P2199
Intake Air Temperature Sensor 1/2 Correlation
Fuel & air metering
Generic OBD-II
Low
What it means
P2199 means the two intake-air temperature (IAT) sensors are reporting temperatures that disagree by more than the ECM allows. After the engine has sat and cooled, both should read close to the same value, so a mismatch points to one sensor drifting or a wiring problem. IAT is only a minor fueling input, so the car drives normally — the main effect is slightly less accurate cold-start fueling.
Low
Can I keep driving? Safe to drive — a mismatch between the two intake-air temperature sensors has only a minor effect on cold-start fueling and economy; there is no immediate risk.
Common symptoms
What you'll notice
- Check-engine light on
- Often no noticeable driving symptom
- Slightly rough or richer cold start
- Minor drop in fuel economy or throttle response
Common causes
Most likely first
- One intake-air temperature sensor drifting out of calibration (IAT 1 or IAT 2, the latter often built into the MAF)Likely
- Open, shorted, or high-resistance wiring at one IAT sensorCommon
- Poor electrical connection or corrosion at a sensor connectorCommon
- A genuine temperature difference between sensor locations after a repair or relocationLess often
- Faulty ECM (least likely)Less often
How to diagnose & fix
Work through it in order
- With the engine cold and off overnight, compare both IAT readings on a scan tool — after a cold soak they should read within a few degrees of each other.
- Inspect the wiring and connectors at both sensors for corrosion, damage, or loose pins.
- Measure each sensor's resistance and compare it to the temperature-vs-resistance spec.
- Replace whichever sensor reads out of range (IAT 2 may mean replacing the MAF if it is integrated), then clear and re-test.
FAQ
Quick answers
Is it safe to drive with P2199?+
Yes. Intake-air temperature is a minor fueling input, so the effect is small — mainly slightly off cold-start fueling and economy. Still, repair it to keep the mixture accurate.
Can I just clear P2199?+
It clears, but if one sensor is drifting or a connection is poor the mismatch returns. Identify and replace the out-of-range sensor first.
Related codes
Often seen with P2199
Read & clear P2199 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX