P0115High Priority

Engine Coolant Temperature Circuit Malfunction

Category: PowertrainFuel and Air Metering

Reference page

What is P0115?

Engine Coolant Temperature (ECT) Sensor Circuit Malfunction. Problem with the coolant temperature sensor circuit, affecting cold start enrichment and thermostat monitoring.

Symptoms You May Notice

  • Check engine light
  • Poor fuel economy
  • Hard starting when cold
  • Cooling fan always on
  • No heat from heater

How to Fix It

  • Replace ECT sensor ($50-$150, beginner)
  • Repair wiring harness ($100-$300, intermediate)
  • Check coolant level ($0-$50, beginner)

Owner Statistics

Based on 17,515 real owner discussions • 356 confirmed solutions

Dataset (17,515 records)
$12,703
Average Repair Cost
2%
Success Rate

About This Data

Statistics are aggregated from real owner discussions on Reddit, automotive forums, and YouTube comments. All data is anonymized and represents actual repair experiences reported by vehicle owners.

Issues by Vehicle

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Reference Information Only

This is a general OBD-II code reference. We're actively collecting real owner experiences and repair data for this code. Check back soon for vehicle-specific troubleshooting guides.