Automatic Transaxle-Transmission External Controls - Transmission Control Switch (TCS)
Automatic Transaxle-Transmission External Controls - Transmission Control Switch (TCS)
Overview
The transaxle selector lever linkage consists of:
- a selector lever cable that connects the transaxle manual control lever to the selector lever assembly.
- a BSIA (Brake Shift Interlock Actuator) that is integral to the selector lever assembly.
- a TCS (Transmission Control Switch) that is integral to the selector lever knob and turns off the operation of 6th gear.
The selector lever assembly:
- locks the transaxle selector lever in the PARK position when the ignition switch is in the LOCK position.
- requires the transaxle selector lever to be in the PARK position to turn the ignition switch to the LOCK position.
System Operation
System Diagram
Range Selection
This transaxle has 5 range positions: P, R, N, D and L.
Selector Lever (vehicles equipped with a TCS (Transmission Control Switch))
Park
In the park position:
- there is no power flow through the transaxle.
- the parking pawl locks the final drive.
- the engine may be started
- the ignition key may be removed.
Reverse
In the REVERSE position:
- the vehicle may be operated in a rearward direction, at a reduced gear ratio.
- engine braking will occur.
Neutral
In the NEUTRAL position:
- there is no power flow through the transaxle.
- the output shaft is not held and is free to turn.
- the engine may be started.
Drive Position With Grade Assist
DRIVE is the normal position for most forward driving.
Drive provides:
- automatic shifts -1st through 6th gears.
- apply and release of the TCC (Torque Converter Clutch).
- maximum fuel economy during normal operation
Manual L Position (vehicles equipped with a TCS (Transmission Control Switch))
In the L position:
- the transaxle provides maximum engine braking.
- the transaxle downshifts to the lowest available gear for the current vehicle speed.
Manual L position allows for 1st gear when the vehicle reaches slower speeds.
Gear Availability
Brake Shift Interlock
Brake Shift Interlock Operation
When the ignition switch is in RUN/START, the solenoid inhibits the selector lever movement (from the PARK position) if the brake pedal is not pressed.
The BSIA (Brake Shift Interlock Actuator) inhibits the selector lever movement from the PARK position by mechanically blocking the detent pawl of the selector lever mechanism. When the brake pedal is applied with the ignition key in the RUN/START position and the transmission in PARK, the BSIA (Brake Shift Interlock Actuator) is energized by the BCM (Body Control Module), this allows the selector lever to be moved out of the PARK position.
Proper Operation Requirements
Three requirements for the selector lever to be moved from the PARK position are:
- Ignition switch in the RUN/START position
- TR (Transmission Range) sensor in the PARK position
- BPP (Brake Pedal Position) switch closed (brakes applied - brake lamps on)
Transmission Control Switch (TCS)
Drive with Grade Assist - TCS (Transmission Control Switch)
Drive with grade assist is activated when the TCS (Transmission Control Switch) is pressed. The TCS (Transmission Control Switch) is located on the selector lever knob. When the TCS (Transmission Control Switch) is pressed, the 6th gear or O/D (Overdrive) upshift is prevented or the transaxle shifts down to 5th gear. The TCS (Transmission Control Switch) is meant to be used when driving conditions cause excessive shifting from 6th to other gears such as hilly terrain, mountainous areas or when engine braking is required.
Grade Assist
- Improves vehicle handling in hilly terrain or mountainous areas by providing engine braking and extending lower gear operation on uphill climbs.
- Additional engine braking is provided through the automatic transaxle shift strategy which reacts to vehicle inputs (vehicle acceleration, accelerator pedal, brake pedal and vehicle speed).
- The transaxle will select gears that will provide the engine braking desired, based on the vehicle inputs, this will increase engine rpm during engine braking.
It is recommended to return to DRIVE mode on flat terrain to provide the best fuel economy and transaxle function. The transaxle returns to O/D (Overdrive) when the TCS (Transmission Control Switch) is pressed again or anytime the key is turned OFF.
Component Description
Brake Shift Interlock Actuator
The brake shift interlock system consists of:
- BSIA (Brake Shift Interlock Actuator) that is integral to the selector lever assembly.
- ignition switch.
- BPP (Brake Pedal Position) switch.
- BCM (Body Control Module).
Selector Lever Cable
The selector lever cable consists of:
- a cable that connects the transaxle manual control lever to the selector lever assembly.
- a cable grommet that is fastened to the floor pan.
- adjuster locking tab at the transaxle manual control lever.
Selector Lever
The selector lever consists of:
- Selector lever knob
- BSIA (Brake Shift Interlock Actuator) that is integral to the selector lever assembly.
- TCS (Transmission Control Switch) that is integral to the selector lever knob.
Transmission Control Switch (TCS)
The TCS (Transmission Control Switch) is a momentary contact switch integral to the selector lever knob.