Quick Answer
P059C means: The P059C code indicates a problem with the thermostat control circuit performance, affecting engine temperature regulation.
Can I drive with P059C? Immediate attention is recommended to prevent potential engine damage.
Common Questions
What does P059C mean and how does it affect my car?
The P059C code indicates a thermostat control circuit issue, which can lead to improper engine temperatures, affecting performance and fuel efficiency. If unresolved, it could cause serious engine damage.
What are the most common causes of P059C and how much does it cost to fix?
Common causes include a faulty thermostat, wiring issues, or a malfunctioning ECM. Repair costs can vary widely, typically ranging from $150 to $600 depending on the specific problem and repair needed.
Can I drive my car with P059C or should I stop immediately?
It's not advisable to drive your vehicle with this code, especially if you notice symptoms like overheating, as this could lead to severe engine damage.
How can I diagnose P059C myself using GeekOBD APP?
To diagnose P059C, use the GeekOBD APP to scan for trouble codes and monitor live data from the thermostat. Look for temperature readings and response times to assess if the thermostat is functioning correctly.
What vehicles are most commonly affected by P059C?
This code is frequently seen in 2016-2020 Chevrolet Malibu, 2015-2018 Buick Regal, and some 2014-2019 GMC Acadia models, among others. Always check for recalls or technical service bulletins related to these issues.
How can I prevent P059C from happening again?
Regular maintenance, including coolant system flushes and inspections of the thermostat and wiring, can help prevent recurrence. Keeping an eye on temperature gauge readings can also alert you to potential issues early.
What is P059C?
The P059C diagnostic trouble code (DTC) indicates that there's a performance issue with the thermostat control circuit in your vehicle. This code commonly appears in models such as the 2016-2020 Chevrolet Malibu and other GM vehicles. The thermostat plays a crucial role in regulating the engine's temperature by controlling the flow of coolant. When the engine control module (ECM) detects that the thermostat is not operating within its specified range or is malfunctioning, it triggers the P059C code. This can result in the engine running too hot or too cold, leading to reduced performance and increased emissions. Symptoms like poor fuel economy, engine overheating, or fluctuating temperature gauges may occur. Ignoring this code can result in serious engine damage over time, as the engine may not maintain optimal operating temperatures. Therefore, addressing the P059C code promptly is essential for maintaining vehicle performance and longevity.
System: P - Powertrain (Engine, Transmission, Emissions)
Symptoms
Common symptoms when P059C is present:
- The check engine light is illuminated, indicating a malfunction in the engine management system.
- You may notice that the engine takes longer than usual to reach optimal operating temperature, affecting performance.
- Fuel economy could decrease by 10-20%, resulting in increased trips to the gas station.
- The temperature gauge may fluctuate unexpectedly, indicating irregular cooling system performance.
- In some cases, you might experience engine overheating, which can lead to serious damage if not addressed.
Possible Causes
Most common causes of P059C (ordered by frequency):
- The most common cause of the P059C code is a faulty thermostat, which accounts for about 60% of cases. A stuck-open or stuck-closed thermostat can disrupt the engine's temperature regulation.
- Another potential cause is wiring issues within the thermostat control circuit, such as damaged wires or poor connections, which can prevent the proper signals from reaching the ECM.
- The third common cause is a malfunctioning engine control module (ECM), which may misinterpret the thermostat's performance due to software glitches or internal errors.
- Less commonly, a coolant leak could lead to insufficient coolant levels, affecting the thermostat's ability to operate correctly.
- A rare cause may involve contamination within the cooling system, such as rust or debris, which can impede the thermostat's function.
P059C Repair Costs
Cost Breakdown by Repair Type
Thermostat Replacement
Replacing the faulty thermostat and flushing the cooling system to ensure optimal performance.
- Total: $150 - $300
- Success rate: 90%
Wiring Repair
Repairing or replacing damaged wiring in the thermostat control circuit.
- Total: $50 - $150
- Success rate: 85%
ECM Reprogramming
If the ECM is at fault, it may require reprogramming or replacement.
- Total: $200 - $600
- Success rate: 75%
Money-Saving Tips for P059C
- 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 P059C Diagnosis Process
Follow these systematic steps to accurately diagnose P059C. Each step builds on the previous one to ensure accurate diagnosis.
Step 1: Step 1: Conduct an initial visual inspection to check for obvious signs like damaged wiring, loose connections, or corrosion (5-10 minutes)
Step 1: Conduct an initial visual inspection to check for obvious signs like damaged wiring, loose connections, or corrosion (5-10 minutes).
Step 2: Step 2: Use an OBD2 scanner, like the GeekOBD APP, to retrieve all diagnostic trouble codes and freeze frame data, which helps understand the fault context (10-15 minutes)
Step 2: Use an OBD2 scanner, like the GeekOBD APP, to retrieve all diagnostic trouble codes and freeze frame data, which helps understand the fault context (10-15 minutes).
Step 3: Step 3: Perform component testing on the thermostat and related sensors using a multimeter to check for proper resistance and functionality (20-30 minutes)
Step 3: Perform component testing on the thermostat and related sensors using a multimeter to check for proper resistance and functionality (20-30 minutes).
Step 4: Step 4: Conduct a system function test to verify proper operation of the thermostat after any repairs and clear the codes from the ECM (10-15 minutes)
Step 4: Conduct a system function test to verify proper operation of the thermostat after any repairs and clear the codes from the ECM (10-15 minutes).
Step 5: Step 5: Complete a road test under various driving conditions to confirm the repair and ensure that the P059C code does not reappear (15-20 minutes)
Step 5: Complete a road test under various driving conditions to confirm the repair and ensure that the P059C code does not reappear (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 2018 Chevrolet Malibu
Vehicle: 2018 Chevrolet Malibu, 45,000 miles
Problem: The owner noticed the check engine light was on and the engine was running cooler than normal.
Diagnosis: After scanning the vehicle with the GeekOBD APP, the P059C code was confirmed. A visual inspection revealed a faulty thermostat.
Solution: The thermostat was replaced, and the cooling system was flushed to remove any debris.
Cost: $250 (parts: $100, labor: $150)
Result: The check engine light was cleared, and the vehicle returned to normal operating temperatures without further issues.
Case Study 2: Wiring Repair on 2017 Buick Regal
Vehicle: 2017 Buick Regal, 60,000 miles
Problem: The driver experienced erratic temperature readings on the dashboard.
Diagnosis: Diagnostic testing revealed a P059C code due to damaged wiring in the thermostat circuit.
Solution: The damaged wiring was repaired, and the system was tested for proper function.
Cost: $120 (parts: $20, labor: $100)
Result: The temperature readings stabilized, and the check engine light remained off after the repair.