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: For details refer to the owner's manual. - Automatic Transmission
| Circuit | Description |
|---|---|
| Signal | The control module input circuit has an internal resistance connected to 12 V. - K9 Body Control Module |
| Ground | Chassis Ground |
| Component | Description |
|---|---|
| K9 Body Control Module | The control module contains a microprocessor used to process input data to control outputs. |
| K71 Transmission Control Module | 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. |
| S2 Transmission Manual Shift Switch | The switch S2 has an internal resistor ladder network. A specific resistance is generated dependent on the position of the switch. S2 is part of the component: Transmission Control Lever |
The switches are connected in series between the ground and the signal circuit and are inputs to the control module K9. When a switch is pressed, the voltage drop across the switch changes. The driver shift request is sent over serial data to the control module K71. The control module K71 ignores a shift request if the transmission shift lever is not in the manual mode position, or the operating conditions are out of range.