|
|
TCM FUNCTION The function of the TCM is to: I Receive input signals sent from various switches and sensors. I Determine required line pressure, shifting point, lock-up operation, and engine brake operation. I Send required output signals to the respective solenoids. INPUT/OUTPUT SIGNAL OF TCM Sensors and solenoid valves Function Input Park/neutral position switch Detects select lever position and sends a signal to TCM. Throttle (accelerator) position sensor Detects throttle valve position and sends a signal to TCM. Closed throttle position switch Detects throttle valve’s fully-closed position and sends a signal to TCM. Wide open throttle position switch Detects a throttle valve position of greater than 1/2 of full throttle and sends a Engine speed signal From ECM. A/T fluid temperature sensor Detects transmission fluid temperature and sends a signal to TCM. Revolution sensor Detects output shaft rpm and sends a signal to TCM. Vehicle speed sensor Used as an auxiliary vehicle speed sensor. Sends a signal when revolution sen- Overdrive control switch Sends a signal, which prohibits a shift to “D 4 ” (overdrive) position, to the TCM. Output Shift solenoid valve A/B Selects shifting point suited to driving conditions in relation to a signal sent from Line pressure solenoid valve Regulates (or decreases) line pressure suited to driving conditions in relation to Torque converter clutch solenoid valve Regulates (or decreases) lock-up pressure suited to driving conditions in relation Overrun clutch solenoid valve Controls an “engine brake” effect suited to driving conditions in relation to a sig- O/D OFF indicator lamp Shows TCM malfunctions, when A/T control components malfunction. OVERALL SYSTEM Control System (Cont’d) AT-13 |