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P0099 Intake air temperature sensor: signal drops out at times (sensor 2, bank 1)

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P0099 means: Intake air temperature sensor: signal drops out at times (sensor 2, bank 1). A temperature sensor tells the computer the temperature of the air, coolant, fuel or oil. Drive gently and have the car checked soon. The most common repair costs about €45–90 in Estonia, depending on make and model.

Is it safe to drive?Get it checked soonDrive gently and have the car checked soon.
Wiring or connector repair€45–90parts and labour in Estonia, depending on make and model

What it means

A temperature sensor tells the computer the temperature of the air, coolant, fuel or oil. With a wrong reading the computer gets the mixture and the fan wrong. The signal drops out now and then. The most common cause is a loose connector or a chafed wire. Sensor 2 or 3 sits after the catalytic converter.

What you may notice

  • Engine light on
  • Hard cold starts
  • The fan may run all the time
  • Higher fuel consumption

What could be wrong

  1. 1Connector loose, damp or corroded · Wiring or connector repair €45–90
  2. 2Wire broken or chafed · Wiring or connector repair €45–90
  3. 3Faulty sensor · Sensor replacement €80–160
  4. 4Engine computer fault (rare) · Control unit check and software €150–300

Repair difficulty: Easy

What you can check yourself

First look at the connector and wiring: anything loose, melted or green with corrosion? Check the sensor connector and make sure it is clipped in. On a cold engine, compare the reading with the outside temperature. You can do the simpler checks yourself.

How we fix it

  1. We read the fault data on the diagnostic tool and check whether the fault is constant
  2. We measure the circuit's supply, ground and signal
  3. We repair the wire or replace the connector
  4. If the wiring is fine, we replace the sensor

Standard SAE description: Intake Air Temperature Sensor 2 Circuit Intermittent/Erratic Bank 1

This code usually comes with: Check engine lightSee what the light means →

Want a definite answer?

Bring the car to our workshop in Estonia for diagnostics. We read the fault codes, test the sensors and tell you what is wrong. Repair price depends on the work involved, generally €45 per hour.

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Questions

What does fault code P0099 mean?

Intake air temperature sensor: signal drops out at times (sensor 2, bank 1). A temperature sensor tells the computer the temperature of the air, coolant, fuel or oil. With a wrong reading the computer gets the mixture and the fan wrong. The signal drops out now and then. The most common cause is a loose connector or a chafed wire. Sensor 2 or 3 sits after the catalytic converter.

Can I drive with code P0099?

Drive gently and have the car checked soon.

How much does it cost to fix P0099?

It depends on the cause: wiring or connector repair €45–90; sensor replacement €80–160. Prices include labour at €45/h, depending on make and model.

How is P0099 fixed?

We read the fault data on the diagnostic tool and check whether the fault is constant. We measure the circuit's supply, ground and signal. We repair the wire or replace the connector. If the wiring is fine, we replace the sensor.

Related codes

P0098Intake air temperature sensor: signal or voltage too high (sensor 2, bank 1)P0097Intake air temperature sensor: signal or voltage too low (sensor 2, bank 1)P0223Second throttle position sensor signal too highP0297Overspeed: too high (vehicle speed)P0317Traction control signal: not detectedP0070Outside air temperature sensor: circuit fault

Based on AI combined with our hands-on workshop experience and knowledge. This information is general and prices are approximate (Estonian workshop rates). The same code can mean different things on different cars. Only an inspection of the car gives a definite answer.

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