Intake Air Temperature Sensor 2 Circuit High Bank 1
Code P0098 indicates the PCM detected an abnormally high voltage signal from the Intake Air Temperature (IAT) Sensor #2 circuit. This typically means the sensor is reading cooler air than physically present, or the signal circuit has an electrical fault causing elevated voltage.
What You Might Notice
- Check Engine Light (MIL) illuminated
- Rough idle or hesitation during acceleration
- Poor fuel economy
- Difficulty starting the engine
- Potential limp mode activation
Most Common Causes
- 1
Faulty IAT Sensor #2
The sensor has internally failed or degraded, causing it to output an incorrect high voltage signal to the PCM regardless of actual intake air temperature.
- 2
Open or broken signal wiring
The IAT sensor signal circuit wire is broken, disconnected, or corroded, preventing proper voltage transmission and causing the PCM to read a default high voltage state.
- 3
Short to voltage in signal/reference circuit
The IAT sensor signal or reference wire is shorted to battery voltage or another high-voltage source, forcing the circuit voltage abnormally high.
- 4
Poor connector contact or ground circuit fault
Corrosion, loose pins, or an open ground circuit at the IAT sensor connector prevents proper signal return, creating a high-voltage reading condition.
How to Diagnose It
- 1
Check Faulty IAT Sensor #2 — The sensor has internally failed or degraded, causing it to output an incorrect high voltage signal to the PCM regardless of actual intake air temperature.
- 2
Check Open or broken signal wiring — The IAT sensor signal circuit wire is broken, disconnected, or corroded, preventing proper voltage transmission and causing the PCM to read a default high voltage state.
- 3
Check Short to voltage in signal/reference circuit — The IAT sensor signal or reference wire is shorted to battery voltage or another high-voltage source, forcing the circuit voltage abnormally high.
- 4
Check Poor connector contact or ground circuit fault — Corrosion, loose pins, or an open ground circuit at the IAT sensor connector prevents proper signal return, creating a high-voltage reading condition.
How to Fix It
- 1
Inspect and test IAT Sensor #2
Use a multimeter to measure the sensor's resistance and voltage output. A resistance reading outside manufacturer specs or failure to vary with temperature indicates sensor failure requiring replacement.
- 2
Check IAT sensor wiring and connectors
Inspect the sensor harness for breaks, corrosion, or pinched wires. Check the connector for loose pins, corrosion, or damage. Clean connectors with electrical contact cleaner and reseat firmly.
- 3
Verify ground and signal circuits
Use a multimeter to test continuity of the IAT ground circuit and signal wire. Trace the wiring away from high-voltage components like the alternator and spark plug cables to rule out electromagnetic interference.
- 4
Replace or repair wiring harness
If wiring is damaged, shorted, or routed too close to high-voltage sources, repair or replace the affected section of the harness and reposition away from ignition components.
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