“Several reprogramming procedures must be performed after replacement of some components on the new 8L90 8-speed transmission available on the 2015 Corvette, Silverado, Sierra, Yukon, Yukon XL, and Escalade. These procedures are covered in detail in the appropriate Service Information. In addition, the reprogramming procedures also will be used on other transmission applications in future GM models.
Solenoid Valve Characterization Reprogramming
Characterization reprogramming is a new programming procedure. If characterization is not completed when required, shift quality can be less than optimal and may cause the customer to return with a shift concern.
The solenoids in the 8-speed transmission require unique performance characteristic data in order to function at maximum efficiency. This data is programmed and stored in the vehicle’s Transmission Control Module (TCM). (Fig. 4) When a transmission assembly, TCM, or solenoids are replaced during service, the performance characteristic data for the solenoids must be retrieved from the Techline Information System (TIS) website server (the cloud) and programmed into the TCM…”
Reprogramming Procedures for the 8L90 8-Speed Transmission