P0590 - Thermostat Control Circuit Issue in Ford, Chevrolet, and Dodge Models

Quick Answer

P0590 means: The P0590 code indicates an issue with the thermostat control circuit, which may affect engine temperature regulation.

Fix: Check and replace faulty components Cost: $150 - $300 Time: 90-180 minutes

Can I drive with P0590? It's crucial to address this issue promptly to prevent potential engine damage.

Common Questions

What does P0590 mean and how does it affect my car?

The P0590 code indicates a thermostat control circuit issue, which can lead to overheating and reduced fuel efficiency. If not fixed, it may cause serious engine damage over time, affecting your vehicle's performance and longevity.

What are the most common causes of P0590 and how much does it cost to fix?

Common causes include a faulty thermostat, damaged wiring, or a malfunctioning ECM. Repair costs can range from $150 to $300 for thermostat replacement, while wiring repairs may cost between $100 and $200.

Can I drive my car with P0590 or should I stop immediately?

It is advisable to stop driving your vehicle if you see the P0590 code, as continuing to drive can lead to overheating and severe engine damage. It's best to address this issue as soon as possible.

How can I diagnose P0590 myself using GeekOBD APP?

To diagnose P0590, connect your GeekOBD APP to the vehicle's OBD2 port, retrieve the trouble codes, and check for any freeze frame data. This will give you insight into the conditions leading to the fault, helping you identify the problem.

What vehicles are most commonly affected by P0590?

P0590 is often found in 2015-2020 models from Ford, Chevrolet, and Dodge. It's essential to check for any recalls or Technical Service Bulletins (TSBs) that may address this issue for specific models.

How can I prevent P0590 from happening again?

Regular maintenance, including coolant flushes and inspections of the thermostat and wiring, can help prevent the P0590 code from occurring again. Keeping an eye on engine temperatures and addressing any warning lights promptly is also crucial.

What is P0590?

The P0590 diagnostic trouble code (DTC) indicates a problem within the thermostat control circuit, typically related to the engine's cooling system. When the Engine Control Module (ECM) detects an inconsistency in the signal from the thermostat, it triggers this code. This could mean the thermostat isn't opening or closing correctly, which can lead to overheating or inefficient engine operation. Vehicles affected include various models from Ford, Chevrolet, and Dodge, particularly those made between 2015 and 2020. If the thermostat fails to regulate the engine temperature, you could experience poor fuel economy, reduced engine performance, and even engine damage over time. Typically, the P0590 code is accompanied by other codes related to the cooling system or temperature sensors, making it essential to conduct a thorough diagnostic to pinpoint the exact issue. Ignoring this code can lead to increased emissions and expensive repairs down the line, as prolonged overheating can damage engine components, leading to costly repairs.

System: P - Powertrain (Engine, Transmission, Emissions)

Symptoms

Common symptoms when P0590 is present:

  • Check engine light illuminates and stays on, indicating a potential issue with the engine's cooling system.
  • Engine overheating occurs, which can lead to performance issues and possible engine failure if not addressed.
  • Increased fuel consumption due to the engine operating inefficiently, which may drop fuel economy by 10-20%.
  • Heater performance is poor, especially during winter months, as the engine may not reach the optimal operating temperature.
  • Thermostat housing or coolant leaks may be noticeable around the engine if the thermostat has failed.

Possible Causes

Most common causes of P0590 (ordered by frequency):

  1. The most common cause of the P0590 code is a faulty thermostat, with a likelihood percentage of 60%. This can prevent the thermostat from opening or closing properly.
  2. A damaged thermostat control circuit could lead to signal failures, with about a 25% chance of occurring. Issues in the wiring or connections can disrupt communication between the thermostat and ECM.
  3. Corrosion or poor connections at the thermostat connector can cause intermittent issues, roughly 10% likelihood. Regular maintenance can help prevent this problem.
  4. Less common, but serious, is a malfunctioning ECM, which can misinterpret the signals from the thermostat, leading to a 5% chance of failure.
  5. Rarely, a failed temperature sensor may also cause this code, which could mislead the ECM regarding engine temperature.

P0590 Repair Costs

Cost Breakdown by Repair Type

Thermostat Replacement

Replacing the faulty thermostat and ensuring all connections are secure.

  • Total: $150 - $300
  • Success rate: 85%
Wiring Repair

Repairing or replacing damaged wires or connectors in the thermostat control circuit.

  • Total: $100 - $200
  • Success rate: 70%
Money-Saving Tips for P0590
  • 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 P0590 Diagnosis Process

Follow these systematic steps to accurately diagnose P0590. 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 around the thermostat and related circuitry (5-10 minutes)

Step 1: Initial visual inspection - Check for obvious signs like damaged wiring, loose connections, or corrosion around the thermostat and related circuitry (5-10 minutes).

GeekOBD APP Tip: Use GeekOBD APP to monitor real-time data during this diagnostic step for accurate results and professional-grade analysis.
Step 2: Step 2: OBD2 scan with GeekOBD APP - Retrieve all codes and freeze frame data to understand the fault context and any related issues (10-15 minutes)

Step 2: OBD2 scan with GeekOBD APP - Retrieve all codes and freeze frame data to understand the fault context and any related issues (10-15 minutes).

GeekOBD APP Tip: Use GeekOBD APP to monitor real-time data during this diagnostic step for accurate results and professional-grade analysis.
Step 3: Step 3: Component testing - Use a multimeter to test the thermostat and its control circuit for continuity and resistance (20-30 minutes)

Step 3: Component testing - Use a multimeter to test the thermostat and its control circuit for continuity and resistance (20-30 minutes).

GeekOBD APP Tip: Use GeekOBD APP to monitor real-time data during this diagnostic step for accurate results and professional-grade analysis.
Step 4: Step 4: System function test - After repairs, verify the proper operation of the thermostat and clear codes using the GeekOBD APP (10-15 minutes)

Step 4: System function test - After repairs, verify the proper operation of the thermostat and clear codes using the GeekOBD APP (10-15 minutes).

GeekOBD APP Tip: Use GeekOBD APP to monitor real-time data during this diagnostic step for accurate results and professional-grade analysis.
Step 5: Step 5: Road test verification - Drive the vehicle under various conditions to confirm repair success and monitor temperature gauge behavior (15-20 minutes)

Step 5: Road test verification - Drive the vehicle under various conditions to confirm repair success and monitor temperature gauge behavior (15-20 minutes).

GeekOBD APP Tip: Use GeekOBD APP to monitor real-time data during this diagnostic step for accurate results and professional-grade analysis.

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 in a 2017 Ford F-150

Vehicle: 2017 Ford F-150, 45,000 miles

Problem: Customer reported the check engine light was on and experienced occasional overheating.

Diagnosis: Scanned for codes using the GeekOBD APP, which returned P0590 along with P0128. Visual inspection revealed a faulty thermostat.

Solution: Replaced the thermostat and performed a coolant flush to ensure proper operation.

Cost: $250 (parts: $150 for thermostat, $100 for labor)

Result: Post-repair, the vehicle operated normally with no further overheating issues.

Case Study 2: Wiring Repair on a 2018 Chevrolet Silverado

Vehicle: 2018 Chevrolet Silverado, 30,000 miles

Problem: The check engine light was on, and the vehicle was running poorly with poor fuel economy.

Diagnosis: Using the GeekOBD APP, the P0590 code was logged. A visual inspection showed damaged wiring near the thermostat connector.

Solution: Repaired the damaged wiring and cleared the codes, ensuring all connections were secure.

Cost: $120 (parts: $20 for connectors, $100 for labor)

Result: The vehicle's performance improved significantly, and the check engine light remained off.

Diagnose P0590

Use GeekOBD APP for professional diagnosis!

  • Real-time data monitoring
  • Advanced diagnostic features
  • Step-by-step repair guidance
  • Professional-grade analysis
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Code Information

Code: P0590
System: Powertrain (Engine, Transmission, Emissions)
Severity: HIGH
Category: Engine Codes