Skip the auto shop - Our mechanics make house calls
  1. Home
  2. Articles
  3. P0111 OBD-II Trouble Code: IAT sensor circuit range or performance problem

P0111 OBD-II Trouble Code: IAT sensor circuit range or performance problem

check engine light

P0111 code definition

Intake Air Temperature (IAT) sensor circuit range or performance problem

What the P0111 code means

P0111 is the OBD-II generic code that indicates the engine control module (ECM) has recorded the IAT sensor input go out of the sensors range or the sensor performance was not as the ECM expected.

What causes the P0111 code?

  • The IAT sensor range input to the ECM went to -40°F or 240°F indicating a short or open circuit.

  • The IAT sensor input to the ECM is erratic and not giving a steady stable reading.

What are the symptoms of the P0111 code?

  • The ECM will turn on the Check Engine Light and go into a failsafe mode.
  • The engine may have a hard start condition.
  • The engine may also have a reduction in fuel mileage.
  • The exhaust may blow black smoke.

Note: The symptoms are determined by the manufacturer failsafe ECM strategy for the vehicle during a failure and may vary between manufacturers and vehicles.

How does a mechanic diagnose the P0111 code?

  • The mechanic will need to do a visual inspection to determine any electrical connector, wiring, or sensor issues.

  • The technician will scan and document the codes received and view the freeze frame data to see when the code was set.

  • The codes should then be reset to clear the OBD-II fault codes and retest the vehicle to see if the code comes back.

  • The mechanic will observe the sensor’s live data on the scanner for temperature output to be within specifications.

If no problems are noted, then the next step for the technician to do is to perform a manufacturer's specific pinpoint tests for the code and repair as needed.

Common mistakes when diagnosing the P0111 code

  • Not doing a visual inspection first

  • Not following the manufacturer pinpoint test procedure step-by-step and skipping steps

  • Replacing an IAT sensor before tests indicate a problem

  • Before installation of the new IAT sensor, not connecting it and viewing the ECM data to see if the temperature output from the sensor is as expected

How serious is the P0111 code?

  • The P0111 code will cause the engine ECM to go into a failsafe mode.

  • The failsafe mode may cause excessive fuel consumption, carbon fouling of engine components, and various drive complaints, depending on the manufacturer failsafe mode strategy.

  • Driving the vehicle for an extended time with the vehicle in failsafe mode may require additional repairs to remove carbon or repair possible ignition problems.

What repairs can fix the P0111 code?

  • Repairing or replacing the IAT connector
  • Repairing or replacing the wiring as necessary
  • Repositioning the sensor back into the air filter housing or intake air tube
  • Replacing the IAT with a new sensor

Additional comments for consideration regarding the P0111 code

  • The P0111 code is often associated with P0112, P0113, and P0114 codes.

  • Most failures for code P0111 are a harness shorting or a connector corrosion issue.

Need help with a P0111 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

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.


More related articles

Insurance Requirements for Car Registration in Kentucky
The Kentucky Transportation Cabinet requires that all drivers in Kentucky carry liability automotive insurance, or “financial responsibility” in order to operate a vehicle legally and maintain vehicle...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...
Veteran and Military Driver Laws and Benefits in Idaho
The state of Idaho offers a number of benefits and perks for those Americans who have either served in an Armed Forces branch in the...

Related questions

Q: 2000 Audi has 1141 and 1423 codes

For one, Audi dealers are extremely expensive. I had some bad experiences there myself and I would never really recommend someone to go to a dealer. They are going to need a dealer level scan tool. They are going to...

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: The truck is riding hard

When you say the truck is riding hard, I have seen many of the suspension struts binding causing a hard ride. They do not shift to smooth ride and may stay stiff. Replacing the shock/struts fixed the issue with ride....