The situation when a car refuses to start at the most inopportune moment is familiar to many drivers. A discharged battery is one of the most common causes of such trouble, especially in the cold season. Owners of cars with a manual transmission often know how to act, but the question is: Can I light up on the machine?It still causes fierce controversy in garages and car forums.
There is a persistent myth that the automatic box somehow reacts in a special way to power surges or start procedure from an external source, which can lead to fatal consequences for the transmission. Actually, gearbox (AV) is mechanically untied from the starter and battery at the time of engine start, so there is no direct threat to the hydraulic transformer or planetary rows in this process. However, the risks still exist, but they are primarily related to complex problems. electronics and on-board control systems, which modern cars are stuffed literally to the point of failure.
In this article, we will examine the physics of the process, the possible implications for the smart car systems and provide clear instructions on how to safely resuscitate a machine with automatic transmission. You will learn why the order of wires is critical and what errors can turn a small battery problem into an expensive control unit repair.
Process physics and impact on automatic transmission electronics
To understand whether it is safe to light a car with an automatic box, you need to consider the electrical circuit of a modern car. The starter that spins the engine is connected directly to the battery via power wires and relays. At the moment of launch, it consumes a huge current, but this current passes through circuits that do not directly affect the controllers. transmission.
The automatic transmission is controlled by a separate electronic unit (TCU), which receives power from the onboard network. When you connect the donor, there may be power surges in the network. Modern cars are equipped with protection systems, but cheap or old models can be sensitive to changes. That is why there is an opinion about the dangers of cigarette lighting, although in fact it is not the box itself that suffers, but rather the box itself. electronicswhich may fail if mishandled.
It is important to understand the difference between mechanical and electrical parts. Mechanically, the “automatic” does not care how the crankshaft spins – from your battery or from someone else’s. Problems only begin if polarity is broken or sparked when the circuit is broken under load. Pulse surges The main enemy is the voltage, not the type of transmission.
Always use only high-quality start wires with a cross section of at least 16 mm2. Thin wires may melt or not provide enough current to start the engine in the cold.
Thus, there is no direct correlation between the type of transmission and the possibility of lighting. You can use this method if you follow safety precautions. The main thing is to avoid mistakes that are dangerous for any car, regardless of whether it is there. hydromechanical, a variator or a robot.
The main risks and myths about starting the engine
Despite the technical possibility, there are many horror stories around the procedure. One of them says that when lighting can burn the control unit automatic transmission. This is partly true, but only in the case of gross violation of the rules. If you confuse plus and minus, the current will go wrong where it should, and will disable fuses or expensive ones. controller. But this risk is not specific to the machine, but common to the entire onboard network.
⚠️ Warning: Never connect the wires when the engine of the donor car is running unless you are sure of the voltage stability of its generator. A power surge can instantly kill the recipient's electronics.
Another common myth is the need to remove the battery. In older cars, this is sometimes recommended, but modern cars with their complex energy saving systems and settings memory can react extremely negatively to a complete shutdown. Removal of terminals in the process of lighting is not required and is not even recommended, since the battery acts as a huge capacitor that smoothes the pulsation of voltage.
There is also a misconception that the machine can not be started “from the pusher”, and therefore you can not light. It's two different things. Starting from a pusher on an automatic machine is really impossible (or extremely difficult and harmful), since to create pressure in the system you need a running pump, which the engine spins. And when lighting, we just start the engine with a regular starter, so there are no problems with the lighting. hydraulic-box It doesn't happen.
Preparation for the procedure: verification and safety
Before grabbing the wires, it is necessary to conduct a thorough visual inspection of both cars. Make sure the batteries are working, do not have cracks and electrolyte leaks. If the battery is frozen (swelled), light it up. forbidden - it could explode. In this case, the battery must be brought into the heat or replaced.
The donor car should be warmed up. Let it work 5-10 minutes at a rpm of about 2,000 rpm to charge its battery. This will create a reserve of energy for a confident start. It is also important to silence all energy consumers on both machines: headlights, tape, climate control, heating. This will reduce the network load at the time of launch.
- 🚗 Place the cars as close as possible, but without contact of the bodies, so that the wires reach without tension.
- 🔌 Make sure that the ignition on both cars is turned off and the keys are removed from the locks (or are outside the range of keyless access).
- 🧤 Use protective gloves and glasses whenever possible, especially in the cold when the plastic becomes brittle.
Pay special attention to the search for connection points. On many modern cars with automatic transmission, access to the battery terminals can be hampered by plastic casings or shifted into the trunk / under the seat. In such cases, the manufacturer provides special connection points under the hood: plus contact (often closed with a red cover) and mass (bolt on body or engine). Find them in advance by reading the instructions for your model.
Step by step instructions: how to light the machine correctly
Compliance with the sequence of actions is the key to the success and safety of electronics. Any deviation from the algorithm can lead to a spark or a voltage surge. Below is a universal instruction that is suitable for most cars with automatic transmission.
☑️ Algorithm of wire connection
First, connect the positive (red) wire to the plus terminal of the discharged battery. Then, the second end of the red wire is fixed on the plus of the donor car battery. Now we turn to the "minuses." Connect the black wire to the donor's negative terminal. The second end of the black wire is fixed on the unpainted metal part of the engine or body (mass) the vehicle to be started. This is done so that the spark (if it slips) is away from the battery vapor.
Start the donor's engine and let him work for a few minutes. Then try to start a car with a dead battery. If the engine is caught, do not shut it down. Now you can gently disconnect the wires in the order, backwire: first minus from the machine, then minus from the donor, then pluses. It is important not to allow each other's wires and body to touch during removal.
⚠️ Attention: At the time of disconnecting the wires, the engine of the started car must work. Do not shut down the engine immediately after starting, give the generator time to start charging the battery.
What if the car didn’t start the first time?
If the starter spins sluggishly or does not spin at all after connecting, do not try to spin longer than 5-7 seconds. Allow the donor’s battery to recharge the dead battery for 10-15 minutes with the donor’s engine running. Try again. If the starter does not respond at all – check the quality of contacts on the terminals, perhaps oxidation interferes with the transmission of current.
Table: Comparison of risks for different types of cars
Not all cars respond equally to external interference with the power grid. Below is a comparative characteristic that will help you assess the degree of risk depending on the class and age of your automatic vehicle.
| Type of vehicle | Risk for electronics | Features of connection | Recommendation |
|---|---|---|---|
| Older cars (until 2005) | Low. | Direct access to the BAC | You can light it standard. |
| Middle class (2010-2018) | Medium. | Lots of electronics. | Maintain strict consistency |
| Premium/Hybrids | High-pitched | A complex BMS system | Use a booster or service |
| Car with Start-Stop | Medium. | AGM/EFB type battery | We need a powerful donor. |
As you can see from the table, the more modern the car, the more it is in it. sensitive electronics. Start-Stop machines often have AGM or EFB batteries that require special charging modes, but can be lighted up in emergency start-up mode if the donor is powerful enough. Hybrid cars require special care: there can be two batteries (12V and high-voltage), and confuse them. categorically.
Alternative ways of starting and prevention
If you are in doubt or are afraid of damaging an expensive car, there are alternative solutions. The safest option is the use of launcher (booster) It is a compact lithium-polymer battery that connects directly to the terminals and allows you to start the engine without the participation of another car. The risk of voltage surges when using a quality booster is minimal.
You can also use the services of a mobile service or tow truck. Although it will take longer and cost you money, it will ensure your safety. control and calm. For owners of premium brands, free maintenance on the roads is often included, it is worth checking the insurance conditions.
Using a booster (starter) is the safest way to start for modern cars with a lot of electronics, as it eliminates the risk of overpole and jumps from the donor generator.
To avoid such situations, carry out prevention: check the density of the electrolyte (if the battery is serviced), monitor the tension of the generator belt and clean the terminals from oxidation. In severe frosts, it is recommended to remove the battery and bring it into a warm room if the car sleeps outside.
Frequently Asked Questions (FAQ)
Can I light a car with a working engine?
Technically possible, but professionals recommend to jam the donor's engine at the time of connection and disconnection of the wires, as well as at the time of start-up of the recipient. This eliminates the risk of voltage surges from the generator, which can damage the electronics. You need to start a donor only to recharge the dead battery before trying to launch.
Will the box burn if it curves when connected?
The box itself (the mechanical part) will not burn. However, a spark is a sign of current flowing, and if the sparking was strong due to an incorrect connection (overpole), the automatic transmission control unit or other devices could be affected. electronics. A single small spark when touching a mass is usually safe if the polarity is observed.
Do I need to remove the plugs when smoking?
No, modern vehicle manufacturers' instructions do not require the removal of the terminals. Conversely, the battery shutdown can result in resetting the onboard computer settings, transmission adaptations and the immobilizer. The battery in the circuit acts as a voltage stabilizer.
How long do you have to go after lighting to charge the battery?
For surface charge, sufficient for the next run, you need to drive at least 30-40 minutes in quiet mode, without traffic jams and with excess consumers off. A full charge may require several hours of driving or a stationary charger.