P0118
System
Powertrain (Cooling)
Scanner som krävs
Enhanced OBD2 scanner (live data graphs, freeze frame, battery voltage test)

Engine Coolant Temperature Circuit High Input

Understand P0118, common causes, and the right FOXWELL scanner to diagnose it.

The ECU sees unrealistically high coolant temperature — often a failed ECT sensor, wiring short, or actual overheating.

Vanliga symptom

  • Temperature gauge pegged hot
  • Check engine light
  • Possible limp mode or fan always on

Typiska orsaker

  • Failed ECT sensor
  • Short to voltage in sensor circuit
  • Low coolant causing sensor dry-out
  • Actual engine overheating

Vilken scanner behöver du?

Enhanced OBD2 scanner (live data graphs, freeze frame, battery voltage test)

Använd live-data och freeze frame innan du byter delar. ABS-, SRS- och U-koder kräver oftast en fullsystems-scanner.

Diagnostiktips

  • Spara freeze frame när koden först sätts
  • Rensa koden först efter att orsaken är åtgärdad
  • Kontrollera relaterade väntande koder
  • Verifiera batterispänning över 12,4 V innan du misstänker sensorer

Rekommenderade FOXWELL-scannrar

Vanliga frågor

Can I diagnose P0118 with a basic code reader?
P0118 may set in the engine module, but related diagnostics often benefit from an enhanced or full-system scanner with live data and freeze frame.
Is it safe to drive with P0118?
It depends on the code and symptoms. Flashing check engine lights and misfire codes should be addressed immediately. Consult a professional if unsure.