P0098
UniversalIntake Air Temperature Sensor 2 Circuit High Input
Medium SeverityThe Intake Air Temperature Sensor 2 circuit is reporting an abnormally high voltage signal to the engine's computer, suggesting that the air entering the engine is extremely cold or that the sensor itself is faulty. This incorrect reading can cause the engine to miscalculate the ideal fuel mixture, leading to issues like decreased fuel efficiency, erratic idle, or a noticeable reduction in engine performance.
⚠️ Before You Begin (Safety First)
Always ensure the vehicle is safely parked and turned off before performing any inspections or repairs. To prevent electrical shocks or damage to the vehicle's systems, disconnect the battery's negative terminal before working with electrical components. Allow engine components to cool down before touching them.
Common Symptoms
- Check Engine Light illuminated
- Decreased fuel economy
- Rough idling
- Reduced engine power
- Engine running rich (excess fuel) or lean (insufficient fuel)
- Poor cold starting performance
Common Causes
- Faulty Intake Air Temperature Sensor 2
- Corroded or loose electrical connection at the sensor
- Damaged or frayed wiring in the IAT Sensor 2 circuit
- Short to voltage in the sensor circuit
- Less commonly, a fault within the Engine Control Module (ECM)
Frequently reported on: General/Universal (often found on turbocharged or supercharged engines with multiple IATs), Ford F-150 (2011-2014), Chevrolet Silverado (2010-2013), Ram 1500 (2009-2012), BMW 3 Series (2007-2011)
Diagnostic Steps
- Connect an OBD-II scanner to confirm the P0098 code and check for any other related codes.
- Visually inspect the Intake Air Temperature Sensor 2 and its wiring harness for any signs of damage, corrosion, or loose connections. Ensure the connector is securely seated.
- Disconnect the sensor and use a multimeter to check for proper voltage (typically 5V reference) and ground at the sensor connector. Also, check for continuity in the sensor's signal wire back to the ECM.
- Test the resistance of the IAT Sensor 2 itself using a multimeter. Compare the reading to the manufacturer's specifications for various temperatures to confirm it's operating within range. An open circuit or extremely high resistance often indicates a faulty sensor.
- If the sensor is found to be faulty, replace it with a new OEM-quality part. Ensure the new sensor is properly installed and the electrical connector is secure.
- Clear the P0098 code from the ECM using the OBD-II scanner and test drive the vehicle to ensure the code does not return.
👨🔧 When to Call a Professional
If after replacing the Intake Air Temperature Sensor 2 and inspecting its wiring, the P0098 code persists, or if you experience other complex drivability issues, it's time to consult a certified mechanic. There might be a more intricate wiring harness issue or even an Engine Control Module (ECM) problem that requires professional diagnostic tools.
Commonly Asked Questions
What does the P0098 code specifically indicate?
The P0098 code indicates that the Engine Control Module (ECM) is receiving an excessively high voltage signal from the Intake Air Temperature Sensor 2 circuit. This usually means the sensor is reporting an implausibly cold air temperature, or there's an electrical fault causing the high voltage.
Is it safe to drive my car with a P0098 code?
While the vehicle may still be drivable, it's not recommended for extended periods. The incorrect air temperature readings can lead to suboptimal fuel mixtures, potentially causing reduced fuel economy, decreased engine performance, and increased emissions.
Where is the Intake Air Temperature Sensor 2 typically located?
The exact location varies by vehicle. Often, if there are two IAT sensors, Sensor 1 is before the turbo/supercharger or throttle body, and Sensor 2 is after, typically in the intake manifold or charge pipe, closer to the engine. Consult your vehicle's service manual for the precise location.
Can I replace the Intake Air Temperature Sensor 2 myself?
Yes, replacing an IAT Sensor 2 is generally an easy DIY task that requires basic hand tools. The main steps involve locating the sensor, disconnecting the electrical connector, unscrewing or uncliping the old sensor, and installing the new one.
What tools do I need to diagnose and fix P0098?
You'll need an OBD-II scanner to read and clear codes, a multimeter for testing voltage and resistance, and basic hand tools (wrenches or sockets) to remove and replace the sensor.