Automatic cars tend to have three special forward gears, which are combined in the following way.
l
s/m
l/m
This is a relatively common mode, and only a very small number of automatic transmissions (at) will currently have models that only retain l/s gear, and most of the rest will be a combination of the two. So what is the use of the s-stop, and can it be directly "broken" during driving? In fact, these two special modes can be switched directly with the d gear, because there is also a TCU control unit "pocket bottom".
This is the shift logic of the automatic transmission, the tcu is the brain of the transmission (mt manual transmission does not have this module); all the actions of the forward gear and reverse gear are judged and operated by the control unit, and only a few special modes need to be manually controlled.
p
n
s/l/m
P-stop is defined as parking gear or parking gear, which is a parking mode that prevents slipping; in addition to the mt-based amt electronically controlled mechanical automatic transmission, the remaining at/dct/cvt have this mechanical structure.
Whether it is a p-stop controlled by a knob, a button or a gear lever, the basis for realizing parking is the ratchet claw; the ratchet meets the power output shaft of the gearbox and rotates, and the parking is naturally stopped, at this time, the ratchet is stuck into the ratchet by mechanical operation or the electronic control operation of the button knob, and the ratchet cannot be operated - the ratchet cannot be rotated, the transmission system is fully stopped, and the wheel cannot be rotated.
Note: P gear should be suspended after the vehicle is parked and pulled up the handbrake, otherwise the p gear is hung first and then the brake is loosened and the handbrake is pulled, and the ratchet ratchets that are only combined but not "unusual" will interact, which will accelerate the metal fatigue of the material. To put it bluntly, it will hurt the gears and pawls, unless the vehicle has an automatic parking system, it is still recommended to hang up the gears in the correct order.
As for the n-stop, I believe that it does not need to be repeated, because it is a neutral gear; when you stop for a short time to wait for traffic, you can use n-stop, but do not hang p-stop on the road with complex traffic flow. Because if the vehicle is rear-ended in p-gear, the ideal result of the ratchet pawl is to separate due to impact, and bad luck may break the pawl or cause the ratchet to break the teeth.
The "r/d" gear also does not need to explain anything, after hanging in, the throttle is manually controlled, and the ecu controls the engine through the throttle signal; the tcu linkage ecu decides whether to lift the gear or reverse, as long as the gear is hung up, it only needs to control the throttle. However, the reverse gear must be switched after the vehicle is parked, otherwise the clutch or torque converter and gears may be damaged.
D gear is a drive driving gear, which is essentially a forward gear marked with numbers; 6mt refers to a manual transmission with six forward gears, and 6at as an automatic transmission with six forward gears. Manual transmission cars need to manually operate the gear lever shift, and the automatic transmission is nothing more than the automatic lifting and lowering of the forward gear controlled by the tcu linkage ecu in d mode - d is the real automatic gear, prnd still needs to be manually switched.
Core question: What does s/l/m mean?
These three forward gears are actually equivalent to "speed limit gears", and what can be achieved through the control of the throttle in d mode is the automatic upshift of the forward gear. But sometimes you only need to increase the throttle to pull up the speed without upshifting, such as climbing when you have to use 1-3 gears to amplify the power, not suitable for 4-6 gears to enlarge the speed; if you automatically upshift in the process of accelerating the breakout, the result is that the speed is difficult to increase, the acceleration is very weak, and then the TCU has to downshift to accelerate.
Climbing with d gear will be carried out in continuous lifting and lowering gears, and vehicle safety cannot be optimally controlled; then at this time, after switching to l(low) low speed gear with the mode, the forward gear can only rise to 3 gears, and when climbing, there is no need to worry about the speed of the car. L-gear can also be used when going down steep slopes, and low-speed gear can achieve effective engine braking (speed limit) when going downhill.
The essence of the s·sport mode is the "downshift overtaking" program, when overtaking, you want to quickly pull up the speed to improve the output horsepower, the most ideal way is to downgrade 1-2 forward gears, such as 6 gears cruise, overtaking down to 4 gears. However, the automatic transmission is not easy to manually operate the forward gear, so the s mode is set.
To put it bluntly, this is a control program, the operation of switching with the gear lever or knob is nothing more than to give the tcu a command, and the control unit will automatically downshift according to the setting program after receiving the instruction. The whole process is carried out in the established procedures and standard safety mode, so there is absolutely no damage to the gearbox; and it does not matter whether to switch from d gear or switch back to D gear, is not this how manual transmissions operate? ——It is nothing more than a lift forward gear, what can it damage?
M·manual mode is actually semi-automatic, after switching to m mode (mostly marked with ± number), whether it is pushing and pulling the gear lever or using the steering wheel paddle operation; these mechanical structures are like "remote control buttons", only through the button to the control unit (tcu) a signal, and then the control unit will determine whether to execute after judging the rationality of the operation.
That is, the tcu still has a protective program, if it continues to upshift during the deceleration to the stop stage, it will not be performed, because such an operation will damage the gearbox; and if you forget to manually downshift during deceleration, the tcu will still automatically downshift to prevent failure. What m gear can do is only manually select after the forward gear, not manually upshift is not upgraded - the function is equal to the [hold] button reserved on the panel of some vehicles, that is, the function of locking or limiting the upshift, assuming that the manual rise to 3rd gear and then deceleration, tcu automatically downshift 1 gear and then accelerate, the highest can only be 3 gears.
m-gear is mainly used for climbing, downhill, overtaking (racing), or traction trailer and heavy load; daily overtaking can be used with s-gear, m/s can be switched at high speed. However, the l gear should not be switched randomly when driving at high speed, otherwise it will be quickly downshifted for engine braking, and the low speed gear is only suitable for l/d or d/l switching at low speed.
This is the function of all modes of the gearbox, as long as the mode is not switched to r or p during the drive; basically all automatic transmissions will return to n gears during driving, and the transmission equipped with electronic gear levers will return to neutral gear even if it is hung p gear, but if the transmission with the mechanical gear lever is hung in low speed, it is really possible to make the ratchet ratchet claw mesh Oh, so the p gear can not be hung randomly.
Edit: Day and auto - AutoMotive Science Island
Days and mcn authorized release
Welcome to forward the message to discuss