Note: P0127 is actually "Intake Air Temperature Too High," not a throttle position correlation code. If your 2020 Infiniti QX60 is showing P0127, the intake air temperature sensor is reading excessively high temperatures that may affect engine performance.
What P0127 Actually Means
P0127 indicates the Intake Air Temperature (IAT) sensor is reading temperatures above the maximum threshold—typically indicating intake air over 250-300°F. Such extreme temperatures are abnormal and usually indicate sensor failure or specific operating conditions rather than actual intake air temperature.
IAT Sensor Function
The IAT sensor measures incoming air temperature, which the ECU uses to calculate air density and adjust fuel delivery. The sensor is typically located in the intake tract or integrated with the MAF sensor. Normal readings range from ambient temperature up to perhaps 150°F under hot conditions.
Common Causes of P0127
A shorted IAT sensor can output readings indicating extreme high temperatures. Internal sensor failure causes the signal to indicate maximum heat regardless of actual conditions.
Heat soak after hot driving can temporarily raise intake temperatures. If the sensor reads high immediately after parking a hot engine, it may be sensing actual heat soak conditions. This usually resolves after cooling.
Sensor location problems—if an aftermarket intake positions the sensor near heat sources—can cause elevated readings.
Diagnostic Approach
Check IAT readings on a cold start—they should be close to ambient temperature. If reading extremely high (200°F+) on a cold engine, the sensor is likely faulty. Compare to actual temperature using an infrared thermometer. If the sensor reads normally when cold but high during operation, check for heat sources affecting the sensor.