Winter, a low battery and an urgent need to start the car - the situation is familiar to many car owners. But when it comes to lighting a car with automatic transmission (automatic transmission) from another car, also with an automatic transmission, a lot of questions and doubts arise. Is it possible to do this at all? Will the procedure damage the electronics or transmission? Why are some drivers categorically against it, while others calmly practice this method?

In this article we will figure out why lighting two cars with automatic transmission requires a special approach, how it differs from a similar procedure with manual transmissions, and how to minimize the risks for both cars. We will analyze technical aspects, refute common myths and provide step-by-step instructions taking into account the specifics of automatic transmissions. We will pay special attention to modern cars with sensitive electronics and hybrid systems.

Why lighting an automatic transmission is controversial: technical reasons

The main problem lies in the design features of automatic transmissions. Unlike mechanical transmission, where the clutch physically separates the engine and wheels, in an automatic transmission the connection is made through torque converter and a complex system of planetary gears. When starting the engine "from the pusher" or when lighting a cigarette, the following risks arise:

  • 🔋 Power surges - modern automatic transmissions are controlled by electronic units (ECU), which are extremely sensitive to current changes. Incorrect wiring connections may cause the transmission computer to malfunction.
  • ⚙️ Load on torque converter — when starting the engine from a donor, the oil in the automatic transmission does not have time to warm up, which increases wear on the friction discs.
  • 📶 Problems with the CAN bus - in machines with multiplex wiring (for example, Volkswagen MQB, Toyota TNGA) A power surge can cause errors in several systems at the same time.

In addition, in vehicles with start-stop system (for example, BMW EfficientDynamics, Mercedes Eco Start/Stop) lighting a cigarette may disrupt the settings of the battery sensor (IBS or BMS), which will lead to incorrect battery charging in the future. Manufacturers of some models (for example, Audi with boxes S-Tronic) directly prohibit lighting in the operating instructions.

📊 How often do you encounter a dead battery?
Never
1-2 times a year
More than 3 times a year
Constantly in winter

Myths about lighting cars with automatic transmission: what is true and what is not

The driving community is full of conflicting statements about lighting automatics. Let's look at the most common ones:

Myth Reality Explanation
"Lighting up kills the automatic transmission" ❌ Not really The very fact of lighting does not harm the box, but incorrect execution (for example, trying to start a car with a dead battery in neutral without warming up the oil) can accelerate wear.
"You can only light a cigarette using a manual" ❌ No Technically there is no difference, but donor machine must have a working battery and generator. The main thing is to observe the polarity and sequence of connections.
"Modern cars cannot be lit" ⚠️ Partially true Car with system Start-Stop (for example, Ford EcoBoost, Hyundai Smartstream) require use boosters instead of traditional lighting.
"It is imperative to silence the donor" ✅ Yes, but with nuances For cars until 2010 this rule is relevant. In modern cars (for example, Skoda MQB) you don’t have to jam it, but you need to turn off the ignition and all energy consumers.

You need to be especially careful with premium cars (Mercedes-Benz, Lexus, Volvo), where electronic transmission control systems are closely integrated with other units. For example, in Lexus RX with box Direct Shift-8AT lighting a cigarette while the donor is working may cause an error P0700 (transmission malfunction).

⚠️ Attention: If your vehicle is equipped with Idling Stop (automatic engine stop at traffic lights), lighting a cigarette can disrupt the settings of the battery sensor. In this case, after the procedure, a reset via the diagnostic scanner is required (for example, Launch X431 or Autel MaxiCOM).

Step-by-step instructions: how to properly light a machine from a machine gun

If you decide to light a car with an automatic transmission from another car with an automatic transmission, follow this algorithm. It takes into account the characteristics of modern vehicles with sensitive electronics.

Turn off both vehicles and remove the keys from the ignition.

Make sure the batteries are the same voltage (12V or 24V)

Check the integrity of the cigarette lighter wires (cross-section at least 16 mm²)

Turn off all power consumers (headlights, heater, radio) in both cars-->

  1. Connecting wires:

    • 🔴 Red wire: "+ donor" → "+ recipient"
    • ⚫ Black wire: "− donor" → metal part of the recipient motor (NOT on the negative terminal!)

This will help avoid sparking when connecting the last wire.

  • Starting a donor: Start the donor car and let it run for 5-7 minutes at ~1500 rpm. This will allow the generator to recharge both batteries.

  • Attempt to start recipient: Turn the key to position ON (without starting the starter) for 30 seconds - this will allow the electronics to initialize. Then try to start the engine. If it doesn't work the first time, wait 2-3 minutes before trying again.

  • Disconnecting wires: Remove the wires in negative sequencewithout stopping the recipient's engine. Let it run for at least 15 minutes to charge the battery.

    • For vehicles with Start-Stop (for example, Peugeot e-THP, Citroën PureTech) it is recommended to use starter charger instead of lighting a cigarette. These systems require a stable voltage of 13.8-14.4V, which is difficult to provide from another car.

    💡

    If, after lighting a cigarette, the icon lights up on the dashboard Automatic transmission (such as "AT Temp" or "Check Transmission"), don't panic. In 80% of cases, the error is reset after 2-3 engine starting cycles. If the indicator does not disappear, diagnostics with a scanner is required (codes P0715, P0730 or P0841 often appear after power surges).

    Which cars with automatic transmission cannot be lit: black list

    Some models are strictly not recommended to be lit in the traditional way due to the characteristics of the electronics or transmission. Here is a list of cars where the procedure can cause serious problems:

    • 🚗 BMW with boxes ZF 8HP (for example, BMW 5 Series G30, X5 G05) - sensitive to voltage surges, transmission adaptations can be reset.
    • 🚗 Mercedes-Benz with 9G-Tronic (for example, E-Class W213, S-Class W222) - require the use of only original boosters Mercedes-Benz Starter Battery Booster.
    • 🚗 Land Rover/Jaguar with boxes ZF 9HP — errors in the system are possible Terrain Response after lighting.
    • 🚗 Toyota/Lexus with hybrid systems (Prius, RX 450h) - a high-voltage battery requires special equipment.
    • 🚗 Volvo with systems Pilot Assist — it is possible to reset the calibration of cameras and radars.

    For these vehicles, manufacturers recommend using portable jump starters (for example, NOCO Boost Plus, Carku E-Power Elite) with surge protection function. The cost of such devices starts from 5,000 rubles, but they are guaranteed not to damage electronics.

    ⚠️ Attention: If your vehicle is equipped with Keyless Go (keyless entry), lighting a cigarette may cause an immobilizer error. In this case, you will need to retrain the keys through the diagnostic connector (the procedure costs ~2000 rubles in service). Especially relevant for Audi Q7, Porsche Cayenne and Bentley Bentayga.

    Alternative ways to start a car with automatic transmission

    If traditional lighting is not possible or is risky, consider alternative methods:

    1. Starting device (booster):

      Portable lithium polymer boosters (e.g. Berkut Smart Power, AVS Energy Box) allow you to start the engine without connecting to another car. The main advantage is stable voltage without surges. Suitable for cars with engine capacity up to 3.0 liters.

    2. Push start (only for some automatic transmissions!):

      Which automatic transmissions can be started using a pushrod?

      Only old-style boxes with a torque converter (for example, Aisin Warner A340E, GM 4L60-E). Modern adaptive boxes (ZF 8HP, Mercedes 7G-Tronic) when launched in this way they fail.

      The method is extremely risky and is only suitable for cars before 2005 release with simple 4-speed automatic transmission. To do this:

      1. Make sure the selector is in position N.
      2. Accelerate the car to a speed of 30-40 km/h.
      3. Move the selector to position D and immediately press the gas.

    3. Removable battery:

      If you have access to a charged battery (for example, from another car), you can temporarily connect it to replace the discharged one. The main thing is to observe polarity and not touch the terminals with metal objects.

    For owners of cars with the system Start-Stop (for example, Ford Focus 1.0 EcoBoost, Opel Astra 1.4 Turbo) the only safe option is to use original charger (for example, CTEK MXS 5.0), which restores the battery in a gentle manner.

    💡

    If your vehicle is equipped with AGM or EFB batteries (for example, Varta Silver Dynamic AGM, Bosch S6 EFB), never use cheap Chinese boosters. They do not provide the required current and can damage the battery.

    What to do after successful lighting: checking systems

    Even if the engine starts, this does not mean that all problems are solved. After lighting, you must perform several mandatory checks:

    • 🔋 Voltage check: When the engine is running, the voltage at the battery terminals should be 13.8–14.4V. If the indicator is lower 13.5V, the generator is faulty.
    • ⚙️ Automatic transmission diagnostics: Ride 5–10 km, paying attention to the smoothness of the shifts. Jerks or delays may indicate a failure of adaptations.
    • 📊 Reset errors: If the indicators on the dashboard are on ESP, ABS or Check Engine, connect the diagnostic scanner and clear the errors. Popular codes after lighting: P0562 (low voltage), U0100 (loss of communication with ECM).
    • 🔧 Electronics check: Make sure all systems are working: climate control, multimedia, parking sensors. In some cases a reboot may be required (soft reset) by disconnecting the battery for 10 minutes.

    For vehicles with adaptive gearboxes (e.g. DSG, PDK, ZF 8HP) after lighting it is recommended to perform reset adaptations through diagnostic equipment. This takes 10–15 minutes and costs ~1000 rubles in service, but prevents jerking when changing gears.

    If, after lighting a cigarette, you notice that the car accelerates worse or there are jolts when changing gears, this may indicate reset automatic transmission adaptations. In this case you need:

    1. Drive 50–100 km in manual mode (if there is such a function), using all gears in turn.
    2. Avoid sudden acceleration and braking for the first 2-3 days.
    3. If the problem persists, contact service for forced adaptation through a scanner.

    FAQ: Frequently asked questions about lighting cars with automatic transmission

    ❓ Is it possible to light a diesel machine from a gasoline machine?

    Yes, but with reservations. Diesel engines require more starting current, so the donor battery must be in excellent condition (capacity of at least 70 Ah, cold cranking current - from 600 A). For diesel engines with a volume of more than 2.5 liters (for example, BMW 3.0d, Mercedes OM642) it is better to use a booster.

    ❓ Why doesn’t the box work after lighting a cigarette?

    Most likely reasons:

    1. A power surge damaged the automatic transmission control unit (TCU).
    2. Transmission adaptations have gone wrong (learning via scanner is required).
    3. There is not enough oil left in the torque converter due to a cold start.

    In the first two cases, diagnostics will help, in the third - warming up the oil to operating temperature (drive 10-15 km without sudden acceleration).

    ❓ Is it possible to light a car with a variator (CVT)?

    Technically possible, but CVTs (for example, Nissan Xtronic, Toyota Direct Shift-CVT) are even more sensitive to voltage surges than classic automatic transmissions. Recommendations:

    • Use only high-quality wires with a cross-section of at least 20 mm².
    • Avoid sparking when connecting.
    • After starting, let the variator warm up for 5–10 minutes at idle speed.

    If a hum or vibration appears after lighting the cigarette, this is a sign of damage to the variator belt. Contact service immediately!

    ❓ How often can you light a car with an automatic transmission?

    Frequent lighting (more than once a month) indicates problems with the battery or generator. This is especially dangerous for automatic transmissions, since each voltage surge increases the risk of electronic failure. If you regularly experience battery drain:

    • Check the leakage current (norm: up to 50 mA).
    • Make sure the generator is delivering 13.8–14.4V at idle speed.
    • For vehicles with Start-Stop use AGM batteries (eg Varta Start-Stop Plus).
    ❓ What to do if after lighting a cigarette the car starts, but immediately stalls?

    This is a typical situation where the battery is so discharged that it cannot keep the engine running. Proceed like this:

    1. Do not turn off the engine and let it run for 15–20 minutes at ~1500 rpm.
    2. If the engine stalls repeatedly, the problem is in the generator or severe sulfation of the battery.
    3. For a temporary solution, you can connect the booster in parallel with the battery (but not instead of it!).

    If after 30 minutes of operation the engine still stalls when you try to start, the battery most likely needs to be replaced.