Sonnax 6T70 6L80 6L90 6L45 Transmission Pressure Switch Rebuild Master Pack Listed GM 6-speed transmissions often set various trouble codes related to failures of fluid pressure switches that are internal to the transmission electro-hydraulic control module (TEHCM). These codes may be accompanied by TCC apply problems or shift irregularities such as slipping, flares, harsh application, and bind-ups. As time goes by, the laminated portions of the pressure switches can breach, preventing normal switch operation. If more than one switch breaks down, failsafe mode can be triggered. Since switches cannot be obtained through OE channels, replacement of the TEHCM was the only previous remedy available. It is no longer necessary to replace the expensive TEHCM assembly to rectify this concern. Installing Sonnax pressure switch rebuild master pack 124740-28K restores normal switch operation, eliminating codes and providing renewed shift performance in all ranges. Allows Salvage of expensive TECHM Installation tools included in kit Note: Before Installing kit, test switches to verify proper electrical operation. Kit repairs laminate disc and seal failures only; it will not rectify electrical breakdown. See Instructions for details. Contents: Laminate Discs (40) Seals (40) Seal Installer Piston Seal Plunger Laminate Installation Tool