Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
This code means that the sensor that checks how hot or cold your car's engine is, isn't working right. It's like a thermometer for the engine, and it's showing a really low temperature, which is unusual.
The P0117 code is triggered when the Engine Control Module (ECM) detects a low voltage signal from the Engine Coolant Temperature (ECT) sensor, indicating a temperature reading lower than normal operating range.
The ECT sensor is a thermistor that changes resistance with temperature changes. A low circuit signal indicates that the sensor is reading a temperature that is too low, which may result from a short circuit, faulty sensor, or wiring issues.
• Check Engine Light illuminated
• Poor fuel economy
• Engine running rough
• Faulty ECT sensor
• Short circuit in the sensor wiring
• Poor electrical connection at the ECT sensor
ECT: Engine Coolant Temperature
ECM: Engine Control Module
• Use an OBD-II scanner to confirm the code.
• Inspect the ECT sensor and its wiring for damage.
• Check the sensor's resistance with a multimeter.
• Replace the ECT sensor if faulty.
• Repair or replace damaged wiring.
• Ensure all electrical connections are secure.
• OBD-II scanner
• Multimeter
• Socket set
$50 - $200
Moderate
• Toyota Camry
• Honda Accord
• Ford F-150
• Regularly check and maintain coolant levels.
• Inspect wiring and connections periodically.
• Replace sensors as part of routine maintenance.
Sensor Issue
• Do not ignore the Check Engine Light.
• Have the vehicle inspected by a professional if unsure.
• Monitor engine temperature gauge for abnormalities.
Check with your vehicle manufacturer for warranty coverage on sensors.
This code has been common in vehicles with aging sensors or wiring issues.
Moderate – Should be addressed soon to prevent potential engine damage.
Driving with an unresolved engine temperature sensor issue may lead to engine overheating or other performance problems.
• Engine at operating temperature
• Stable electrical system voltage
The ECT sensor is typically located near the thermostat housing or on the engine block.
Q: Can I drive with a P0117 code?
A: It's not recommended to drive for long periods with this code, as it can lead to engine performance issues.
Q: How do I reset the Check Engine Light after fixing the issue?
A: You can use an OBD-II scanner to clear the code, or disconnect the battery for a few minutes.
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Universal · Digital multimeter
A solid entry-level multimeter for voltage, continuity, resistance, and basic electrical troubleshooting.
Helpful for checking voltage drops, grounds, and basic circuit health when modules are not communicating.
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Universal · Wire connectors and repair kit
Useful when diagnosis points toward damaged wiring, corroded terminals, or connector repairs.
Useful if diagnosis points toward damaged connectors, wiring, or terminal repairs.
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Fitment Required · Vehicle-fitment part
Relevant when coolant-temperature and warm-up faults indicate a thermostat-related issue.
Coolant-temperature and warm-up faults often lead to thermostat testing and replacement.
Thermostats are vehicle-specific and should be matched by engine and housing style.
View options on AmazonThese parts may be related to this fault category, but a code by itself does not confirm exact fitment or guarantee that replacing a part will solve the problem.