In recent years, from the car owners and forums to see some people reflect Prado’s low-speed gearing and setbacks, from the actual I came into contact with the various types of domineering, indeed this situation is not uncommon. Among them, 3.5 Prado with six full-time four-wheel drive is in the majority, and there are also some 3.5 Prado with six-gear time-sharing. LC150 fourth grade 2.7Prado, fifth grade 4.0Prado also have, not much. 4. 0 of LC120 has seen one. This happens more often in sixth grade 2.7Prado, sixth class 4.0Prado, sixth class 4.0land patrol, eighth grade 5.7land patrol and eighth grade LX570, but because they are mainly parallel imported models, and all of them are encrypted ECU computers, I only model and crack some of the sixth grade 2.7s domineering (see the effect post after 27 tunes in my previous version), sixth 4.0overbearing and eighth 5.7lu patrol, eight LX570. Most encrypted computers cannot be cracked because of their high cost, so they can only solve the impact and setbacks of a few cars that have cracked the computer. Cracked, solve the file impact and frustration of the code string written, it will be solved.
Directly to the point, problem description:
This situation mainly occurs at a low speed of less than 45, and even for some cars at a low speed of 60. When it is necessary to slow down to a low speed, especially at a speed of about 20, when the fuel is collected or put on the brake, or is about to stop, there is a “bang” or “clang”. The sound is loud and small, most of the sound is very loud, at the same time, the car body has a severe frustration impact, and some cars still have a strong sense of drag, like the impact of gear shift. It is also like the gap between the transmission system, the drivers all think that there is something wrong with the car. As long as you slow down to a low speed, it will almost always happen if you pick up the oil or give it to the brake. Now basically every day in urban areas, traffic jams, stop-and-go, frequent fuel collection or braking, shocks and setbacks occur repeatedly, very annoying, so many car owners sell their cars.
3.5overbearing AC60F gearbox, although the model is the same as the six gears of 2.7and 4.0, but the hardware details and procedures are very different.
As I just said, this problem mainly occurred in 15-17 full-time four-wheel drive 16 3.5 Prado, and some 18 and 19 time-sharing four-wheel drive 3.5 Prado. Let’s take 3.5 Prado as an example. Some cars are picked up, some happen a few months later, and some begin to happen after one or two years or three years. At first, they happen sporadically, then slowly and frequently, even every time. This is not the case for all 3.5, but there is a certain proportion. If there is something wrong with the car, it must be found in the 4S store, some 4S stores say it is normal, some 4S stores check and check several times, some change parts, some change oil, and the computer cannot find the fault code. Many car owners called the Toyota headquarters customer service center, but had to bear to open it.
3.5 brain of Prado gearbox, oil circuit board and shift solenoid valve
There are many reasons for the impact and setback, including, but not limited to, the following:
1. Half shaft damage or rubber sleeve damage
2. Transmission shaft damage or clearance, universal joint or expansion joint damage or lack of oil dry grinding clearance
3. The oil seal of the transfer box is damaged, the clutch or chain of the transfer box is damaged, and the power can not be distributed normally.
4. oil leakage in the transfer box, cracking and penetration of the rubber base of the transfer box, and the difference between internal and external pressure caused by blockage of the pores in the transfer box.
5. Differential wear or damage, poor distribution power transmission, abnormal torque and speed difference
6. Bearing damage
7. There is something wrong with the gearbox oil, too much or too little oil or the wrong label, too many maintenance cycles do not change the gearbox oil
8. There is a problem with the oil temperature and pressure of the gearbox oil.
9. The clutch piece of the gearbox is damaged and cannot accept and transmit power normally.
10. there is something wrong with the logic of the up-and-down program, such as rising too fast, falling too slowly, rising and falling frequently, and the torque connection can not keep up.
11. The distribution of torque between gears is unreasonable
12. The throttle is too dirty and accumulates too much carbon
13. The design of engine saving too much fuel.
14. There may be something wrong with the gasoline
15. Some wires and sensors are defective or damaged, and the signal cannot be transmitted normally, resulting in a lack of access to the heart.
16, etc.
My car’s engine compartment, 7GR-FKS heart, double injection and double cycle
For many reasons, it is troublesome to find, with my own 16 3.5 Prado, lift and road test, check and diagnose one by one. The first thing to rule out is 1-7. I seldom cross the country, cherish the car, and maintain it normally. The car produced at the end of 16 years is also relatively new. The half-axle rubber sleeve transmission shaft differential box bearing is screened one by one, no problem. 121415 is also excluded one by one, the throttle is washed regularly, for fear of problems, it is washed again, the endoscope has not accumulated much carbon, has been adding two barrels of oil, the wire is fine, and the voltage resistance of the associated sensor is no problem.
At the beginning, I lifted the car and checked the sound source of the frustration.
After the causes of hearing and touching are excluded, only those that cannot be heard or touched are left, 89101113. As mentioned in an early post, our 3.5overbearing engine and gearbox are derived from the power system of Lexus GS350 around 2003, which are double injection, double cycle, and are very similar in procedure. In order to deal with the increasingly stringent environmental laws, the popular purpose is to save fuel. Toyota has changed the engine and gearbox, and renamed the model, such as the engine to 7GR-FKS, the gearbox to AC60F, and so on.
Measure the working status of all the engine and gearbox sensors that may cause gearing setbacks. Hands and wrists and arms will inevitably burn many times and need to be paid attention to. Is it possible that some people will say that you can’t do cold car testing? No, the cold car and the hot car represent the different working conditions of the engine gearbox, and the problem needs to be solved comprehensively.
I also wondered if any insurance was not working properly. I bought several sets of 3.5 Prado complete insurance, and unplugged all the insurance tests of large and small safe boxes. If you haven’t experienced pulling out a small safe box, you can’t know how strangely flexible your posture can be, and the infinite sense of space below the 40-degree temperature clutch in Shenzhen, because you don’t pull out one or pull it all over again.
Whether a car is smooth or not has a direct and critical relationship with the power of the engine, the structure and logic of the gearbox, and the matching between the gearbox and the power, especially the last item, the matching between the gearbox and the power. this item is seriously ignored. This is why many high-powered cars with large engines, such as the 3.5TT Raptor and Japanese cars with low engine power, can be very smooth, such as the Corolla Ma San, where the match between the engine and the gearbox is crucial.
3.5 bullying gearbox oil circuit board drawing, removed the oil pan
Back to 3.5 domineering, Toyota’s top priority in designing the 3.5 overbearing power system is to save fuel to meet stringent environmental laws. The 1234 gear is not only rising rapidly, but the torque distribution and response efficiency of each gear are also very weak, even directly reducing the fuel replenishment map, how can there be a good secondary acceleration without fuel replenishment? In addition, 1234 liters, retreating too early, 4321 downshifting, and taking off too late are the inducements of gear-breaking shocks and setbacks.
3.5 the gear ratio of each gear of Prado gearbox, which is one of the calculation and reference bases for a lot of data of the gearbox.
Toyota has been sparing no effort to save fuel, such as the implantation of genes, such as the 1GR before 2009 is a single VVT, so the LC120 4.0 is very cool, after 2009 into a double VVT and LC150,1GR 4.0 is much softer than LC120, to 7GR 3.5, even softer. Although the data looks better, like the 7GR 280hp, five more than the 1GR, even if the torque is a little less, it is not so soft.
Compared with other car companies, Toyota’s variable valve timing and lift take a completely different path-in order to save fuel, the data are good, the total power is increased, the thermal efficiency is improved, and the exhaust emissions are better, but the car is difficult to drive. especially the commonly used range of less than 3000 revolutions, obviously tired on soft feet. Look at BMW’s Vavletronic, Nissan’s VVEL, Honda’s I-VTEC, although they all use VVT-like technology, but other people’s changes are not only to save fuel, but also to make their users comfortable and comfortable. Volkswagen Audi’s AVS, although low-power cars also use dual-injection double-cycle, tread is also soft, but there is also no double-injection step on the cool high-power version to choose from. Of course, you can say that the VQ engine with VVEL like G37 is not goodbye. Although 2GR-FSE ‘s VARIANT 7GR-FKS is soft, it is also another kind of survival and rebirth of 2GR-FSE. I would like to say that although many VQ models have said goodbye, Nissan immediately came up with the VCT engine, which is also to make its own users feel good. It goes too far, and it goes on and on. In any case, compared to the BMW-Benz intermediate car dare to use 3 cylinders, what 1.5T, what 1.3T, Toyota is still very kind.
Last year’s National Day was in Gannan.
One of the setbacks caused by the original fuel-saving design of the 3. 5 7GR engine is that it is almost impossible to hold between 2000 and 3000 rpm, which is precisely the commonly used speed range of our self-priming engine. If it is not within 2000 revolutions, there is an Atkinson cycle at low speed, or it will suddenly jump to more than 3000 revolutions with a lot of noise, a pull and a pull, the power connection will be interrupted, and a setback will certainly occur. Of course, you may not feel a setback when you drive slowly, but no one can drive slowly all the time.
Also, 3.5 is domineering because it is a new model, a new power system, and there are individual differences in assembly and hardware. This is why the same 3.5 domineering, some take the oil or brake and then give the oil after the impact and sudden setbacks, but some do not.
The photo of 7GR removing the engine cover shows the intake structure and high-pressure oil rail.
There is another reason, let’s talk about it for a while. 7GR and 2GR-FSE is a high-speed engine, drag such a heavy off-road vehicle low torsion is insufficient, so many car owners step hard to quickly reach their favorite or accustomed speed, cross-country need to step harder to get high torsion, which increase the load of the gearbox, resulting in high oil temperature and oil pressure of the gearbox, over time, the gearbox valve body and oil circuit board work abnormally. According to one data, when the oil temperature of the gearbox exceeds 115 degrees, the shift logic of the gearbox will change. If Toyota had given the low twist of 7GR a little more when designing and developing 3.5, I believe that the probability of such misses and setbacks would be much lower than it is now, of course, Toyota would not do so, and it would not be enough to save fuel. That’s why I adjusted the 3.5 domineering low-speed torque distribution a little more, while calculating and matching the gearbox’s shift logic and testing it over and over again. Over the past three years, I have trained my own 3.5 overbearing gearbox program more than 200 times.
Looking for the specific sound source of the shock and setback with a “bang” or “bang”, the process is a little worried. Because there are both 1234 and 4321 liters and downgears, the maximum speed point goes to 60, and my car is lifted, just on the lift, not fixed, because I have to stand under the car to listen, so it rises very high, and if I step on 60, the car will shake. If you are not careful, you will step on 80, and you have to step on it again and again, because you can’t find the sound source at once. Either sitting in the car in a panic, or standing under the car to listen for fear of the car falling down. When excluding the transfer box and the front and rear axle tooth bag, I listened to it dozens of times under the car for fear that I would not carefully miss the real reason.
Transmission logic map diagram
After that, the continuous road test found out the main trigger points and areas of the speed and speed of the gear-breaking impact and sudden setback, combined with the gearbox program, matched with the engine program, and trained more than a dozen versions of the program in 19 years, which basically solved this problem. There is always a version that can solve it. But can only be solved in the lower torque version, always feel imperfect, and now every day traffic jams, gear shocks and setbacks will occur occasionally, it is like a thorn in the body, do not take it off completely, I have not been reconciled.
Transmission logic map diagram
So 19 years so far has been constantly training, trying to solve. But it is really too difficult and very time-consuming, because it has at least three variables: rotational speed, speed and gear. Under the rotational speed and speed of 1234 and 4321, a break impact and sudden setback may occur. The head is big to calculate the number of permutations and combinations, and float up according to the gourd. Solve one point after another, solve one point and another, like an endless road that needs to be constantly tested and accumulated. During this period, failure, frustration, unwillingness to hope and anxiety go up and down, indescribable.
Maps diagram
Maps diagram
In order to solve it, we compared almost all Toyota Lexus 6AT gearbox programs, U660E, U661E, A760E, A960E, A650E, etc., old and new, their data and working logic, as well as the torque distribution of the engine, and compared them N times. It was not until the end of last year that the maps that triggered the shock and setback were finally accumulated, and the corresponding maps solution was also established. No matter which speed, speed, gear, or torque version, the code string was written in, More than 98% of the shock and setback will not occur again. After several long-distance tests around the Spring Festival and more than 5,000 kilometers, neither the impact nor the setback occurred again.
maps
maps
The maps that once pressed the gourd and floated the gourd, BAI OCTAL, DECTIMAL, and HEXADECIMAL, went from beating to quiet, and gradually no longer embarrassed me.
Under Toyota’s car series, the words on the Prado model have been marked with “discontinued”
3.5 Prado’s anti-collision beam is made of full materials and firmly stands in front of the beam, providing solid and solid protection for 3.5 overbearing car owners.
Toyota’s cars have always been known for their smoothness and durability. Overbearing is Toyota’s benchmark product and a fluttering flag. Toyota has made a lot of efforts in order to ensure that the car can continue to exist in China. Even so, in the face of the rolling tide of environmental protection, the life of the bully in China came to an abrupt end last year. The overbearing production line has been given to other models, fewer and fewer shops and masters are familiar with overbearing maintenance and repairs, and overbearing topics and pictures will become less and less common. Even under the Toyota car series of our Aika, the text of the Prado model has been marked as “discontinued”, like a shadow of a distant era. To use an old saying, I wish you all overbearing drivers, drive and cherish it.
The total mileage of my car is 125680 kilometers.
ZebulonReynolds 
3 
September 16, 2024 
