Intake Air Temperature Sensor
2018 Toyota Camry · 2.5L I4 Hybrid
Sensor Type
thermistor
Waveform Type
dc-variable
Location
Integrated into the Mass Airflow Sensor housing on the intake duct between the air filter box and throttle body
Pins
2-pin connector
Timebase
1s/div for monitoring temperature changes
Voltage Scale
1V/div
Trigger
N/A - DC signal
Wiring
Light Green/Black wire (signal) and Brown wire (sensor ground), part of the MAF sensor 6-pin connector
Expected Voltage Range
At Idle
1.5V to 3.5V
At Higher RPM
1V to 2.5V
Expected Pattern
Steady DC voltage inversely proportional to intake air temperature; cold air (0°C) shows ~4.0V, ambient (20°C) shows ~2.5V, hot engine bay (60°C) shows ~1.0V
Known-Good Waveform
At ambient temperature (20°C), expect 2.3-2.7V with very stable reading during idle. Under acceleration, voltage may decrease slightly (0.1-0.3V) due to intake heating from turbo bypass or engine heat. Signal should be rock-steady with no noise or fluctuation greater than 0.05V.
Common Failure Patterns
Fixed voltage at 4.8-5.0V regardless of temperature
Cause: Open circuit in IAT sensor element or wiring break
Reading shows -40°C (-40°F) or voltage near 5V constantly
Cause: MAF sensor connector corrosion or water intrusion, common in high-humidity environments
Related DTCs: P0113
IAT reads excessively high (120°C+) with voltage below 0.5V
Cause: Short to ground in wiring or failed thermistor element
Related DTCs: P0112
Diagnostic Tips
The IAT is part of the MAF sensor assembly; replacing IAT requires replacing entire MAF unit. On 2018-2020 models, TSB T-SB-0031-20 addresses false IAT codes caused by software calibration - update ECM software before replacing parts.
Related Diagnostic Trouble Codes
P0110P0111P0112P0113P0114
Always confirm waveform data with your vehicle's OEM service manual before diagnosing.
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