Q: How to replace the CHT sensor in Lincoln MKX?
A: The CHT sensor is a crucial component of the Fail Safe Cooling system. It adjusts its voltage output based on temperature changes, with resistance values affecting the voltage signal. If the sensor temperature drops, resistance values increase and voltage rises. When the cylinder head temperature surpasses 265-degrees F, the PCM disables half of the fuel injectors at a time, with the non-fueled cylinders acting as cooling air pumps for the others. If the temperature exceeds 330-degrees F, all fuel injectors are disabled. A problem in the CHT sensor circuit triggers a diagnostic trouble code. For four-cylinder models, disconnect the negative battery terminal cable, remove the air filter outlet duct, disconnect the charge air cooler inlet pipe, pull back the rubber weather cover from the CHT sensor electrical connector, disconnect the connector, and unscrew the CHT sensor from the cylinder head. For V6 2.7L models, remove the two fasteners on the engine cover, lift up at the front, unhook the retainers at the rear, locate the CHT sensor in the driver cylinder head, disconnect the electrical connector, unscrew the CHT sensor, and install a new one. For 3.5L and 3.7L models, disconnect the negative battery terminal cable, remove the lower intake manifold, disconnect the CHT sensor electrical connector, unscrew and remove the CHT sensor, and install a new one.