TCI 377550 - TCI Shift Boss Transmission Programmer

For performance GM 4L60E, 4L65E, 4L70E, 4L80E and 4L85E applications, the TCI Shift Boss is designed to ensure your desired shift firmness while monitoring important drivetrain functions, including line pressure and temperature. Offers three shift modes: Stock, Stage 1, and Stage 2. The Shift Boss warns you of potential problems (e.g. transmission temperature is too high). Simple to install and use, this programmer can be considered inexpensive insurance to monitor and diagnose transmission problems.