SHOE-TRACK 6Y6395 - Caterpillar

Each speed sensor has two connections to the ECM (+ and -). For all of the speed sensors, connector contact "2" is the signal line and connector contact "1" is the return line. The speed sensors send an AC frequency signal (HZ) that matches the number of gear teeth passing the sensor per second to the ECM. The ECM compares the frequency from the speed sensor (HZ) to the number of pulses per revolution in order to determine the speed of the rotating components. The ECM uses the input from the speed sensors in order to regulate transmission shifts.
Illustration 1 g01727973
There is one harness that allows the engine output speed sensor (1) to be mounted on the engine flywheel housing, one transmission output speed sensor (2) , and one torque converter output speed sensor (3) on a TH48-E70 transmission. A second transmission output speed sensor (4) is provided for customer use. All speed sensors are used to determine if any individual speed sensor has failed.