Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Circuit/System Description
The charge air cooler (CAC) temperature sensor, intake air temperature (IAT) sensor 1, and IAT sensor 2 are variable resistors. The IAT sensor 1 is part of the Mass Air Flow (MAF/IAT) sensor assembly which is located in the intake air duct after the air cleaner assembly. The IAT sensor 2 is located in the CAC inlet duct. The CAC temperature sensor is located in the CAC outlet duct before the throttle body assembly. The engine control module (ECM) supplies 5 V to the signal circuits, and a ground for each sensor's low reference circuit. The ECM monitors the CAC temperature sensor and the IAT sensor 2 circuits in order to calculate the temperature of the fuel air. The ECM monitors the CAC sensor and IAT sensor 2 signal for excessively high or low voltages, or for a voltage that is not in correlation with the other sensor's start up signal.
The ECM monitors the signals from three sensors to calculate the efficiency of the cooler:
- CAC temperature sensor
- IAT sensor 1
- IAT sensor 2
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.