The IAT sensor circuit is faulty — engine can't correct fuelling for air density.
P0110 — also written PO11O, P 0110, 0110 — is the OBD-II code for intake air temperature (iat) sensor circuit. Same code, same fix: this page covers every spelling of it.
P0110 means the brain of the car has lost touch with the thermometer in the intake. It’s very common on high-mileage Vauxhalls and older Fords where the wiring harness gets brittle.
P0110 is a sensors fault code, typically costing £25–£150 to put right in a UK garage.
What P0110 actually feels like to drive
- The engine light is staring you in the face, but the car drives mostly okay.
- Noticeable drop in MPG—she's drinking like a fish because the ECU thinks it's freezing outside.
- A bit of a 'stumble' or hesitation when you first pull away from the lights.
- Black smoke out the back when you boot it on the motorway slip road.
- Hard starting on humid mornings, even though the battery is fresh.
What causes P0110?
- Failed IAT sensor
- Damaged connector
- Wiring break
UK vehicles that throw P0110 most often
- Vauxhall Astra J 1.7 CDTi (A17DTR) 2009-2014
- Ford Transit 2.2 TDCi (Puma engine) 2006-2014
- BMW 320d (E90/E91) N47 engine 2007-2012
- Vauxhall Insignia 2.0 CDTi (A20DTH) 2008-2015
- Volkswagen Golf Mk5/Mk6 1.9 & 2.0 TDI (BKD/BLS) 2004-2012
How P0110 is fixed
- Replace IAT sensor
- Repair connector or wiring
The P0110 misdiagnosis that wastes money
I see folk firing new MAF sensors at this all day long because they’ve been told the IAT is 'inside the MAF'. While that’s often true on your common-rail diesels, I’ve lost count of the times it’s actually a broken wire in the loom near the plug. On the Vauxhall 1.7 CDTi especially, the wiring harness rubs through or the pins in the connector get 'green crusties' (corrosion). You can fit a £150 Bosch sensor and still have the same code if you haven't checked the 5V reference feed first.
What a UK garage should charge for P0110
For a simple standalone IAT sensor on an older car, you're looking at £25 for the part and 30 mins labour. However, on most modern UK cars, the IAT is part of the Mass Air Flow (MAF) sensor. A quality Bosch or Denso MAF unit will set you back £80-£130 from a factor like Euro Car Parts or GSF. Add £40-£60 for a proper diagnostic plug-in and half an hour's fitting. If you go to a main dealer, expect to pay double that for the exact same branded part in a 'genuine' box.
P0110 repair cost in the UK
Most P0110 repairs land between £25–£150 including parts and labour. The spread is wide because the cheap fix (a sensor, a hose, a leak) and the expensive fix (a major component) throw the same code — which is why a proper diagnosis before parts are bought saves the most money.
Bob's tip on P0110
If your garage says 'it needs a new sensor' without even opening the bonnet, walk away. Insist they do a 'live data' check. On a cold engine that's sat overnight, the Intake Air Temp and the Coolant Temp should be within a couple of degrees of each other. If the IAT is reading -40°C or +150°C while it's a drizzly Tuesday in Perth, it's a circuit fault. Also, check if you've got an aftermarket 'tuning box' or a cheap 'resistor chip' from eBay plugged in—these are notorious for throwing P0110 codes because they trick the IAT signal to dump more fuel.
Can you drive with P0110?
Yes.
Urgency: low.