P0598 - Thermostat Control Circuit Range/Performance Problem in Vehicles Like Honda Accord and Toyota Camry

Quick Answer

P0598 means: P0598 indicates a problem with the thermostat control circuit's performance, affecting engine temperature regulation.

Fix: Check and replace faulty components Cost: $150 - $350 Time: 90-180 minutes

Can I drive with P0598? It's advisable to diagnose and repair this issue promptly to prevent engine overheating.

Common Questions

What does P0598 mean and how does it affect my car?

P0598 indicates that there's an issue with your vehicle's thermostat control circuit. This can cause your engine to overheat or run too cold, affecting fuel efficiency and possibly leading to engine damage. If ignored, it could result in costly repairs down the line.

What are the most common causes of P0598 and how much does it cost to fix?

Common causes include a faulty thermostat, malfunctioning ECM, and wiring issues. Repair costs typically range from $150 to $500 depending on the specific issue and whether parts need replacement.

Can I drive my car with P0598 or should I stop immediately?

While it's possible to drive with the P0598 code, it's not recommended. Continued driving can lead to overheating and serious engine damage. It's best to address this issue as soon as possible.

How can I diagnose P0598 myself using GeekOBD APP?

To diagnose P0598 using the GeekOBD APP, connect the app to your vehicle's OBD2 port, retrieve the trouble codes, and check the live data for the thermostat's operation. Look for any inconsistencies in temperature readings.

What vehicles are most commonly affected by P0598?

Vehicles like the 2015-2018 Honda Accord and 2016-2019 Toyota Camry frequently experience the P0598 code. Always check for any manufacturer recalls or technical service bulletins related to thermostat issues.

How can I prevent P0598 from happening again?

Regular maintenance of your cooling system, including timely coolant changes and inspections of the thermostat and related components, can help prevent P0598 from recurring.

What is P0598?

The P0598 diagnostic trouble code (DTC) indicates a thermostat control circuit range/performance problem. This code typically arises when the Engine Control Module (ECM) detects that the thermostat is not functioning correctly within the expected range. The thermostat plays a crucial role in regulating engine temperature by controlling the flow of coolant to the engine. When the thermostat fails to open or close as it should, it can lead to overheating or underheating of the engine, which can create a host of performance issues. Commonly found in vehicles such as the 2015-2018 Honda Accord and the 2016-2019 Toyota Camry, this issue can lead to decreased fuel economy, increased emissions, and potential engine damage if not addressed promptly. Ignoring this code could lead to serious engine complications, as the improper temperature regulation can affect everything from fuel efficiency to engine longevity. Therefore, it’s crucial for car owners to understand this code and take appropriate measures to diagnose and rectify the problem. Regular maintenance and timely repairs are essential to ensure the thermostat and its circuit function properly.

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

Symptoms

Common symptoms when P0598 is present:

  • The check engine light illuminates and remains on, indicating a need for immediate attention.
  • Engine performance issues such as hesitation or stalling during acceleration, which may be noticeable during highway driving.
  • A significant decrease in fuel economy, potentially around 10-15%, which can add up in fuel costs over time.
  • Overheating engine, which could lead to severe engine damage if not addressed quickly.
  • Unusual coolant smell or leaks around the thermostat housing area, indicating possible failures in the cooling system.

Possible Causes

Most common causes of P0598 (ordered by frequency):

  1. The most common cause is a faulty thermostat, which may occur in approximately 60% of cases. This can happen due to wear and tear or debris blocking the thermostat.
  2. A malfunctioning Engine Control Module (ECM) is another possibility, accounting for about 20% of P0598 codes. This can occur due to software glitches or electrical issues.
  3. Wiring issues or poor connections in the thermostat control circuit can lead to P0598, representing about 15% of cases. Regular inspections can help prevent these issues.
  4. Less common but serious causes include a defective coolant temperature sensor, which can mislead the ECM about the engine's temperature.
  5. In rare cases, a complete failure of the cooling system, such as a broken water pump, could cause the thermostat to behave erratically, but this is infrequent.

P0598 Repair Costs

Cost Breakdown by Repair Type

Thermostat Replacement

Replacing the faulty thermostat with a new unit to restore proper engine temperature regulation.

  • Total: $150 - $350
  • Success rate: 95%
Wiring Repair

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

  • Total: $100 - $200
  • Success rate: 85%
ECM Reprogramming

Reprogramming the Engine Control Module if it is found to be faulty.

  • Total: $200 - $500
  • Success rate: 90%
Money-Saving Tips for P0598
  • 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 P0598 Diagnosis Process

Follow these systematic steps to accurately diagnose P0598. 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 in the thermostat control circuit (5-10 minutes)

Step 1: Initial visual inspection - Check for obvious signs like damaged wiring, loose connections, or corrosion in the thermostat control circuit (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 check for any related codes (10-15 minutes)

Step 2: OBD2 scan with GeekOBD APP - Retrieve all codes and freeze frame data to understand the fault context and check for any related codes (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 measure voltage and resistance at the thermostat and its connectors to diagnose failures (20-30 minutes)

Step 3: Component testing - Use a multimeter to measure voltage and resistance at the thermostat and its connectors to diagnose failures (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 - Verify proper operation of the thermostat after repairs and clear codes using the GeekOBD APP (10-15 minutes)

Step 4: System function test - Verify proper operation of the thermostat after repairs 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 ensure that the P0598 code does not return and that the engine maintains a consistent temperature (15-20 minutes)

Step 5: Road test verification - Drive the vehicle under various conditions to ensure that the P0598 code does not return and that the engine maintains a consistent temperature (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 for 2016 Honda Accord

Vehicle: 2016 Honda Accord, 45,000 miles

Problem: Customer reported check engine light on with symptoms of engine overheating.

Diagnosis: Used GeekOBD APP to retrieve DTC P0598 and perform a component test revealing a faulty thermostat.

Solution: Replaced the faulty thermostat with an OEM part, cleared the codes, and verified proper operation.

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

Result: Post-repair road test showed normal engine temperature and no return of the P0598 code.

Case Study 2: Wiring Repair for 2017 Toyota Camry

Vehicle: 2017 Toyota Camry, 30,000 miles

Problem: Customer experienced check engine light and reduced fuel efficiency.

Diagnosis: Diagnostic scan revealed P0598. Visual inspection showed damaged wiring in the thermostat circuit.

Solution: Repaired the damaged wiring and reconnected the circuit.

Cost: $180 (parts: $30, labor: $150)

Result: After the repair, the vehicle’s performance improved significantly, and the check engine light remained off.

Diagnose P0598

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: P0598
System: Powertrain (Engine, Transmission, Emissions)
Severity: HIGH
Category: Engine Codes