Circuit Description

The engine control module (ECM) monitors various sensors to determine engine operating conditions. The ECM controls fuel delivery, spark advance, transaxle operation, and emission control device operation based on the sensor inputs.

The ECM provides a sensor ground to all of the sensors. The ECM applies 5 volts through a pull-up resistor and monitors the voltage present between the sensor and the resistor to determine the status of the engine coolant temperature (ECT) sensor and the intake air temperature (IAT) sensor. The ECM provides the throttle position (TP) sensor and the manifold absolute pressure (MAP) sensor with a 5-volt reference and a sensor ground signal. The ECM monitors the separate feedback signals from these sensors to determine their operating status.