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P0118

Overview

Code

P0118

Code Type

P

Code Class

P0

System

Engine

Severity Level

Medium

Emissions Related

true

Drivability Impact

Minor

Diagnostic Protocol

OBD2

Freeze Frame Useful

true

Code Definition

Diagnostic trouble code P0118 indicates that the engine coolant temperature sensor signal is higher than the normal operating range detected by the ECM

Symptoms

Check Engine Light illuminated; Hard starting when warm; Poor fuel economy

Overview applies to this diagnostic code.

Affected Systems

On This Page

  • Code Definition

  • Symptoms

  • Affected Systems

  • Possible Causes

  • Diagnostic Steps

  • Drive Safety Notes​

More Resources

High ECT readings can cause improper fuel mixture and cooling system behavior

Possible Causes

Faulty ECT sensor; Open circuit in wiring; Loose electrical connections

Diagnostic Steps

1 Confirm the fault code; 2 Inspect wiring for open circuits; 3 Monitor live coolant temperature data; 4 Compare readings to actual engine temperature; 5 Replace the ECT sensor if readings are incorrect

Drive Safety Notes

Driving is generally safe, but diagnosis is recommended to prevent engine management issues

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