Skip the auto shop - Our mechanics make house calls

P2184 OBD-II Trouble Code: Engine Coolant Temperature Sensor 2 Circuit Low

Check Engine Light

P2184 code definition

P2184 is an OBD-II generic code for the engine control module (ECM) detecting the engine coolant temperature sensor (ECT) #2 is indicating low range and does not correlate with ECT sensor #1.

What causes the P2184 code?

  • The engine control module (ECM) checks the ECT and ambient temperature sensors when the engine is first started cold to see if the sensors correlate with each other and with the ambient air temperature sensor.

  • The ECT sensor is not reading within a specified range and is too low when compared to the other sensors.

  • The ECT sensor is too low and is not correlating to the #1 ECT sensor reading and the ambient temperature sensor.

What are the symptoms of the P2184 code?

  • The Check Engine Light will be illuminated and the code is set in the ECM memory as a fault.

  • The ECM will ignore the ECT #2 sensor and will retest it each time the engine has a cold start to verify the failure is still active or not.

  • The engine should run normally as long as the #1 sensor is not having a problem and correlates to the ambient air temperature sensor.

  • The only symptom will be the Check Engine Light not being on as long as only one sensor is failing.

How does a mechanic diagnose the P2184 code?

  • Scans for codes and documents the code in the ECM and looks at the freeze frame data for failure

  • Scans the engine only after the engine has been sitting for at least 8 hours and the coolant is at ambient temperature

  • Scans the ECM and checks readings from the two ECT sensors and the ambient air temperature sensor to see if the ECT #2 sensor is reading a lower temperature than the other two sensors. All three should be within a few degrees of each other

  • Checks the #2 ECT sensor connector for problems like loose or corroded pins

  • Replaces the #2 ECT sensor if all wiring checks out okay and the Ohm's test shows that it is out of specifications

Common mistakes when diagnosing the P2184 code

  • Clearing ECM memory codes before checking the freeze frame data for the main failure problem, so the failure may be duplicated and repaired

  • Failing to clear the ECM codes after the codes are fixed so the ECM will be able to monitor the system like normal again

  • Failing to identify and repair any connector issues before replacing the ECT sensor

How serious is the P2184 code?

  • Code P2184 is a code indicating the number 2 ECT sensor does not match the #1 sensor, and if this sensor fails, then the engine will have running issues. This will fail the vehicle for emissions testing and cause the engine to run too rich during the failure.

What repairs can fix the P2184 code?

Additional comments for consideration regarding the P2184 code

Code P2184 is for the second ECT sensor. The engine has two sensors to back up each other in case of a failure to keep the engine running smoothly. This is so that one failure does not cause any running issues with the engine except for turning on the Check Engine Light.

Failure to fix the problem will keep the Check Engine Light on, and if another fault happens, you would not be alerted to an issue since the Check Engine Light would already be on. In addition, this failure will cause your vehicle to not pass your emission testing in most states and would need to be repaired before retaking the test.

Need help with a P2184 code?

YourMechanic offers certified mobile mechanics who will come to your home or office to diagnose and repair your vehicle. Get a quote and book an appointment online or speak to a service advisor at 1-800-701-6230.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Skip the repair shop, our top-rated mechanics come to you.

At your home or office

Choose from 600+ repair, maintenance & diagnostic services. Our top-rated mechanics bring all parts & tools to your location.

Fair & transparent pricing

See labor & parts costs upfront, so you can book with confidence.

12-month, 12,000-mile warranty

Our services are backed by a 12-month, 12,000-mile warranty for your peace of mind.

Get A Quote

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Need Help With Your Car?

Our certified mobile mechanics make house calls in over 2,000 U.S. cities. Fast, free online quotes for your car repair.


Post a question and get free advice from our certified mechanics.


More related articles

How to Get a Louisiana Driver's Permit
s licensing program. The first step in this program is to obtain...
Veteran and Military Driver Laws and Benefits in New Mexico
The state of New Mexico offers a number of benefits and perks for those Americans who have either served in an Armed Forces branch...
P0291OBD-II Trouble Code: Cylinder 11 Injector Circuit Low
P0291 code definition When your vehicle’s PCM registers the P0291 code, it means that a voltage reading came from the fuel injector circuit – for cylinder number 11’s fuel injector –...

Related questions

Q: check engine light is on -- ge -ot a diagnotics test from onstar -- test stated emmissions system issue whatdoes this mean

Hello, thanks for writing in about your Chevrolet Malibu. If they did not give you the trouble code that is stored then you are going to need to have the system tested to see if the code can be diagnosed...

Q: The truck cut out suddenly

Code P0722 is an output shaft sensor code for the transmission. While that may be an indication of an issue, it would not cause the truck to just quit. A catastrophic failure of the fuel pump, ignition system, or engine...

Q: Misfires, Rough idle, Engine Check light, and Engine not starting

Hello there, many different faults can cause your 2002 Chevrolet S10 to have starting issues, misfires and lack of power. The first step would be to scan the truck to determine what codes are present, this will determine what route...