Question

What is code P0117?

P0117 engine code is defined as “Engine Coolant Temperature (ECT) Sensor 1 Circuit Low,” meaning your car’s powertrain control module (PCM) sensed a low voltage input from the engine coolant temperature (ECT) sensor 1 circuit, signifying a possible problem with the ECT sensor or its wiring.

The ECT sensor checks the differences in the engine’s coolant temperature. The sensor then sends the information gathered to the powertrain control module (PCM), which makes use of the data to control the air-to-fuel ratio, ignition spark timing, cooling fan operation, and other powertrain-related outputs.

When the PCM senses a signal voltage less than the sensor’s standard operating temperature, code P0117 is registered. The low signal that the PCM senses from the ECT sensor can signify that the engine coolant is extremely hot.

What are the symptoms of the P0117 code?

These are some common symptoms you can observe in your car when the PCM logs this error code:

• The check engine light illuminates
• Engine overheats
• Decreased fuel economy
• The engine runs rough or has a hard start
• Issues with drivability
• The engine may not idle
• The engine may start and then die
• Black smoke from the tailpipe

What can cause a P0117 code?

These are some reasons why the engine code shows up in your car:

• Faulty engine coolant temp sensor
• Corroded or defective engine coolant temperature wiring or connection
• Issues with the cooling system, causing the engine to overheat
• A faulty PCM
• Air pocket in the coolant system
• The ECT wiring or sensor is shorted
• Damaged wiring harness
• Loose terminals at PCM or ECT

How to fix the P0117 code​

Follow these steps to repair engine code P0117:

• Reset the error code and do a test drive
• Repair or change the Engine Coolant Temperature (ECT) sensor if required
• Repair or replace the wiring if needed
• Change the ECT with a new sensor

How much does it cost to fix the P0117 code?

It can cost you anywhere between $100 and $400 to repair this engine code. The ECT Sensor replacement can cost from $5 to $250, but it can vary depending on your car model. The labor cost will be between $100 and $200.

Is it safe to drive with a P0117 code?

Though technically you can drive with this error code, we don’t recommend it. If you ignore the issue and drive, it could eventually lead to substantial engine damage. You must try to address the issue as quickly as possible.

Can a bad thermostat cause a P0117 code?

Yes, a bad thermostat triggers this error code. A defective thermostat causes engine overheating, which leads to the malfunctioning of the coolant temperature sensor.