P0114
PowertrainIntake Air Temperature Sensor 1 Circuit Intermittent
The ECU watches the voltage coming back from the intake air temperature sensor and expects it to change smoothly as the incoming air warms up or cools down. With P0114 it's seeing the signal jump around or drop out for a split second instead of moving in a sensible way, so it logs an intermittent fault. For you the driver, it means the engine occasionally gets a wrong reading on how warm the air entering it is, which can throw the fuel mixture off just enough to cause the odd hiccup. Because it's intermittent, it's the kind of fault that comes and goes, which makes it a pain to pin down.
ⓘ Information only. This page provides general educational information about fault code P0114. We do not assess the urgency or safety implications of any specific fault. That requires in-person diagnosis by a qualified mechanic. Full terms.
Recommended next steps
Whether a fault is urgent, drivable, or routine depends entirely on the cause on a specific vehicle, and that can only be determined by a qualified mechanic with diagnostic equipment. If a warning light is illuminated, the most reliable next step is professional diagnosis.
What does P0114 mean?
P0114 is a Powertrain (engine, transmission, fuel system) fault code. It indicates: Intake Air Temperature Sensor 1 Circuit Intermittent.
This is a standardised OBD-II code. The technical definition is the same regardless of the make or model of vehicle, although specific causes and symptoms can vary between vehicles.
Symptoms commonly associated with this code
Symptoms that drivers often report alongside this code. Not all may apply to every case:
- • Engine warning light that sometimes comes on and then clears itself a few days later
- • Brief stumble or flat spot when you first pull away, usually worse on a cold morning
- • Slightly rough idle that settles after the engine warms up
- • Small drop in fuel economy that you'd only spot over a tank or two
- • Occasional awkward starting, more common in damp weather
- • On some cars, a noticeably hesitant throttle response when the fault is active
Possible causes
Causes commonly associated with P0114, listed in approximate order of typical investigation. The actual cause on a specific vehicle can only be confirmed by professional diagnosis.
- 1. Damaged or corroded wiring and connector at the sensor, the usual culprit since the IAT often sits in the intake pipe where it picks up vibration and moisture
- 2. A failing sensor with internal resistance that flickers as it heats and cools, common once a car is past 80,000 miles
- 3. Loose or backed-out connector pins giving an on-off contact, often after someone has been working in the area
- 4. A poor earth or weak reference voltage on the sensor circuit causing the reading to drift
- 5. Oily film or debris on the sensor element, which can affect the reading if it's a combined MAF/IAT setup feeding the same connector
- 6. A wiring chafe rubbing against a bracket or the engine block, only shorting when the engine moves on its mounts
- 7. ECU circuit fault on the input side, rare but it does happen
How mechanics typically diagnose
A typical diagnostic sequence used by mechanics, provided here for educational reference only. Diagnostic work should be performed by a qualified mechanic with the appropriate tools and training.
- 1. Read the freeze frame data alongside the code so you know the engine temperature and conditions when it last logged, that tells you whether it's a cold-start or hot fault
- 2. Unplug the IAT connector and check both halves for green corrosion, spread pins, or moisture, then give the wiring a gentle tug to feel for any movement
- 3. Watch the live IAT reading on a scanner and do a wiggle test on the loom and connector while the engine idles, a sudden jump confirms a wiring or connection fault
- 4. Measure the sensor resistance against the workshop spec at a known temperature, most read a few kilo-ohms cold and drop into the low hundreds when hot
- 5. Check continuity and resistance back to the ECU on both the signal and earth wires, anything stubbornly high points to a corroded or broken conductor
- 6. Clear the code and drive it through a few cold and warm cycles to see if and when it returns
Common questions about P0114
How long should this take to sort at a garage? +
If it turns out to be a dirty or corroded connector, a garage can often have it cleaned, reseated and tested inside an hour. A straight sensor swap is also quick, usually under an hour of labour once the diagnosis is done. The catch is the diagnosis itself. Because the fault is intermittent it can take longer to catch in the act, so don't be surprised if a garage wants the car for half a day to road test it and run a wiggle test rather than just throwing a sensor at it.
Should I buy a cheap IAT sensor or pay for the proper one? +
A mid-range aftermarket IAT sensor from a known brand like Bosch, Hella or Febi is fine for most cars and saves you money over main dealer parts. Expect somewhere around £15 to £40 for a decent one. The very cheapest no-name eBay sensors are a false economy because they can read inaccurately and have you back chasing the same fault. If your car uses a combined MAF and IAT unit, that's a different story and a quality OEM-spec part is the safer bet there.
Can I keep driving with P0114 showing? +
For short journeys, yes, it won't leave you stranded. When the signal drops out the ECU falls back on a default air temperature value, so the engine keeps running, just not quite as cleanly. You'll likely feel the odd stumble and your economy may suffer a little. Driving like that for weeks isn't ideal as a constantly wrong mixture can soot up the engine over time, so get it looked at rather than ignoring it.
Is this going to be a problem at MOT time? +
The code on its own isn't an automatic fail. What the tester cares about is whether the engine warning light is lit when they check it. If the light is on at the time of test the car will fail on that alone, regardless of how minor the fault is. Sort the underlying cause and let it clear through a few drive cycles before you book the MOT, otherwise you're handing them an easy fail.
Information only, not professional advice
The information on this page is provided for general guidance and educational purposes only. It is not a substitute for diagnosis or repair advice from a qualified mechanic. Always verify any fault before paying for repairs. carfaultcodes.co.uk accepts no liability for decisions made based on this information. Full terms →