P0118 — Engine Coolant Temperature Sensor Circuit 1 High Input
Category: Powertrain Severity: Medium
Updated:
DTC code P0118 means: Engine Coolant Temperature Sensor Circuit 1 High Input. It falls under the "Powertrain" category, with an estimated severity of Medium. Common causes include faulty engine coolant temperature (ECT) sensor, low coolant and faulty thermostat; it's worth confirming the diagnosis before replacing parts.
Possible causes
- Faulty engine coolant temperature (ECT) sensor
- Low coolant
- Faulty thermostat
- Wiring/connector issue
Symptoms
- Loss of power when accelerating
- Unstable idle
- Higher fuel consumption
- Jerking while driving
How to diagnose it step by step
- Read coolant temperature: -40 indicates an open circuit.
- Check the sensor connector.
- Check wiring to the ECU.
- Replace the sensor.
How to fix it
Clean or replace the MAF/MAP sensor and check for intake leaks.
Estimated repair cost
$50–150 installed.
Frequently asked questions
What does DTC code P0118 mean?
Engine Coolant Temperature Sensor Circuit 1 High Input.
Is code P0118 serious?
Severity Medium. Not urgent, but worth diagnosing to avoid bigger damage.
Can I keep driving with code P0118?
Carefully, while watching actual engine temperature.
Related codes
P0117 P0116 P0115 P0113 P0112 P0110 P0120 P0121 P0122 P0123
Refine by car make
- Audi P0118: Mass air flow (MAF) sensor or leak.
- BMW P0118: Coolant temperature sensor.
- Citroën P0118: MAF/MAP sensor or leak.
- Dacia P0118: MAF/MAP sensor.
- Fiat P0118: MAF/MAP sensor.
- Ford P0118: ECT sensor or thermostat.
- Honda P0118: MAF/MAP sensor.
- Hyundai P0118: MAF sensor.
- Kia P0118: MAF sensor.
- Mazda P0118: MAF sensor.
- Mercedes-Benz P0118: MAF sensor or intake leak.
- Nissan P0118: MAF sensor.
- Opel P0118: MAF sensor or leak.
- Peugeot P0118: MAF/MAP sensor or leak.
- Renault P0118: MAF/MAP sensor or leak.
- Toyota P0118: ECT sensor.
- Volkswagen P0118: ECT sensor or thermostat.
- Volvo P0118: MAF sensor.
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