Terracan tod

Sasha on Tarakashka thanks for the answer, but the question immediately arose for what purpose are there two signs of the transfer case on the panel and how can I check the operation of the AVTO, and how can I check the oil in the transfer case, is there a dipstick somewhere? I ask a question because I have the whole bottom in protection like on an armored train, I need to shoot everything, but I wanted to know in advance. Thanks in advance for your reply.

I will make a reservation right away that I don’t remember something. More than a year has passed since Tarakashka and I broke up.

There are always two icons on the panel. As far as I know, they work for ECT. It seems that when LOW is turned on, the corresponding symbol lights up on the panel. In the event of a system malfunction, the “spider” blinked – a symbol of all-wheel drive.

In the razdatka, however, as in any gearbox, the oil level must be up to the filler hole.

The operability of AUTO, most reliably, is checked as follows: raise both rear wheels and place them under the stand frame. Try to move. If the car goes on one front, the system is working. It is possible, just as abruptly, to move on a slippery surface, on ice, or, at worst, on the sand. Here you will need an assistant who will monitor the behavior of the front wheels. The method is not so reliable, since the jerk of the front end may not be noticed.

Modified on October 21, 2011 by Sashka on Tarakashka

So let’s start by praying!

Transfer cases, or if it is correct, transfer boxes, installed on Korean-made cars, which include Nyundai Terrakan, were of two types. Full time (constant full) – TOD and part time (connected full) – EST. The external difference is very simple! This is the number of positions of the washer that controls the transfer modes. TOD has two positions: AUTO and LOW. ECT has three of them: 2H, 4H and 4L.

What’s the difference? TOD distributes torque across the axles automatically. That is, the front end is connected as necessary without the participation of the driver (switch position in AUTO). And it never turns off completely. Even when moving in a straight line, at a constant speed, a tiny part of the torque, no less than five percent in size, still comes to it. The distribution is smooth up to 50×50 in the mud, or when you turn on the lower row in the transfer case ( switch position in LOW ), when the front end is connected rigidly and the automation is turned off.

A completely different picture with ECT! Here the driver himself is in charge of connecting the front end. As a rule, most of the time a car equipped with this type of transfer case is operated as a conventional rear-wheel drive (switch position in 2H). When driving off-road, or on ice, the front-wheel drive is connected (switch to 4H), and in a very difficult case, a lower gear (4L).

Now I’ll tell you how to properly manage the transfer case.

TOD. We drive AUTO and don’t think about anything! When the moment comes to turn on the front end, we stop, keep the brake and clutch pedals pressed, the gearbox to neutral (automatic transmission to park) and, without releasing anything, turn the switch. F DYOM for about five seconds. NOT RELEASEING ANYTHING (!). The LOW icon should light up on the panel. Everything, reduced included. Shutdown is carried out in the same way.

ECT. We go to 2N. If necessary, connect the front-wheel drive, simply turn the switch to the 4H position. At the same time, the corresponding icon on the panel will tell you that the device is turned on. However, it must be taken into account that the ECT does not have a center differential. Therefore, it will be somewhat difficult to maneuver on a dry surface on a full drive. And the maximum speed of 80 km / h should not be exceeded! The reduced one turns on and off in compliance with the same requirements as for the TOD.

Well, it seems I haven’t forgotten anything. If anything, the guys will correct me and supplement. And if you still have questions ON OPERATION (talks about the device and repair IN OTHER TOPICS!) handout, ask without hesitation!

An “ATT” (Active Torque Transfer) or “TOD” (Torque-on-Demand) system is classified as a “4” system. This is an all-wheel drive system with active torque distribution between the front and rear axles, which allows you to increase the vehicle’s cross-country ability. Torque distribution occurs depending on:

– vehicle driving conditions (off-road, slippery or normal road);
– vehicle driving mode (acceleration, braking or uniform movement);
– load on the engine;
– And so on.

The system consists of:
– sensors (frequencies of rotation of front and rear cardan shafts) and switches;
– electronic control unit;
– actuators (electromagnetic clutch, electric motor).

Transfer box control scheme.

Note: abbreviations in the figure indicate:

– electronic control unit;

– electromagnetic clutch;

– throttle position sensor signal

or accelerator pedal position sensor signal ;

– anti-lock brake system signal ();

– stoplight switch signal;

– relay signal of the gearbox neutral sensor-switch.

Speed ​​sensors detect the speed of cardan shafts and transmit a signal to the control unit.

The control unit, based on signals from sensors and other control units, determines the state of the elements of the vehicle control systems and driving conditions. In accordance with the internal algorithm, the unit decides on the ratio of torques on the front and rear wheels and sends control signals to the actuators.

The electromagnetic clutch installed in the transfer case is responsible for the compression force of the friction discs in the multi-plate clutch. At the signal of the control unit, the clutch either increases the compression of the disks (which ensures an increase in the torque supplied to the front wheels), or reduces the compression force of the disks, which leads to a decrease in the torque on the front wheels.

The electric motor is responsible for downshifting. Downshifting is carried out when the operating mode switch is moved to the “” position.

The torque ratio between the front and rear wheels is not a constant value, but varies depending on the driving conditions. The ratio can be changed from 0:100 (front : rear) to 50:50. Thus, the torque on the front wheels cannot exceed the torque supplied to the rear wheels.

The system sets the torque ratio to 0:100 only when driving at low speed on good roads. In other cases, the system, depending on the conditions, brings part of the torque to the front wheels and in difficult driving conditions the torque ratio reaches 50:50 (front : rear).

Power flow in “” mode.

System operation modes

Switching between the operating modes of the system is carried out using a switch that has two positions: “” and “”.

In this mode, the electronic control unit is responsible for the distribution of torque between the front and rear wheels and, depending on the driving conditions, either all the torque can be supplied to the rear wheels (driving on good roads at low speed), or distributed in a certain proportions, depending on driving conditions (see table “Torque distribution by the system depending on driving conditions”).

This mode is the main mode for driving, because the control system automatically selects the necessary parameters. However, when driving off-road, it is recommended to turn on the “” mode.

In the “” mode, a downshift is activated by the signal from the control unit and the torque is distributed in a ratio of 50:50 between the front and rear wheels.

This mode is recommended for driving on bad roads and off-road.

When the “” mode is activated, the downshift indicator on the instrument cluster lights up.

It is not recommended to use the “” mode when driving at high speed and driving on ordinary roads, as this could damage the transmission.

Table. Distribution of torque by the system depending on driving conditions

: “*” – takes into account the difference in the speed of rotation of the front and rear cardan shafts.

Alexander Rodionov, Mikhail Goncharenko,

Hyundai Terracan – TOD (ATT) system

An “ATT” (Active Torque Transfer) or “TOD” (Torque-on-Demand) system is classified as a “Full Time 4WD” system. This is an all-wheel drive system with active torque distribution between the front and rear axles, which allows you to increase the vehicle’s cross-country ability. Torque distribution occurs depending on:

TCCM – electronic control unit;

EMC – electromagnetic clutch;

TPS – Throttle Position Sensor (G6CV) or Accelerator Pedal Position Sensor (J3) signal;

ABS – anti-lock braking system (ABS) signal;

BR – brake light switch signal;

N – relay signal of the gearbox neutral sensor-switch.

The electric motor is responsible for downshifting. Downshifting is carried out when the operating mode switch is turned to the “LOW” position.

Power flow in “AUTO” mode.

Power flow in “LOW” mode.

TOD system operating modes

Switching between the operating modes of the TOD system is carried out using a switch that has two positions: “AUTO” and “LOW”.

In this mode, the electronic control unit is responsible for the distribution of torque between the front and rear wheels and, depending on the driving conditions, either all the torque can be supplied to the rear wheels (driving on good roads at low speed), or distributed in a certain proportions, depending on the driving conditions (see table “Torque distribution by the TOD system depending on the driving conditions”).

This mode is the main driving mode because the control system automatically selects the necessary parameters. However, when driving off-road, it is recommended to turn on the “LOW” mode.

In the “LOW” mode, the signal from the control unit engages a downshift and the torque is distributed in a ratio of 50:50 between the front and rear wheels.

When the “LOW” mode is engaged, the downshift indicator on the instrument cluster lights up.

It is not recommended to use the “LOW” mode when driving at high speed and driving on ordinary roads, as this could damage the transmission.

Table. Distribution of torque by the TOD system depending on driving conditions

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Age: 55
Auto: Terracan 2.9 automatic transmission super TOD (2Hi, Avto, 4Hi, 4Low) 2002
City: Dolgoprudny
Posts: 771

Current is only 4.12A at 14V For comparison: The current on a 55W lamp (one foglight) is 3.8A

If so, then it remains to assemble a primitive electrical circuit and introduce it into the car. The first time I did and installed a two-position circuit on my car1. T OD – in normal mode on demand.2. Clutch lock. I had no complaints about the work, I rode with this scheme for two months. By the way, the book says that on LOW the moment should be 50 to 50, I didn’t even observe this with new disks, I conducted research by hanging the rear axle beam on wooden blocks, the rear axle was spinning and only the “slipper on the floor” allowed me to pull off the front end cars from logs. After talking with the owners of cars that have TOD, I concluded that the system works differently for everyone, for someone the connection of the front axle begins to be felt at a speed of at least 3000 (like mine), for others almost at idle engine speed, with sharp turns, the inclusion of the front end on the steering wheel is already felt. At the request of teammates, I made a diagram for three switch positions: 1. T OD-disabled – torque is not transmitted to the front axle 2. T OD- in normal mode on demand – for wet asphalt, winter and light off-road3. Clutch lock 50 to 50 – for ice, snow and off-road, but when LOW is too early to turn on. Subsequent practice has shown that in the off mode, many even experience a small fuel economy. I also think that the transfer discs, the chain, the front axle gearbox will last much longer, and the ease of driving on a paved road will noticeably improve. You can enable, disable the lock and disable TOD at any speed (tested on my car, and already on many others. On a paved road, it is imperative to disable the lock to reduce the load on the transmission.

“Guys! And you can find out – what is it for you? You don’t drive on asphalt at all, do you? And to ride through the mud, there is a good saying: “If you don’t know the ford, don’t stick your head into the water.” I feel sorry for my cockroach to meddle somewhere. Electronics is a tricky thing. How not to harm any alterations. Say winter management is more reliable. What’s the head for. After all, you can drive more quietly. ”I will try to answer so that everyone, including me, understands.

First of all, after acquiring a car, I fell into the shit, they pulled me out of there in disgrace and not with my foot anymore. And I burned the discs, I think, in just a couple of times, pulling friends out of the snow who came to visit me in the winter at the dacha, in the bathhouse. Three cars couldn’t get to me in my footsteps, I had to drag them, but not leave them. By the way, out of ignorance, I pulled them out in reverse, which is why I burned the discs. Quote from Baste “Reversing is much more harmful, especially long slips, in this case the pump sucks everything that was in the shaft and pours the transfer cases into the crankcase and the clutches work dry (much easier to burn)”

There was another question. And how is it that with a power of 60 W, the coil is able to hold a clutch that transmits a moment of 600 Nm at Low? Dmitry Baste simply answered this question superbly: “It is not an electromagnet that compresses the disks, but balls moving along the grooves. until the speeds equalize and the load disappears. (pure mechanics)” And with the TOD dispenser, the “fathers – parents of the Korean auto industry” were clearly too smart. I don’t know about others, but I really don’t like that the transfer of moment is carried out due to the slippage of the friction discs. With a large difference in the speed of the bridges, the disks, in my opinion, should be tightly coupled to transfer the moment 50 to 50, and when the speed of the bridges is equalized, they should disengage. TOD can transfer only 88% of the moment to the front axle, and for this you need to fulfill many conditions (high speeds, difference in rotations of cardan shafts, etc.) To make it more clear, it turns out, as it were, constant driving with the clutch half depressed. In my opinion, complete absurdity. For more than a year, Uncle Lyosha ColonelU convinced me that there was such a thing, but I still could not understand. Is that possible? So, installing this scheme on a car allows you to: – multiply the resource of the clutch disks (the disks will clutch tightly, and will not constantly compress – decompress) – increase the car’s patency, make it possible to move in 4H mode, at any engine speed – increase the reliability of the connection system 4H mode (the control unit is not involved in this) – it will be possible to turn on the 2H mode from the driver’s seat, and this will reduce wear: transfer chains, front axle gearbox, CV joints, tires; steering will become easier on a dry hard surface. And most importantly, faith in yourself and in your car will increase. I liked how it is written on the side glass of someone’s Haloper “a person is given the right to move where he wants” (maybe not literally, but the meaning is the same). And so, why do we need a large frame ZHIP, on which you can’t drive where you want, but the head, of course, is needed everywhere.

To change this post, I used links to research and thoughts of various authors. Thank you so much!!!! Dmitry Baste and many others. http://supertod.a5.ru/