Error code

OBD2 P0115

OBD2P0115
Diagnostic Trouble Code· Standard OBD-II fault code read from the vehicle's onboard diagnostics.

What it means

Engine Coolant Temperature Circuit.

Severity

moderateCan drive but monitor the issue closely. Engine overheating can occur if not addressed.

Summary

P0115 indicates a malfunction in the engine coolant temperature (ECT) sensor circuit. This issue affects the PCM's ability to accurately monitor and regulate engine temperature.

Common Causes

  • Burnt, damaged, shorted, or corroded wiring and connectors
  • Defective coolant temperature sensors
  • Low engine coolant levels
  • Poor coolant circulation
  • Failed or failing PCM

Diagnosis

  1. Inspect and test wiring for damage, corrosion, or shorts.
  2. Check coolant levels and circulation issues.
  3. Test sensors for proper resistance values using a temperature to resistance chart.
  4. Verify radiator fan operation after repairs.

Fixes

  • Replace faulty ECT sensor(s) if necessary

FAQ

What should I do if my car has P0115?

Inspect the wiring and coolant levels first. If issues persist, test the ECT sensors for proper resistance values.

Can a bad PCM cause this code?

A failed or failing PCM can cause P0115, but it's rare compared to other causes like faulty wiring or sensors.

View source

Not affiliated with OBD2. Answer summarized from the manufacturer's manual linked above; consult that source for the authoritative procedure.

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