Circuit/System Description

The engine control module (ECM) monitors the ambient air temperature, and the charge air temperature before and after the charge air cooler to calculate the efficiency of the charge air cooler (CAC). The charge air cooler systems' function is to reduce the temperature of the induction air charge that is heated by the turbocharger to improve the efficiency and performance of the engine.

The charge air cooler inlet temperature sensor, located at the outlet of the turbocharger, the charge air cooler outlet temperature sensor, located near the intake air flow valve are variable resistors. The ECM supplies 5 V to the signal circuit, and a ground for the sensors' low reference circuits.