1-2-3-4 Clutch Releases or 2-6 Clutch Releases
WARNING: This page is about a different car, the 2018 GMC Yukon XL, 2018 GMC Yukon, 2018 Chevrolet Tahoe, 2018 Chevrolet Suburban 3500 HD, and 2018 Chevrolet Suburban. However, it is still accessible from the selected car via links, so may be relevant.
C1234 Pressure Control Solenoid 5
If the transmission was in 4th gear when an electrical condition commands a protection mode, the C1234 pressure control solenoid 5 defaults to the OFF position, allowing PCS 1234 clutch fluid from the 1-2-3-4 clutch, the 1-2-3-4 clutch regulator valve and 1- 2-3-4 clutch boost valve to exhaust.
2-6 CB26 Pressure Control Solenoid 4
If the transmission was in 6th gear when an electrical condition commands a protection mode, the CB26 pressure control solenoid 4 defaults to the OFF position, allowing PCS 26 clutch fluid from the 2-6 clutch regulator valve, and the 2-6 clutch to exhaust.