Circuit/System Description

WARNING: This page is about a different car, the 2018 GMC Yukon XL, 2018 GMC Yukon, 2018 Chevrolet Tahoe, 2018 Chevrolet Suburban 3500 HD, and 2018 Chevrolet Suburban. However, it is still accessible from the selected car via links, so may be relevant.

The automatic transmission input and output speed sensor (ISS and OSS) assembly each are part of a single harness. The ISS is a hall-effect type sensor. The ISS/OSS mounts to the control valve upper body assembly. The ISS sensor end faces the splines on the 1-2-3-4 and 3-5-R clutch housing outside diameter surface. The sensor receives 9 volts on the ISS/OSS supply voltage circuit from the control solenoid valve assembly. As the 1-2-3-4 and 3-5-R clutch housing rotates, the sensor produces a signal frequency based on the splines on the clutch housing outside diameter surface. This signal is transmitted through the ISS signal circuit to the control solenoid valve assembly. The control solenoid valve assembly uses the ISS signal to determine line pressure, transmission shift patterns, torque converter clutch (TCC) slip speed and gear ratio.