Circuit/System Description
| Component | Description |
|---|---|
| K71 Transmission Control Module | An electronic control module used to control the transmission. |
| Q77 Transmission Control Solenoid Valve - 1, 2, 3, 4, 5 | Part of the Q8 Control Solenoid Valve Assembly A solenoid valve is an electro-mechanically operated valve. The valve is controlled by a pulse width modulated electric current through the solenoid, used to control hydraulic pressure. |
| Q8 Control Solenoid Valve Assembly | A matrix of PWM solenoids and valves that control what gear the transmission is in. |
The transmission control module controls pressure solenoids pressure by regulating the current flow through the pressure control solenoid valve windings. The transmission control module determines the appropriate pressure for a given load by monitoring the throttle position sensor voltage, the engine speed and other inputs. The transmission control module then varies the duty cycle on the high side of the pressure control solenoid valve to control current flow to the solenoid. The magnetic field produced by the coil moves the solenoids internal valve which varies pressure to the pressure regulator valve. The transmission control module controls the pressure control solenoid valve by applying a varying amount of amperage to the solenoid. Current is controlled from about 20 mA for maximum line pressure to 1200 mA for minimum pressure. The transmission control module monitors the actual current to the solenoid as compared to the requested current.
DTC P0741, P0742
When vehicle operating conditions are appropriate to apply the torque converter clutch, the transmission control module will increase current flow to the torque convertor clutch pressure control solenoid valve. The torque convertor clutch pressure control solenoid valve directs fluid pressure to move the torque converter clutch control valve to the apply position and moves the torque converter regulator valve to the regulating position. The torque converter regulator valve controls torque converter clutch apply fluid pressure proportional to torque converter clutch solenoid pressure. When the torque converter clutch is fully applied the engine is coupled directly to the transmission. Torque converter clutch release is accomplished by the transmission control module decreasing current flow to the torque convertor clutch pressure control solenoid valve. This results in decreasing the apply pressure which allows the torque converter clutch control valve to move to the release position. The transmission control module calculates torque converter slip speed based on engine speed and transmission input shaft speed.
DTC P0796, P0797, P02714, P02715
Current is controlled from about 20 mA for maximum line pressure to 1200 mA for minimum pressure. The transmission control module monitors the actual current to the solenoid as compared to the requested current.