There are different automatic transmissions by design, but as a rule, the basic modes of operation are present in all automatic transmissions. There are hydraulic and hydraulic-electronic types of automatic transmissions. If you do not see additional buttons of switching modes PWR, MANU, SNOW, OD on your automatic transmission, you have a simple automatic transmission with hydraulic control. The automatic transmission may be 4 and 3 speeds (with the mode OverDrive and without it), any 4-speed automatic transmission can be used as 3-speed one, having chosen the mode “OD off” OverDrive is switched off.
Main automatic transmission modes
Modes that no automatic transmission can do without. They may differ in designations from one concern to another, but the essence is the same.
TOYOTA P R N D(OD on) D(OD off) 2 L
HONDA P R N D4 D3 2 L
P
P – Selected when the vehicle is stationary for a long time.
In this position, all controls in the transmission are off and the output shaft is locked.
Do not move the lever to this position until the vehicle has come to a complete stop. Moving the lever to the P position while driving will damage the transmission!
This is commonly referred to as “parking” in automotive circles. This mode should be treated very carefully. Just make it a rule.
If you stop on a steep rise or downhill, it is necessary to use a “handbrake” to reduce the load on elements of a parking mechanism. Apply the handbrake before parking in P, and take it off after changing from P to another mode.
Switching from “parking” mode is possible only with the pressed button on the shift knob (we will call it to lock) and a depressing brake pedal.
R
R – Reverse. You can only move the range lever to this position when the vehicle is stationary.
Moving the lever to this position while driving forward can cause damage to the transmission and other transmission components!
The automatic transmission may also be put into this mode only with the locking device pressed and the brake pedal depressed. After selecting this mode, you may not start moving immediately, but after feeling a jolt of transmission engagement it usually occurs within 1 second.
N
N – Corresponds to neutral. All controls in the transmission are off, which ensures that there is no rigid kinematic connection between its drive and idler shafts. The output shaft locking mechanism is off, i.e. the vehicle can move freely.
It is not recommended to put the range lever in N position during coasting (inertia)
Rest assured, using N during coasting does not save fuel, rather the opposite, Japanese cars can save more fuel if the engine is braked than simply idling in neutral. Many also advise against putting the automatic transmission in this mode when parked at traffic lights. During transferring to N mode, a certain easing of load on elements of transmission is felt but is it normal, because then, inevitably, transferring to another mode will follow, and it will return everything back to the way it was.
Put the car in N mode only when you need to have a working car and move it freely. For example, for repairs and adjustments, measuring the fluid in the automatic transmission, repairing the chassis, etc.
D
D – Basic driving mode. It provides automatic shifting from first to third/fourth gear. In normal driving conditions, it is recommended to use this mode.
When switching to this mode from P or R, it is necessary to press the brake and the lock on the handle, wait for the moment of transmission activation (usually less than 1 second), only then start driving.
In this mode your automatic transmission works like 3 or 4 steps, depending on a condition of button OD-“OverDrive” which is located under a latch on a handle of change of gears, if “OD” is depressed – 4 steps, if “OD” is pressed, then accordingly 3 steps. If there is no “OD” button, the automatic transmission is 3 steps.
2 – Only first and second gears are allowed. It is recommended to use, for example, on winding mountain roads. Shifting to fourth and third gear is forbidden. Engine braking is effective in this range.
Use this mode when driving on a bad road or a road with poor pavement, with frequently alternating short descents and ascents. If you frequently have to brake on a bad road or downhill slope, using Engine Brake mode, as compared to conventional braking, saves fuel.
This mode has restrictions for its use at speeds above 80-100 km/h (depending on the type of automatic transmission)
Also, do not switch to this mode from D mode when the speed exceeds 80-100 km/h (depends on the type of automatic transmission)
L
L – Allowed to drive in first gear only. this mode allows maximum engine braking. It is recommended on steep descents, rises, and off-roads.
This mode is used to overcome steep descents and ascents, and where there is no need to use a gear other than first gear, for example pulling out a stuck car, driving into a garage, overcoming a step or stairs.
This mode has an even more limited speed range than 2 and cannot be engaged without depressing the latch.
Additional automatic transmission modes
Modes add even more flexibility to the use of the automatic transmission, depending on the situation, road surface, and driver’s mood.
Usually, additional modes are realized by the electronics which control the automatic transmission’s hydraulic system. For example, the electronic control system of TOYOTA is called ECT and implements the following automatic transmission modes.
Technological progress does not stand still, and perhaps while we are here to discuss what has already been invented, engineers in Japan have invented a number of interesting modes.
In its mass until 1994, it was rare to see automatic transmissions equipped with electronic control systems. The MARK II, CHASER, CRESTA had only two modes – NORM and PWR, and since 1994 the SNOW mode is available, while on other models since 1994 you can find PWR and MANU.
NORM – The program is configured to ensure that the car drives with minimum fuel consumption. in this case, the upshifts take place approximately when the engine speed reaches average values, which corresponds to the fuel consumption characteristic of the minimum. The movements of the vehicle are smooth and calm.
The normal mode of the automatic transmission, implemented in cars of the middle class until 1994, in general, is the usual mode of automatic transmission in all cars. The maximum fuel economy is achieved in this mode.
PWR – the program is adjusted for maximum engine power, so upshifting takes place in the area of maximum engine revolutions, when the engine develops maximum power. The car in this case accelerates with much more acceleration. If this program is selected, the “ECT PWR” indicator lights up on the instrument cluster The mode may also be referred to as “SHIFT” on Nissan automatics.
The shift to the next speed occurs at higher engine speeds than in normal or NORM mode. This does not mean the engine has to rev up to 6,000 rpm to change to the next gear, if you are not pushing hard on the pedal, the shift will happen sooner without pushing the engine to maximum power, but much later than in Simple mode. This mode is used for a sporty driving style, for various kinds of races and competitions as well as for measuring the actual technical characteristics of the car, comparing them with the catalog, it is possible to judge about the “health” of your car.
When using this mode, the fuel consumption reaches its maximum value.
With PWR in the gearbox, if you select position 2, the car will start in 2nd gear and will never be downshifted to 1st gear.
If the automatic transmission is not equipped with SNOW mode, it can be realized in PWR mode and position 2 on the gear selector
SNOW (snow) The program is designed to facilitate winter driving: starting the car in this mode takes place in second gear. It is activated by a pushbutton switch and the “ECT SNOW” indicator on the instrument cluster illuminates when the program is selected.
In addition, to use in the winter, it is a good help when starting on slides, the coating which consists of hard knurled soil or coarse sand and asphalt, can also be effective when driving on wet grass, asphalt.
When using it in winter, you should understand that you can get the maximum effect from SNOW mode only if you combine it with good winter tires.
MANU
MANU – The mode is intended for use in winter, when driving on slippery surfaces, to reduce the probability of wheel slippage. The car is driven from the second gear and shifts up at lower revolutions of the engine (1500-2000, 2500-3000 – figures differ depending on pedal pressure). MANU” mode as though “loads” reaction of a box, the car becomes “sluggish”, engine braking is carried out as much as possible that, certainly, is very useful in winter conditions. In summer, on asphalt, or when overtaking, it is better to switch off this model. When “MANU” is switched on, the “PWR” mode is automatically switched off. In addition, in “MANU” mode, the selected gear is forcibly fixed and all automatic gear shifts are not carried out. Fuel consumption is reduced, which is why it is sometimes referred to as “Economy mode”. In addition, different car brands may have different names for this mode. Instead of the Toyota “MANU”, it can be called “SNOW” or “HOLD”.
OD
OD (Overdrive) – Permission to use fourth gear (or 5th for 5-speed automatic transmissions), upshift, is given by a special “OD” button located on the gear lever. If it is in the recessed position and the range lever is in the D position, upshifting is forbidden. Otherwise, the fourth (5th) upshift is allowed. The state of the control system when OD is forbidden (i.e. the button is pressed) is indicated by “O/D OFF” on the instrument panel.
In essence, “OverDrive” is the automatic transmission 4th gear (or 5th gear for 5-speed automatic transmission), and how to use it is up to you. If by automatic transmission operation it is visible that it often changes gears from 3-4-3, it is better to switch this mode off, i.e. to press the button. You may encounter this phenomenon if your speed mode is not constant and fluctuates within the range of 60-80 km/h, or if you ascend a prolonged hill. For example, forcing a mountain ridge car lacks 4 gears and should be switched to 3, after a short burst of acceleration again switches to 4 and after passing just a few dozen meters again should be switched to 3. In such a case, of course, you should refuse to use OD, and press the button on the gear selector.
OD is a good tool for saving fuel if you go down a tight ridge, if you disable OD, you will not need to break the car at all, as the car speed will be within 80 km/h, i.e. the engine braking occurs (at the moment of engine braking, fuel supply to the cylinders is reduced to nothing).
If it is possible to drive at 60 km/h or more, there is no need to turn off the OD (the button is depressed), it will also result in fuel savings and most importantly, it will allow you to go even faster and reach the maximum speed if you do not get scared before that time.
OD ON
OD ON, this means that the OD button is OFF and 4th gear (5th for a 5-speed automatic transmission) is allowed.
OD OFF
OD OFF means that the button is DOWN and O/D OFF is lit on the instrument cluster, i.e. the highest gear is disengaged.
KICK-DOWN
KICK-DOWN – KICK-DOWN mode – shift to a lower gear; it is realized by sudden pressure on the gas pedal, the automatic transmission then shifts down one or even two speeds depending on the driving speed. This mode is controlled by a special throttle connected by a cable to the throttle block. This mode is used when overtaking or when sharp acceleration is required.