P0116: Engine Coolant Temperature Sensor 1 Circuit Range/Performance
Key takeaways
- P0116 means the coolant temperature sensor's signal is in range, but it doesn't agree with the other temperature sensors or doesn't change the way a warming engine should.
- It's usually safe to drive; a temperature gauge climbing toward hot, steam or a sweet smell means it's a real overheat and you should stop.
- The usual answers are a sensor reading off, a thermostat stuck open, low coolant, or engine software; a block heater can also set it on some cars.
- A coolant temperature sensor costs $80–$250 and a thermostat $150–$450 at a US independent shop, so check for a software update first.
- Most of the 151 manufacturer bulletins naming P0116 are engine computer reprograms, led by Chrysler, Dodge, Jeep and Ram, with Nissan, GM and Subaru updates too.
What P0116 means
Your engine computer is getting a coolant temperature reading that looks electrically fine but doesn’t make sense. Scanners call it “Engine Coolant Temperature Sensor 1 Circuit Range/Performance.” The coolant temperature sensor is a thermistor, and the computer checks it for plausibility. After the car has sat for hours, coolant and intake air should be close to the same temperature. After a cold start, the coolant reading should rise at a believable rate. And it shouldn’t jump or stay frozen at one value. When the reading fails one of those checks, P0116 sets. Unlike P0117 and P0118, the wiring usually isn’t shorted or open; the reading is simply wrong, or the engine really is warming oddly.
Is it safe to drive?
Yes, usually, while you get it diagnosed. Most cars drive normally with P0116. You might notice weak heat, worse fuel economy or a cooling fan that runs more than usual.
What changes the answer: real overheating signs, such as a gauge climbing toward hot, steam, coolant boiling over, a sweet smell, or the heater suddenly blowing cold. Then it isn’t a sensor problem. Pull over, shut the engine off, let it cool and read car overheating.
Causes, ranked
| Cause | How you confirm it | Typical cost (US independent shop, 2026) |
|---|---|---|
| Engine software (many makes) | Dealer finds a bulletin for your model and engine | $100–$200, often $0 under warranty |
| Coolant temperature sensor reading off | Scanner reading differs from an infrared thermometer at the sensor, or from air temperature after an overnight sit | $80–$250 |
| Thermostat stuck open | Engine slow to warm, gauge low on the highway, weak heat, often with P0128 | $150–$450 |
| Low coolant or air pocket around the sensor | Reservoir below the cold mark; reading jumps around | $0 to top up; $100–$300 for a leaking hose |
| Block heater use (some makes) | Code only sets on cold mornings after the heater was plugged in | $100–$200 software update, often $0 |
| Connector or wiring with high resistance | Reading shifts when the plug is wiggled; corrosion on the pins | $100–$250 |
What to check first
- Check the coolant level with the engine cold. Low coolant can leave the sensor in an air pocket and hides a leak you need to find.
- Ask about software. On many cars the fix is a reprogram, and a dealer can check in minutes.
- Compare temperatures on a cold start. After an overnight sit, coolant and intake air temperature in live data should be within a few degrees. A big gap points to the sensor.
- Watch the warm-up. A reading that climbs steadily and then levels off is normal; one that stalls well below normal operating temperature points to the thermostat.
- Inspect the connector for coolant intrusion or green corrosion.
- Replace parts last, once the software and coolant check out.
The bulletins show a clear pattern: most are engine computer reprograms. Chrysler, Dodge, Jeep and Ram account for 96 of the 151, mostly 2012–2016 Dart, 200, Cherokee, Journey and Ram updates. Nissan reprograms the engine computer for P0116 on 2013–2016 Altimas with the 2.5L, 2013–2015 Pathfinders and Versas, and the 2016 Maxima. GM reprograms the 2024 Buick Envista and Chevrolet Trax, and Mazda and Subaru have updates for the code setting after block heater use. Ford’s 2.7L and 3.0L EcoBoost bulletins point instead to the sensor connector and wiring.
What it costs
The cheap outcome is a software update, $100–$200 or free under warranty, or a coolant top-up. The common outcome is a coolant temperature sensor at $80–$250. The expensive outcome is a thermostat at $150–$450; buried thermostats on some engines cost more. A $100–$180 diagnosis that compares the readings first keeps you from buying a sensor when the thermostat or software is the problem.
Related codes
P0116 often appears with P0128 (engine slow to reach temperature) and P0125 when a thermostat is stuck open. P0117, P0118 and P0119 are the low, high and intermittent codes for the same sensor. If the car’s heat is weak too, see car heater not working.
What owners report to NHTSA
4 complaints filed with NHTSA mention P0116, 3 of them since 2015, across 4 different models. The component owners most often filed it under: engine.
Manufacturer service bulletins that name P0116
151 technical service bulletins and manufacturer communications filed with NHTSA mention P0116, from 16 makes. A bulletin means the manufacturer has documented a known cause or a fix procedure for that model. Examples:
- MACK MACK, bulletin 10208454: Mack DTC P0116 Engine Coolant Temperature Circuit Range/Performance In Tech Tool
- BUICK ENVISTA (2024), bulletin 10252991: This service bulletin advises the tech to re-program the ECM to correct a customer concern of the MIL Illuminated w/DTCs P0324 and/or P0116 Set.
- CHEVROLET TRAX (2024), bulletin 10252991: This service bulletin advises the tech to re-program the ECM to correct a customer concern of the MIL Illuminated w/DTCs P0324 and/or P0116 Set.
- VOLKSWAGEN ATLAS (2020, 2021, 2022, 2018), bulletin 10218956: Customer states rattle noise from the underbody heat shields Customer states MIL-on, fault P0442 and/or P0456 stored in ECM memory Customer states rattle noise under vehicle Customer states MIL-on, fault P0463 stored in …
- VOLKSWAGEN ATLAS CROSS SPORT (2020, 2021, 2022), bulletin 10218612: Customer states rattle noise from the underbody heat shields Customer states brake noise, dust and uneven pad wear Customer states MIL-on, fault P0442 and/or P0456 stored in ECM memory Customer states rattle noise under …
- FORD EXPLORER (2020), bulletin 10177711: Some 2020 Explorer/Aviator vehicles equipped with a 3.0L EcoBoost engine may exhibit an illuminated malfunction indicator lamp (MIL) and/or Engine Coolant Over Temperature warning with diagnostic trouble codes (DTCs) P01…
Sources: NHTSA Office of Defects Investigation complaint database and manufacturer communications file, snapshots September 2026. A complaint or bulletin that mentions a code is a report about that vehicle, not a statement that the code has one cause.
Frequently asked questions
Is my engine overheating if I have P0116?
Usually not. P0116 means the reading doesn't make sense, not that it's high. Check the coolant level when cold and watch the gauge; if it sits in the normal range and there's no steam or sweet smell, the engine isn't overheating.
Can a bad thermostat cause P0116?
Yes. The computer expects coolant to warm at a certain rate after a cold start. A thermostat stuck open keeps the engine cool, so the reading looks wrong. You'll often see P0128 with it, weak cabin heat and a gauge that sits low on the highway.
Why did P0116 set after I used my block heater?
Because the computer compares coolant and air temperature after the car sits. A block heater warms the coolant but not the air, so the two don't match. Mazda and Subaru have bulletins for exactly this, and the fix is a software update.
Should I replace the coolant temperature sensor for P0116?
Not first. Check for a software update, check the coolant level and compare the sensor reading with a thermometer. Many P0116 bulletins are reprograms, and a stuck thermostat can set the code with a good sensor.