What are the Possible Causes of the DTC P0118 Cadillac?
NOTE: The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.
Low engine coolant level
Leaking or stuck open thermostat
Faulty Engine Coolant Temperature (ECT) sensor
Engine Coolant Temperature sensor harness is open or shorted
Engine Coolant Temperature sensor electrical circuit poor connection
Faulty Engine Control Module (ECM)
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How to Fix the DTC P0118 Cadillac?
Review the 'Possible Causes' mentioned above and visually examine the corresponding wiring harness and connectors. Ensure to check for any damaged components and inspect the connector pins for signs of being broken, bent, pushed out, or corroded.
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What is the Cost to Diagnose the Code?
Labor: 1.0
To diagnose the P0118 Cadillac code, it typically requires 1.0 hour of labor. The specific diagnosis time and labor rates at auto repair shops can differ based on factors such as the location, make and model of the vehicle, and even the engine type. It is common for most auto repair shops to charge between $75 and $150 per hour.
What are Code Possible Symptoms?
Engine Light ON (or Service Engine Soon Warning Light)
Code P0118 Cadillac Description
The Engine Coolant Temperature (ECT) sensor is a variable resistor that measures the temperature of the engine coolant. The Engine Control Module (ECM) supplies 5 V to the ECT sensor signal circuit and a ground for the low reference circuit.
The ECM uses this high side coolant rationality diagnostic to determine if the input from the ECT sensor is skewed warmer than normal. The internal clock of the ECM will record the amount of time the ignition is OFF. If the calibrated ignition OFF time is met at start-up, the ECM will compare the temperature difference between the ECT and the intake air temperature (IAT) to determine if the temperatures are within an acceptable operating range of each other. The Diagnostic Trouble Code (DTC) will be set when the ECM detects a the ECT is colder than -39°C (-38°F) for greater than 5 s.
P0118 Cadillac Code - Engine Coolant Temperature Circuit High Input
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