If the automatic transmission is in emergency mode, this means that a failure has occurred in the box. At the same time, an icon lights up on the instrument panel, indicating that a problem has occurred. The box stops responding dynamically to pressing the gas pedal. The mode is protective. Its inclusion indicates the danger of more serious damage. At the same time, you can drive your car on your own to the nearest repair station. However, it is not allowed to operate the vehicle for a long time in this condition.
Causes
The automatic transmission goes into emergency mode due to the following reasons:
- Insufficient oil in the box. If it escapes through the gaps formed, the gearbox signals a problem.
- Problems in the operation of hydraulic devices.
- Damage to the box body.
- Wear of friction clutches.
- Problems with the electronic control system.
Sometimes when cold, the automatic transmission works normally, but when it warms up it goes into emergency mode. The culprit is a faulty temperature sensor. If the box unexpectedly enters this state, the cause may be an ordinary electrical wiring break.
Possible causes and solutions
Now that you have learned what an “emergency light” is, let’s look at the reasons why the automatic transmission goes into this very emergency mode. And there can be many reasons, from trivial to serious.
Transmission fluid level
The automatic transmission may go into emergency mode due to a low lubricant level. A lack of ATF in the box can lead to malfunctions of mechanical parts.
For example, blood pressure drops. This means that valves and clutches cannot switch with natural force, as under normal pressure. The automatic transmission will either delay changing gears or jump from one to another.
Such oil quickly becomes clogged with wear products. Rubbing parts are not properly covered with a protective film. Wear occurs faster. Chips and metal dust get into the liquid. The filter device is clogged.
Therefore, do not allow the ATF level in the automatic transmission to drop. Check the level every 10,000 kilometers, and after 50,000 km change the lubricant completely.
Check the automatic transmission for integrity. Leaking seals, a broken machine body - all this affects the reduction in ATF levels. Wear of the gasket between the engine and the automatic transmission is also accompanied by loss of oil.
Non-original ATF also causes the machine to fail. Therefore, buy oil in official stores and only the type that your automatic transmission needs.
Read
Where are the gas and brake located on a car with an automatic transmission?
Malfunctions of the hydraulics or mechanical part of the box
If the automatic transmission is in emergency mode, check the hydraulics and mechanical parts. Clogged valve tracks in the valve body also lead to failure of the automatic transmission, as does a low oil level.
Wear of clutches and steel discs leads to oil contamination and the domino effect is activated. Gradually the remaining parts of the machine break down. If you do not pay attention to the problem in time, you will send the box for major repairs a month after the first signs of problems appear.
If the automatic transmission fails immediately after warming up to operating temperature, then the fault is in the temperature sensor.
If the pump wheel fails or the turbine blades are broken, the automatic transmission reactor will not work. Since the oil pressure required for normal operation will drop. There will be no pressure - gear shifting will become tense or simply impossible.
Incorrect operation of the electronic control system
The ECU forces the emergency mode to be activated due to damaged cables or contacts, when the signal about the correct functioning of the automatic transmission components does not reach it.
Faulty solenoids also cause the machine to go into an inoperative state. But we will talk about them in more detail in the next block.
Malfunctions in the crankshaft, throttle, and air sensors lead to the automatic transmission constantly being in a faulty state. Such problems can only be diagnosed using a scanner and a computer with special software.
If you hear a dull knock when the selector lever is switched to the “Forward” position, this means that the input or output shaft rotation sensor has failed. You will find information on how to fix an error with the input or output shaft rotation sensor in this article.
Read
Adjustment, replacement and why a brake band is needed in an automatic transmission
If the automatic transmission goes into emergency mode and does not want to come out of it at all, even after resetting the error, then the fault lies in the automatic control unit itself. In this case, only replacing the device with a new one will help.
Write in the comments what problems you encountered when your automatic transmission was faulty.
Automatic transmission solenoids
The reasons why the transmission fails may lie in faulty solenoids. Solenoids are very sensitive to oil quality and pressure. Therefore, both experienced mechanics and I recommend paying special attention to the original lubricant for automatic transmissions.
Automatic transmission goes into emergency mode after warming up
This can be observed when accelerating a car or driving under a heavy load. The reason is a malfunction of the temperature sensor, which gives incorrect information by degrees. This malfunction can be eliminated by replacing the element.
Renault Simbol, Laguna and Duster
On such cars a box is installed - Dp0. In some cases, it enters the emergency situation. The sign “Gearbox Fault” lights up on the instrument panel. To fix the problem, it is necessary to replace the pressure solenoids. If one element fails, then it doesn’t matter, it’s better to do the procedure in pairs. Later you will not have to disassemble the unit again.
Subaru Legacy
The reasons may be as follows:
- Torque converter slipping. It slips. The node is changing.
- Stuck or soured solenoids. New elements are being installed.
- The need to adjust the throttle sensor.
If such actions do not lead to anything, you need to remove the negative terminal of the battery for 2-3 minutes and conduct a self-diagnosis of the automatic transmission.
Mini Cooper R56
An error message appears on the computer. Gears are engaged no higher than third. The following steps must be taken:
- check ATF level;
- view the error code.
Sometimes adding fluid to normal helps. In the worst case, the valve body needs to be replaced. H3: Peugeot 206, 307 and 308
Al4 box installed. When the mode is turned on, problems may include oil, solenoid valves or cooling. Sometimes the lack of liquid in the expansion tank leads to the inclusion of this mode. To eliminate the phenomenon, the amount of antifreeze must be added to the level. Then everything will return to normal.
BMW E39
Causes:
- The lambda probe has broken down. This is a rare malfunction and not all technicians can immediately find it.
- Error 98 is displayed, which means the crankshaft speed sensor is faulty. The element requires replacement.
- Control unit malfunction. It is necessary to look for the cause of the breakdown.
Many of these defects are associated with overheating of the box.
Almera G15
Occurs when the car operates under difficult conditions, for example, during wheel slipping or emergency braking. In this case, the box may be in good condition.
To remove the unit from this state, you need to turn the ignition key to the OFF position and wait for 3 seconds. Then set it to position M. Afterwards the box should return to working condition. If not, then the failure is more serious and the unit will need to be disassembled.
Hyundai Santa Fe 2 and Solaris
The activation of the emergency state may occur as a result of failure of valve No. 75. It is located behind the intercooler. After disassembly, it can sometimes be cleaned. If this cannot be done, the element should be replaced. After installing a new valve, the mode must be unlocked.
Audi 80 B4
May be due to a faulty oil temperature sensor. It is located on a cable that requires replacement. After installing the new element, the error is fixed.
Skoda Octavia
The box is malfunctioning due to the failure of the torque converter. Sometimes occurs due to electrical failure. It is necessary to remove the pan and replace the solenoid if it is burnt out. You may just need to change the wire through which the signal does not pass.
Mercedes Actros and w211 w220
Enters the mode due to the destruction of the brake band, clutch or failure of the valve body. The nodes must change. After automatic transmission, you can operate it in standard mode.
What is automatic transmission emergency mode?
Now let's talk about what emergency mode is. You have probably read about these cases or have already encountered such situations when the following lamps are displayed on the dashboard monitor, which may blink or freeze in one position:
- Hold;
- Check Engine;
- A.T.
These lamps go out after restarting the engine or resetting the error by removing the wire from the negative terminal of the battery.
Attention! I do not recommend resetting errors by removing the wire from the battery terminal. This way you do not eliminate the cause, but extinguish the symptom. By the way, for us, experienced mechanics, after such a reset it is more difficult to determine the real problem.
Sometimes emergency mode may be preceded by the following symptoms:
- start and movement of the vehicle only in third gear;
- jolts and jerks when shifting gears;
- you cannot switch the transmission to parking mode or reverse speed;
- warning lights are on;
- selector vibration when idle at traffic lights.
Read
What is better to choose: repairing an automatic transmission or buying a contract automatic transmission
As soon as you see or hear one of the listed symptoms, immediately take the car for diagnostics. I strongly do not recommend continuing to drive a car with an automatic transmission in the emergency lights.
Write in the comments what you do if the box displays an error on the display?
Repair and contract automatic transmission
Many car enthusiasts say that a contract automatic transmission will cost less than a major overhaul. Not really. When buying a contract one, you are taking a “pig in a poke”. Often used machines are sold after they have been fully restored. Such automatic transmissions do not last long and break down within the first year after the expiration of the warranty period.
You already know the weak points of your automatic transmission and understand what you need to be prepared for, even after a major overhaul. But the choice always remains with the car owner.
Write in the comments if you bought a contract automatic transmission and how many kilometers did you drive it?
