Quick Answer
P059D means: The P059D code indicates a thermostat control circuit issue, affecting engine temperature regulation.
Can I drive with P059D? Immediate attention is recommended to prevent overheating and further damage.
Common Questions
What does P059D mean and how does it affect my car?
The P059D code signifies a thermostat control issue, which can lead to overheating and poor engine performance. If ignored, it may cause severe engine damage over time.
What are the most common causes of P059D and how much does it cost to fix?
Common causes include a faulty thermostat (60% likelihood) and damaged wiring. Repair costs can range from $150 to $300 for thermostat replacement.
Can I drive my car with P059D or should I stop immediately?
Driving with a P059D code is not advisable as it can lead to engine overheating. It's best to address the issue promptly to avoid potential damage.
How can I diagnose P059D myself using GeekOBD APP?
Using the GeekOBD APP, you can scan for codes, view freeze frame data, and perform live parameter monitoring to assess thermostat performance and wiring integrity.
What vehicles are most commonly affected by P059D?
Commonly affected vehicles include the 2016-2019 Ford Explorer and the 2017-2020 Chevrolet Malibu, among others. Check for any recalls or technical service bulletins related to this issue.
How can I prevent P059D from happening again?
Regular maintenance, including coolant checks and replacing the thermostat at recommended intervals, can help prevent future occurrences of the P059D code.
What is P059D?
The DTC P059D code indicates a problem with the thermostat control circuit, specifically when the performance of the thermostat falls outside the expected range. This code often triggers when the engine control module (ECM) detects that the thermostat is not functioning properly, which can lead to engine overheating or excessive fuel consumption. Thermostats are crucial for regulating engine temperature by controlling the flow of coolant. When the thermostat fails to open or close at the correct temperature, it can result in poor engine performance, increased emissions, and potential engine damage. In the real world, drivers may notice that their vehicle’s engine temperature gauge fluctuates abnormally or that the check engine light comes on. Ignoring this code can lead to more serious issues, including overheating, which can be costly to repair. It’s important for owners of affected vehicles, such as the 2016-2019 Ford Explorer or the 2017-2020 Chevrolet Malibu, to address this code promptly to maintain optimal vehicle performance and prevent further damage.
System: P - Powertrain (Engine, Transmission, Emissions)
Symptoms
Common symptoms when P059D is present:
- The check engine light illuminates, often remaining on until the issue is resolved.
- Engine temperature gauge shows fluctuating readings, indicating overheating or underheating.
- Fuel economy decreases, with some drivers reporting a drop of 10-15% due to inefficient engine operation.
- Unusual noises from the engine bay, such as rattling or hissing, which may indicate overheating.
- Engine performance issues, including rough idling or stalling, especially during acceleration.
Possible Causes
Most common causes of P059D (ordered by frequency):
- The most common cause of the P059D code is a faulty thermostat, which has a likelihood of about 60%. A thermostat that sticks open or closed can disrupt engine temperature control.
- Another cause could be damaged wiring or poor connections in the thermostat circuit, which can prevent proper electrical signals from reaching the ECM.
- Coolant leaks can also lead to this code, as low coolant levels may not allow the thermostat to operate effectively. Regularly check coolant levels to prevent this issue.
- Less common but serious causes include a malfunctioning ECM, which may incorrectly interpret the thermostat's performance.
- In rare cases, issues with the engine temperature sensor can trigger the P059D code, though this is less frequently encountered.
P059D Repair Costs
Cost Breakdown by Repair Type
Thermostat Replacement
Replacing a faulty thermostat, including parts and labor costs.
- Total: $150 - $300
- Success rate: 85%
Wiring Repair
Repairing damaged wiring or connections in the thermostat circuit.
- Total: $100 - $200
- Success rate: 75%
Money-Saving Tips for P059D
- Start with the most common and least expensive repairs first
- Use GeekOBD APP to confirm diagnosis before replacing expensive parts
- Consider preventive maintenance to avoid future occurrences
- Compare prices for OEM vs aftermarket parts based on your needs
- Address the issue promptly to prevent more expensive secondary damage
Diagnostic Steps
Professional P059D Diagnosis Process
Follow these systematic steps to accurately diagnose P059D. Each step builds on the previous one to ensure accurate diagnosis.
Step 1: Step 1: Initial visual inspection - Check for obvious signs like damaged wiring, loose connections, or corrosion (5-10 minutes)
Step 1: Initial visual inspection - Check for obvious signs like damaged wiring, loose connections, or corrosion (5-10 minutes).
Step 2: Step 2: OBD2 scan with GeekOBD APP - Retrieve all codes and freeze frame data to understand the fault context (10-15 minutes)
Step 2: OBD2 scan with GeekOBD APP - Retrieve all codes and freeze frame data to understand the fault context (10-15 minutes).
Step 3: Step 3: Component testing - Use a multimeter or specific diagnostic tools to test the thermostat and its circuit (20-30 minutes)
Step 3: Component testing - Use a multimeter or specific diagnostic tools to test the thermostat and its circuit (20-30 minutes).
Step 4: Step 4: System function test - Verify proper operation after repairs and clear codes (10-15 minutes)
Step 4: System function test - Verify proper operation after repairs and clear codes (10-15 minutes).
Step 5: Step 5: Road test verification - Drive the vehicle under various conditions to confirm repair success (15-20 minutes)
Step 5: Road test verification - Drive the vehicle under various conditions to confirm repair success (15-20 minutes).
Important Notes
- Always verify the repair with GeekOBD APP after completing diagnostic steps
- Clear codes and test drive to ensure the problem is resolved
- Address underlying causes to prevent code recurrence
Real Repair Case Studies
Case Study 1: Thermostat Replacement on 2017 Chevrolet Malibu
Vehicle: 2017 Chevrolet Malibu, 45,000 miles
Problem: Customer reported check engine light and fluctuating engine temperature.
Diagnosis: Diagnostic scan revealed P059D code. Visual inspection showed a faulty thermostat.
Solution: Replaced the thermostat and gasket. Cleared the code and performed system checks.
Cost: $250 (parts: $60, labor: $190)
Result: Customer reported improved performance and no more check engine light.
Case Study 2: Wiring Repair on 2018 Ford Explorer
Vehicle: 2018 Ford Explorer, 30,000 miles
Problem: Vehicle overheating and check engine light on.
Diagnosis: P059D was retrieved. Inspected wiring and found damaged connectors.
Solution: Repaired wiring and replaced connectors. Cleared the code and conducted tests.
Cost: $150 (parts: $40, labor: $110)
Result: No further issues reported. Engine operated within normal temperature range.