Engine-Codes - Generic - P1118

P1118 - Engine Coolant Temp Signal Out-Of Range High

Repair Importance Level: 3/3
Repair Difficulty Level: 2/3  What is this?
Table of contents

P1118 Possible Causes

  • Faulty Engine Coolant Temperature (ECT) sensor
  • Low engine coolant level
  • Engine Coolant Temperature (ECT) sensor harness is open or shorted
  • Engine Coolant Temperature (ECT) sensor electrical circuit poor connection
  • Faulty engine coolant thermostat

How is the P1118 code repair?

Start by checking the "Possible Causes" listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector's pins.

What is the cost to diagnose the P1118 code

Labor: 1.0

The cost to diagnose the P1118 code is 1.0 hour of labor. The auto repair labor rates vary widely across the country, and even within the same city. Most auto repairs shops charge between $75 and $150 per hour.

Possible Symptoms

  • Engine Light ON (or Service Engine Soon Warning Light)

P1118 Meaning

The Engine Coolant Temperature (ECT) sensor contains a semiconductor device which changes resistance based on temperature (a thermistor). The ECT sensor mounts in the left bank cylinder head near the front of the engine. The ECT sensor has a signal circuit and a ground circuit. The PCM applies a voltage (about 5.0 volts) on the signal circuit to the sensor. The PCM monitors changes in this voltage caused by changes in the resistance of the sensor in order to determine the engine coolant temperature.
When the engine coolant is cold, the sensor (thermistor) resistance is high, and the PCMs signal voltage is only pulled down a small amount through the sensor to ground. The PCM senses a high signal voltage (low temperature). When the engine coolant is warm, the sensor resistance is low, and the signal voltage is pulled down a greater amount. This causes the PCM to sense a low signal voltage (high temperature).

More Information

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Information for specific makes

  • P1118 AUDI HO2S Sensor Heater Circuit Open Bank 1 Sensor 2
  • P1118 BMW Mass Or Volume Air Flow Circuit High Input Bank 2
  • P1118 BUICK Engine Coolant Temp Signal Out-Of Range High
  • P1118 CADILLAC Engine Coolant Temp Signal Out-Of Range High
  • P1118 CHEVROLET Engine Coolant Temp. Signal Out-Of-Range High
  • P1118 FORD Manifold Absolute Temperature Circuit Low Input
  • P1118 GMC Engine Coolant Temp. Signal Out-Of-Range High
  • P1118 HYUNDAI Electronic Throttle System Motor Malfunction
  • P1118 LAND-ROVER Thermostat Monitoring Sensor Open Circuit Or Short Circuit To Battery
  • P1118 LEXUS Coolant Temperature Sensor Circuit High for Coolant Heat Storage System
  • P1118 MINI Mass Or Volume Air Flow Circuit High Input Bank 2
  • P1118 SCION Coolant Temperature Sensor Circuit High for Coolant Heat Storage System
  • P1118 TOYOTA Coolant Temperature Sensor Circuit High for Coolant Heat Storage System
  • P1118 VOLKSWAGEN HO2S Sensor Heater Circuit Open Bank 1 Sensor 2

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