TCM Tuning Kit

The Spelab L5P TCM Tuning Kit offers advanced transmission calibrations specifically for 2017–2026 GM Duramax L5P trucks, engineered to complement upgraded powertrains. This kit functions by licensing your existing factory TCM and uploading pre-built tune files, eliminating the need for any physical component replacements. The kit meticulously recalibrates key transmission functions, including shift timing, shift points, torque converter lockup behavior, and transmission hydraulic line pressure. It features redesigned shift maps to better handle heavy diesel hauling and daily driving, custom shift point calibration that goes beyond OEM limits, and precisely calibrated shift timing for smooth, predictable gear changes. The optimized torque converter lockup logic reduces slippage under load and enhances fuel efficiency, while recalibrated transmission line pressure ensures firmer clutch clamping for reliable torque handling. Compatibility is based on the TCM model: the T87A unit is used for 2017–2019 models (6 and 10-speed transmissions), and the T93 unit is for 2020–2026 diesel applications (10-speed). An OBD2 Flash Tuning Interface is required, and the kit includes 4 OBD2 Tuning Credits. This product is intended for off-road use only and is a final sale, non-refundable item. It is exclusively for L5P diesel applications and does not fit gas engine trucks. The interface requires a Windows-based laptop for operation; Apple products will not work.