Circuit/System Description

WARNING: This page is about a different car, the 2023 GMC Sierra 3500 HD and 2023 GMC Sierra 2500 HD. However, it is still accessible from the selected car via links, so may be relevant.

For an overview of the component/system, refer to: Electronic Component Description

Circuit	Description
Control - Terminal 11	The output circuit is switched to 12 V to activate the component.
Control - Terminal 24, 25	The output circuit is switched to ground to activate the component. The output is PWM controlled.

Component	Description
K71 Transmission Control Module	The control module contains a microprocessor used to process input data to control outputs.The control module contains a microprocessor used to process input data to control outputs.The control module receives information from a variety of sensors, switches and serial data information from other control modules. This information is used to control a combination of solenoid valves to obtain the correct line pressure, gear ratio and torque converter clutch operation.
Q77G Transmission Control Solenoid Valve 7	The solenoid actuator varies the force depending on the current applied to the solenoid coil. The solenoid actuator applies maximum force with minimum current applied to the solenoid coil. The solenoid actuator applies minimum force with maximum current applied to the solenoid coil.
Q77H Transmission Control Solenoid Valve 8	A linear solenoid actuator is an electro-mechanical device that converts electrical power into a mechanical pushing or pulling force or motion. The solenoid actuator varies the force depending on the current applied to the solenoid coil. The solenoid actuator applies minimum force with minimum current applied to the solenoid coil. The solenoid actuator applies maximum force with maximum current applied to the solenoid coil.