• Pressure switch codes
  • Switch codes
  • Pressure control out-of-range codes
  • Slips, flares & bind-ups
  • Failsafe mode
  • Erratic TCC apply
  • Harsh shifts
  • Shift codes


OE pressure switch laminate disc breached, preventing proper switch operation.


Salvage the transmission control unit and restore normal shift operation by installing Sonnax pressure switch rebuild kit.

6L45, 6L50, 6L80, 6L90, 6T70 (Gen. 1), 6T75 (Gen. 1)

Pressure Switch Rebuild Kit
Part No. 124740-30K

View Instructions Find a Distributor

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 kit 124740-30K restores normal switch operation, eliminating codes and providing renewed shift performance in all ranges.

  • Allows salvage of expensive TEHCM

The 6T70 Pressure Switch Rebuild Kit has saved me a TON of money!

J. Yarbrough
Certified Transmissions

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.

  • Laminate Discs (5) 1 Extra
  • Seals (5) 1 Extra
  • 124740 30k