P0098 Code – Intake Air Temperature Sensor 2 Circuit High

The P0098 OBD2 trouble code indicates that the Engine Control Unit (ECU) has detected a high voltage signal in the Intake Air Temperature Sensor 2 circuit.

The Intake Air Temperature (IAT) sensor measures the temperature of the air entering the engine. The ECU uses this information to adjust several engine parameters, including:

• fuel injection timing

• air-fuel mixture

• ignition timing

• turbocharger boost pressure

When the ECU receives a higher than expected voltage signal, it interprets this as extremely low air temperature. If the signal remains outside the normal range, the ECU will trigger the P0098 diagnostic trouble code and activate the Check Engine Light.

Incorrect intake air temperature data can affect overall engine performance and efficiency.

Symptoms of Code P0098

Drivers may notice several symptoms when the P0098 code is present:

• Check Engine Light illuminated

• Poor fuel economy

• Rough idle

• Reduced engine performance

• Engine hesitation during acceleration

• Hard starting in cold weather

In turbocharged engines, incorrect intake air temperature readings can also cause improper boost pressure control.

Common Causes of P0098

Typical causes of the P0098 trouble code include:

• Faulty Intake Air Temperature Sensor 2

• Open circuit in the sensor wiring

• Damaged wiring harness

• Loose or corroded electrical connectors

• Faulty Mass Air Flow (MAF) sensor

• ECU circuit fault (rare)

In many vehicles, the IAT sensor is integrated with the MAF sensor, which means a faulty MAF sensor may also trigger this code.

How Serious Is Code P0098

The P0098 code is considered a moderate severity problem.

The vehicle will usually remain drivable, but incorrect air temperature readings may cause:

• inefficient combustion

• increased fuel consumption

• reduced engine performance

• higher emissions

Fixing the issue promptly helps maintain proper engine efficiency.

How to Diagnose Code P0098

A technician will usually follow these steps:

1. Scan the vehicle using an OBD2 scanner

2. Check stored and pending trouble codes

3. Review live intake air temperature data

4. Compare sensor readings with ambient temperature

5. Inspect wiring and connectors

6. Test the sensor resistance using a multimeter

7. Check the MAF sensor if the IAT sensor is integrated

If the scanner shows extremely low temperature values, the sensor circuit may have a voltage problem.

How to Fix Code P0098

Possible repair solutions include:

• replacing the Intake Air Temperature Sensor

• repairing damaged wiring

• cleaning electrical connectors

• replacing the MAF sensor

• clearing the fault code after repair

In most vehicles, replacing the faulty sensor resolves the issue quickly.

Vehicles Commonly Affected by P0098

The P0098 trouble code may appear in many modern vehicles equipped with advanced engine management systems, including:

• Ford

• Volkswagen

• BMW

• Mercedes-Benz

• Toyota

• Hyundai

• Kia

• Audi

Vehicles with turbocharged engines rely heavily on accurate intake air temperature readings.

FAQ – P0098 Code

Can I drive with code P0098?

Yes, but engine efficiency and performance may be reduced until the issue is repaired.

What does “circuit high” mean?

“Circuit high” means the ECU receives higher voltage than expected from the sensor circuit.

Can a bad MAF sensor cause P0098?

Yes. In many vehicles the IAT sensor is built into the MAF sensor, so a faulty MAF sensor can trigger this code.

Can cold weather cause the P0098 code?

Cold weather itself does not cause the code, but a faulty sensor may report unrealistic temperature values during cold starts.

Is the intake air temperature sensor easy to replace?

Yes. In most vehicles the sensor is easy to access and relatively inexpensive to replace.

Where is the intake air temperature sensor located?

It is usually located:

• inside the air intake pipe

• integrated with the MAF sensor

• near the throttle body

• after the intercooler in turbo engines

Can a wiring problem trigger P0098?

Yes. An open circuit or damaged wiring can cause the ECU to read incorrect voltage signals.

How can I test an intake air temperature sensor?

You can measure its resistance with a multimeter and compare the values with manufacturer specifications.

What happens if I ignore code P0098?

Ignoring the code may lead to poor fuel economy, reduced engine performance, and increased emissions.

Can clearing the code fix the problem?

Clearing the code will remove the warning temporarily, but the issue will return if the underlying problem is not repaired.