Automatic transmission selector and automatic operating modes

To control the gearbox, a mode selector and, possibly, additional control buttons are installed in the cabin. With their help, the driver has the opportunity to set such a sequence of automatic gear changes that best suits the driving conditions.

It should be noted that for safety reasons, the automatic transmission only allows the engine to be started in the "N" or "P" position. On models that lock the transmission selector when the ignition is off, the ignition key must be turned from the LOCK position (steering wheel lock) to the ON position (ignition on) before moving the lever out of park position P to unlock both the lever and the steering wheel . Otherwise, the steering column or range selector may be damaged.

Each gear change while driving will be accompanied by some reduction in engine speed. Only in this case, it must be borne in mind that the tachometer needle reacts in the same way to the blocking of the torque converter (however, the drop in speed in this case will not be as noticeable as during gear changes - see below).

P-R-N-D-3-2-1, Hold, Power is possible modes machine operation. These also include a small button near the selector (if any) and a large mode lock button (switch limiter) on the selector.

The service black button at the selector (if, of course, there is one) when pressed, allows switching with the ignition off. For example, by pressing this button, you can move the lever to "Neutral" (N) to push a non-starting car. In a car service, removing dashboard or by setting new radio, in the same way, you can also move the lever, say, to position "1" for easier access to the console. And on some models without it, it is difficult to shake out the ashtray.

P - Parking or parking - serves to keep the car in the parking lot. You can switch to this mode only when the car is completely stopped. Accidental switching to this mode is blocked by a button on the selector of the machine.
In the gearbox in this mode, "neutral" is set, which provides a normal engine start mode. In this selector position, the gearbox shaft is blocked by a special hook and the front wheels do not spin.
It is not recommended to leave the car only on P if the slope exceeds 10-15% (more than 5 degrees) - this threatens to “bite” the parking stop. An easy way to determine the acceptable parking angle without a handbrake on a working box is to let off the gas and see if the car rolls backwards.
When stopping on slopes, press the brake pedal, move the selector to N, depress the handbrake, release the brake pedal, and only then put the selector to P. Move off the slope in the reverse order. Squeeze out the brake, put the selector in D, then release the handbrake and start moving, throwing your foot from the brake to the gas.

R - Reverse - reverse. You can switch to this mode only when the car is completely stopped. Random switching is blocked by a button on the selector of the machine.

N - Neutral - neutral gear. In this position of the selector, the car, as well as on "P", can be started, but the shaft does not block. However, it differs from the neutral mode on manual gearboxes. In this mode, you cannot roll downhill or tow the machine with the engine off without risking damage to the machine. The fact is that oil pump located on the input shaft of the automatic transmission, so when the engine is turned off, it will not work, which means there will be no ATF circulation and the box may overheat.

There is an opinion that, standing at a traffic light, you should go to "N", because in the "D" mode something slips and wears out there. In fact, this is not so, all the elements of the box are immobilized, the clutches are clamped, the first gear is engaged and only the pump pumps the transmission fluid idle. In this case, the movement begins without slipping of the friction pairs, which come into operation only when switching to second gear. The transition from the "N" mode to "D", on the contrary, makes them work harder.

In addition, when transferring the selector from the "N" to "D" mode, you should not immediately press the gas, but you need to wait for a characteristic push, which will show that the box has entered the driving mode and selected the desired gear, and in the heat of the rush you can forget about it.

So it is not recommended to use the "N" mode, except when restarting a stalled engine, as well as towing the car or rolling it manually with the engine off. At short stops, for example at a traffic light, the selector should not be moved to either the "N" position or the "P" position, and in such cases the vehicle should be kept in place with the help of the brakes. If, during long stops in traffic jams, your leg is tired, then it is better to immediately set the "P" mode. You can also do it when stopping in hot weather to reduce heat generation and prevent overheating of the ATF in the box.

When driving on long descents, it is not recommended to set the selector lever to the "N" position. This will not save fuel, but may cause the box to overheat when returning to D for high speed.

So when coasting, it is better to leave the selector in the position in which it was before. In this case, the box will switch to the highest of the permitted gears and provide minimum braking engine. If you rolled in "N" mode, the subsequent transition to "D" will make the box wait to enter the driving mode, since it needs time to shift into the desired gear.

Switching the selector lever before starting the movement and when changing direction (forward-backward) must be carried out with the brake pedal depressed and the car completely stopped. Start moving, removing your foot from the brake pedal and transferring it to the gas pedal, should only be after a characteristic push, indicating full inclusion transmission.

The drive mode selector lever is designed to allow shifting without depressing the detent, both when planing from a standstill and while driving. That is, everything that switches without pressing the large button on the selector can be switched on the move without restrictions, and what does not switch without pressing this button requires certain precautions.

So, for example, if you need to move the handle from position "N" to position "D" or "3", then this can be done by simply pulling it towards you. Or if you want to move the lever up from "1" to "2", "3" or "D", then this can be done without any restrictions in movement (just try not to jump into "N" while doing this - this is not dangerous, but unpleasant).

However, if you want to move the lever from position "3" to position "2" or "1" or, even more so, to position "R", then without pressing the latch you will not succeed. This is done to prevent breakdowns and overloads of the transmission when the driving mode is selected incorrectly. Setting the lever to the position where it can be moved only with the locking button pressed, is carried out either after a complete stop (if you need to set "R" or "P"), or after slowing down (if necessary, set "2" from "3" or "one").

D - DRIVE - the main mode of operation - driving is allowed in all gears (there are 4 of them in this machine): first (1), second (2), third (3-direct, with gear ratio 1), fourth (4, which in these machines can be called overdrive (overdrive), since the gear ratio is less than one - 0.69). The fourth gear in automatic transmissions is similar to the fifth in manual boxes, that is, it is an overdrive, unlike the third, which is a direct gear. In addition, in D mode, the torque converter quickly locks up (see "Note on torque converter lockup"), which is favorable when driving on the highway (the consumption decreases by 1.5-2 liters), but extremely undesirable in the city (the reaction to the gas pedal becomes sluggish ).

Notes:

During long climbs (when moving up an inclined plane)

Unwanted upshifting at the moment of releasing the accelerator pedal when driving on long hills is automatically prevented. This reduces the need to downshift when you hit the gas again if you feel a lack of power. It also prevents multiple gear shifts and results in smoother climbing.

During long descents (when moving down an inclined plane)

Pressing the brake pedal downhill will automatically cause the transmission to shift to a lower gear (when driving in D - to 3rd), thus causing some engine braking. However, even short-term acceleration will cause the transmission to shift normally into upshifts.

However, in some cases, pressing the brake pedal on descents does not lead to automatic switching transmission to a low gear This can occur due to very low temperatures transmission fluid e.g. after a long parking. In this case, until the temperature of the ATF rises to about 60 degrees, manual downshifting will be required to brake the engine.

Also, the transmission will not downshift at speeds greater than 78 km/h.

If possible, do not use mode D in the city, especially in winter - by forcibly excluding overdrive and the possibility of blocking the torque converter, you make the car more "alive" (the automatic transmission switches down faster when overtaking and changing lanes) and, in addition, you can use the mode more efficiently engine braking when releasing gas. Remember that automata like Subarovskih (with overdrive and torque converter lockup, allowed in the selector position D), some observers call "brake" precisely because when trying to accelerate on the D box, you often have to first unlock the torque converter, and then also switch up transfer down, which, understandably, takes some time.

In addition, by eliminating the highest gear in the city (by setting the selector to 3), you avoid unnecessary shifts and frequent engagement of the torque converter lock-up, which prolongs the life of the automatic transmission (frictions and brake bands) that you will need on the highway.

And, finally, the exclusion of mode D from use is recommended for owners of "prone to overheating" engines with a volume of 2.5 liters. Dynamic driving is an additional benefit for them and serves to improve engine cooling!

Do not turn on mode D when the car is fully loaded (set the selector to 3).

When driving in traffic jams, when the movement is “ragged” and frequent gear changes occur, in order to prevent increased wear of automatic transmission parts, turn off mode D (set the selector to 3 or even to 2).

It is also useful to know that on an unheated box, top gear is not engaged and the torque converter is not blocked. Accordingly, a faulty thermostat or severe frost may prevent the inclusion of a higher gear, since the initial warm-up comes from the ATF radiator, which is located inside the engine coolant radiator reservoir. Normal automatic transmission mode is activated when the ATF temperature is more than 60 degrees.

Modes (1), (2), (3) allow you to use gears up to and including the specified one, but not higher. The modes may depend on the HOLD / MANU button (see "special automatic transmission modes").

3 - direct transmission with a gear ratio of 1. By transferring the selector to (3), we translate the automatic transmission into 3 speed mode, i.e. 1st, 2nd and 3rd gears are involved in the work and the torque converter is not blocked. Recommended for city driving.

The permitted maximum speed in this gear is 152-154 km/h.

2 - gear with a gear ratio of 1.55. As well as mode (3), it usually limits the transmission from above, that is, only 1st and 2nd gears are included.

However, on some models (mainly for American market, where as few additional buttons as possible for switching modes are traditionally displayed) when (2) is selected, the box itself goes into "winter mode" (see " Special Modes Automatic transmission"), i.e. it starts off from second gear and does not switch down.

Mode (2) is needed for driving on slippery surfaces, off-road or for towing heavy trailers. In addition, when driving on (2), more effective engine braking is provided when releasing the gas. Therefore, you can include this range to overcome a long slope or when driving on steep descent when engine braking is required to maintain control of the vehicle.

The permitted maximum speed in this gear is 91 km/h.

1 - special gear with a high gear ratio of 2.79 and a lock center differential on the all-wheel drive models. This mode is used when a large torque is required without high speed movement.

It is not recommended to drive in this mode for a long time. Also, turning in this mode can cause the center differential lock clutch to fail. It is recommended to use only when driving in a straight line at low speed, driving out of snow, sand and mud, on long, very steep hills and long descents, especially when driving with a trailer. In addition, in first gear, an effective engine braking mode is provided.

The permitted maximum speed in this gear is 44 km/h.

When limiting the switching range, try not to exceed the setting for maximum gear this range limiting speed;

Forced downshifting using the range selector can only be performed at vehicle speeds that do not exceed the maximum allowable for the limiting gear. Structurally, the transmission is designed in such a way that it involves the use of the first gear at speeds not exceeding 50 km / h with the gas pedal fully depressed (30 km / h with half pressure), and the second gear, respectively, at about 90 km / h with full and 60 km/h at half pressure. And switching from "3" to "2" is unacceptable at speeds above 70-80 km / h, so the range-limiting selector does not switch from the range "D-3" to "2-1" without pressing the blocking button. However, in modern automatic transmissions, downshifting is still corrected by the control controller and will not bring much harm even in the event of an invalid selector translation.

When stopping on a hill, do not attempt to hold the vehicle in stationary position by adjusting the traction force with the accelerator pedal. This can cause the automatic transmission to overheat and fail. Use the brakes to keep the vehicle on a slope.

Trying to pull out a stuck car by rocking, alternately including first gear, then gear reversing, in order to avoid damage to the automatic transmission, do not press the accelerator pedal hard (the speed when slipping wheels should not exceed 30 km / h on the speedometer.

AND MOST IMPORTANTLY!!! READ THE MANUAL FOR YOUR (!!!) CAR AND LEARN TO USE THEM!!!