Intake Air Temperature Sensor 2 Circuit High Input
The engine computer detected that the intake air temperature sensor 2 is sending a voltage signal that's too high, meaning it's reading the air as colder than it actually is. Think of it like a thermometer stuck on an artificially low reading—the engine adjusts fuel mixture incorrectly based on bad information.
The ECM monitors voltage from the IAT sensor 2, which uses a negative temperature coefficient thermistor that changes resistance with air temperature. When voltage exceeds the upper threshold (typically 4.8–5.0V), the ECM interprets this as a sensor circuit fault or sensor malfunction. The sensor should produce a voltage range of 0.5–4.5V under normal operating conditions.
| Parameter | Normal Range | Fault Condition |
|---|---|---|
| IAT Sensor 2 Voltage | 0.5–4.5V (approximately -40°C to +125°C) | >4.8V (open circuit or short to voltage) |
| Signal Response Time | Smooth, gradual voltage changes | Erratic or stuck-high readings |
Code P0098 is a moderate fault. You can generally drive to a workshop, but avoid long trips or high-load driving (motorway, uphill towing) until it is diagnosed. If the code keeps returning after clearing, or if you notice the symptoms listed above worsening, do not delay professional diagnosis. Many moderate codes have multiple possible root causes — a mechanic with live OBD data can identify the exact fault more efficiently than part-by-part trial and error.
Once the fault is repaired, P0098 can be cleared using any OBD-II scanner. Connect the scanner, navigate to "Clear Codes" or "Erase DTCs," and confirm. The check engine light turns off immediately.
The code will return if the root cause was not actually fixed. The ECM re-detects the fault within 1–3 drive cycles and sets the code again.