Circuit/System Description

The Transmission Internal Mode Switch contains 9 separate switches in one assembly. The other 4 electronic switches are called the transmission range switches and are used to indicate the gear position the vehicle operator has selected. The Transmission Internal Mode Switch is mounted on the interior left side of the transmission case. The internal mode switch assembly is a dual sliding Hall Effect switch. The nine outputs from the switch indicate which position is selected by the transmission manual shaft. Four outputs (A, B, C, P), are range selection inputs to the transmission control module (TCM). Five outputs (R1, R2, D1, D2 and S) are direction selection inputs to the Hybrid/EV Powertrain Control Module 1, through the transmission X175 connector. The input voltage at the modules is high when the switch is open and low when the switch is closed to ground. The state of each input is displayed on the scan tool as Internal Mode Switch Range and Internal Mode Switch Direction. The Internal Mode Switch Range input parameters represented are transmission range signal A, signal B, signal C and signal P. The Internal Mode Switch Direction input parameters represented are transmission direction signal R1, signal R2, signal D1, signal D2 and signal Start. The Transmission Internal Mode Switch indicates to the TCM which Range position the vehicle operator has selected. The Transmission Internal Mode Switch consists of 9 separate Hall Effect switches. Each Hall Effect switch is supplied a 9 V signal circuit from the TCM. Each signal circuit for each gear selector position will have either a voltage reading of 0.70-0.96 V indicting ON or 1.68-2.38 V indicating OFF. The voltage values on each Transmission Internal Mode Switch circuit will change and are dependent on the position of the gear selector. The state of each Transmission Internal Mode Switch A/B/C/P/S circuit is displayed on the scan tool.