P0115 - Engine Coolant Temperature Circuit Malfunction

Problem detected in ECT sensor circuit.

Treat the code as the starting point: compare symptoms, likely causes, and repair paths before pricing parts or moving into an estimate.

Code Overview

Problem detected in ECT sensor circuit.

Common Causes

• ECT sensor failed
• Wiring/connectors issue
• Low coolant/air pockets (can skew readings)

Diagnostic Steps

1. Compare ECT to ambient when cold
2. Inspect connector for coolant intrusion
3. Bleed cooling system if needed

Likely Repairs & Cost Guides

Use symptoms, scan data, and quick checks to confirm the likely repair path before pricing parts. The estimator helps compare repair paths before replacing anything unnecessarily.

Related OBD Codes

Browse nearby code-family pages when the same fault pattern overlaps across systems, such as misfire, lean fuel trim, EVAP sealing, cooling, or charging faults.

Next Steps

Move from code lookup to diagnosis, then estimate the likely repair only after symptoms, causes, and checks point to the same path.