialized knowledge and equipment.
Conclusion
Addressing the P059F code in your 2016 Nissan Altima is essential for maintaining optimal engine performance and preventing potential damage. By following the diagnostic and repair steps outlined in this guide, you can resolve the issue and ensure your Altima runs smoothly. Always consult the 2016 Nissan Altima FSM for detailed information and specific procedures for your vehicle. Remember to double check the year of the FSM to ensure accuracy. Using the incorrect year’s manual can lead to misdiagnosis and wasted time.
