How to install the "Start / Stop" button with your own hands

Author: Evgeny Zhivoglyadov. Publication date: October 29, 2022. Category: Automotive equipment.

Every motorist wants to improve the comfort of using their vehicle. So, installing a “Start/Stop” button will help save you from such a routine task as turning the key in the ignition switch (IZ) to start/stop the engine again. And you will be able to save a little of your “precious time”. You can either make such a device yourself, or simply buy a ready-made kit and install it on your car. The features of installing such a device, its pros and cons, as well as some nuances that need to be remembered will be discussed in this article.

Algori

The operating principle of such an auxiliary device is quite simple:

get into the car;
depress the brake pedal;
press the “Start/Stop” button and the engine starts;
To turn off the engine, press the brake pedal again and press the button - the engine stalls.

For information! If you simply press the button without pressing the brake pedal, the engine will not start, since the +12V voltage is supplied only to additional consumers (for example, an audio complex). This is similar to turning the ignition key to the first position - ACC.

Engine starting system with a button, options for its implementation

It should be noted right away that there are quite a lot of options for connecting the button. This is due to the fact that such a system can be built taking into account a wide variety of initial conditions. As an example, below are some options for how to install such an element, possible operation algorithms of the Start-Stop Engine and the components used. Which one to choose is up to you. If the level of knowledge of electronics and circuits is high enough, you can make your own based on any of the options, you just need to understand the principle.

How the ignition key can be used:

the key is inserted into the lock, set to position I, and then, after pressing the button, the engine starts (the key allows you to remove the steering wheel lock, which is available on many cars of the VAZ family);
the key is not used at all, got into the car - pressed Start-Stop Engine, and the engine started.
What buttons can be used, their installation, connection diagram:
without locking, in this case it must be pressed and held until the engine starts;
with fixation, pressed and released, the beginning of stable operation of the motor will be detected by the electronics and the starter will be turned off.

How the ignition system works:

its start is carried out separately from starting the engine (pressing Start-Stop Engine turns on the ignition, then presses the brake or clutch again and the engine starts);
the ignition starts working simultaneously with the engine starting;
Various blocking of the Start-Stop Engine and ignition is carried out, including (the blocking scheme may involve the use of a signal from a security alarm, an open door sensor, turning on the dimensions, etc.).

These are just some of the possible options and algorithms that allow you to start the engine without a key in the car lock.

Standard delivery set

The delivery set of the universal device for equipping a vehicle with an engine start/stop button consists of:

control module;
the “Start/Stop” button itself;
built-in immobilizer scanner;
2 keychains;
installation wires;
instruction manuals (with connection diagram).

This kit is designed for installation on almost all models of both domestic and imported cars. The current price (depending on the manufacturer) is 1500÷4500 rubles.

For information! To deactivate the immobilizer, simply bring the key fob close to the scanner at a distance of 2÷5 cm. After this, a sound signal will sound, informing you that the device is ready for operation. 15÷20 seconds after stopping the engine, the control module automatically switches the device into security mode.

Starting the engine with a button, together with the brake pedal

You can take the same circuit with the rear fog lamp relay as a basis. This scheme now lacks the disadvantages of the previous one - the ability to turn on the ignition separately. The algorithm of actions is as follows:

Press the button and the ignition turns on.
We press the brake pedal simultaneously with the button - the starter turns on and starts the engine. To disable the starter, you must release the button or brake pedal.
Stopping the engine, as in the previous version, is carried out by pressing the same button on the ignition.

Regarding the connection of the brake pedal to the starter circuit. In fact, we are not connecting the pedal, but the pedal contacts, which complete the brake light circuit. This connection method has a significant drawback - if the engine stalls while driving, it can only be started by pressing the brake pedal. It's actually very inconvenient. This method is only applicable to cars with automatic transmission. For mechanics, it is best to place such contacts on the clutch pedal, since when we start the engine, we depress the clutch pedal, not the brake pedal.

Attention! If you used the brake pedal circuit, do not turn off the ignition with the pedal depressed. The fact is that pressing the pedal and the engine start button can turn on the starter, which can become damaged. Perhaps this is the only serious drawback of this scheme.

How to install it yourself

The easiest way to retrofit a car with a “Start/Stop” button is to purchase a ready-made set (fortunately, the modern market for automobile accessories is replete with such devices) and install it yourself. For any motorist who has at least some electrical installation skills and knows the pinout of the standard ignition switch block, making such an “upgrade” will not be difficult.

On a note! The connection diagrams for ready-made kits are the same from almost all manufacturers.

Work order:

dismantle the steering casing;
disconnect the ignition switch connector;

we install the control unit, button and immobilizer scanner in the most convenient places for subsequent use;
connect the wires from the control unit to the ignition switch connector in accordance with the diagram (it is supplied with the device);
lay and connect the wire to the “frog” of the brake pedal.

Important! If you purchase an ignition switch block in advance and connect the wires from the control unit to it in accordance with the diagram, then, if necessary, you can quickly return to the standard engine start/stop system using the key. If you were unable to buy a mating contact group for the 3Z (specifically for your vehicle model), then you can successfully use crimp terminal blocks of a suitable size.

Mandatory verification

We discussed above how to set up autostart for cars with a Start/Stop button. The A91 system has a Dialog mode, which will allow you to control everything that happens with the signaling. Try the following check:

The same actions are performed when starting the engine, and then the only difference appears - the smoke icon.

The results obtained in your case should not differ from those indicated above. Otherwise, it is concluded that the main unit does not control the operation of the motor or performs the control incorrectly. And then the autorun option is prohibited. There can be no other options.

In general, having a Dialog mode has many advantages. You will configure the A91 alarm as discussed in the penultimate chapter. And the display will show the value assigned to each option.

That is, you can not only change, but also view the values stored in the memory of the main unit. This is what is recommended to be done by turning on the programming mode again.

In fact, the word Dialog means more than two-way communication. The system exchanges messages with the key fob, but these messages are encrypted online. It has not yet been possible to hack any of the signals where the dialogue mode is implemented honestly. Let us assume that the statement also applies to the A91 model.

Steering wheel unlock options

When we remove the key from the lock, the steering wheel is locked, that is, fixed with a spring-loaded metal pin. In order to operate the car normally after installing the “Start/Stop” button, it is necessary to remove this function. There are two ways to do this.

The first, and from our point of view, the most preferable method:

order a duplicate ignition key;
insert it into the lock and make a mark at a level of 1÷1.5 mm above the surface level;
take out the key and saw off the “excess” in accordance with the mark;
insert the “piece” into the lock and use pliers to turn it to position 2 (now the steering wheel is unlocked);

We leave a piece of the key in the lock until the need arises to return to the standard ignition circuit.

The second way to get rid of the steering wheel lock is to completely remove the ignition switch. In the resulting hole we either mount the “Start/Stop” button or install a plastic plug of a suitable size. The main disadvantage of this method is that it will no longer be possible to quickly “return” to the standard circuit of turning the car engine on/off using a key.

Starting the engine with a key using a button

This scheme is the most elementary and its use is most common among owners of domestic cars. It has the following operating principle. Without the key, the button cannot be activated. To start the car, you need to insert the key and turn it to position 1. After that, hold down the button and hold it until the starter starts the engine. To stop the motor, you must turn the key to position 0.

To implement this, you need to purchase an ignition relay from a VAZ 2109. It has 4 contacts, two of which are high-current circuit contacts, and the other two are low-current circuit contacts. Connect one of the wires coming from the contacts of the high current circuit to pin 15 on the ignition switch, and the second to pin 30 (the first wire should be pink, and the second red). Attach the third wire (low current circuit) to the vehicle ground, and the second to the positive wire (green wire). A start button is mounted between the relay and the green wire.

You can install the button in any desired location. It is very important that it is located as conveniently as possible and at the same time prevents the engine from starting by accidental touch.

How to bypass the standard immobilizer

Many modern car models are equipped with an anti-theft device such as an immobilizer. Manufacturers equip the vehicle with a similar standard device already at the factory. The reading device is usually installed in the ignition switch, and the control mark in the key. If the security guard is not dismantled, then a key will be needed to deactivate the security mode. If you decide to remove the lock, then you need to disassemble it, find the immobilizer reader and move it to a suitable location. However, in order to start the engine with the Start/Stop button, you will still have to have the key with you.

For information! Some manufacturers, in addition to the universal “Star/Stop” kits, produce special devices for temporarily disabling (bypassing) the standard immobilizer.

Maintenance Recommendation

The current power mode is permanently stored in the memory of the power supply ECU. Therefore, if the power supply ECU is de-energized, for example, if the battery is removed, the power supply ECU will restore the power mode to the previously activated state after the battery is connected.

Therefore, if you remove the battery in any power mode other than "Off". (“OFF”), power will be supplied to the vehicle’s electrical equipment at the same moment as power is supplied to the power supply ECU (when the battery is connected). Therefore, before removing the battery, you should turn the engine start button to the “Off” mode. (“OFF”) and remove the key from the slot.

DIY option

The Internet is replete with diagrams for making your own ignition control units using the Start/Stop button. For those who like to do car tuning with their own hands, below is one of the fairly simple options that is easy to repeat:

To make this device yourself you will need:

4 relays: PTF 21.3777 (300 rubles), 231.3787 (150 rubles), 90.3747-10 (2 pieces for 75 rubles);
4 diodes (for example, 4007 - 4 rubles per piece);
button without fixation (30÷70 rubles);
installation wires of suitable diameter;
crimp terminal blocks (“female” - for switching relays among themselves, “male” - for connecting the manufactured unit to the ignition switch block).

The operating algorithm of the circuit is completely similar to the engine start/stop device of ready-made universal kits. Naturally, the homemade device does not have an additional anti-theft function (immobilizer). Otherwise, the scheme is quite workable and has been tested by many car enthusiasts.

Advantages and disadvantages

Any car tuning has both pros and cons. Among the advantages of controlling the start/stop of the engine using the “Start/Stop” button, one can note only a slight increase in comfort and minimal time savings. And here are the disadvantages (where would we be without them):

You will still have to carry the key with you. Firstly, it may be needed to simply open the car if the battery is dead and the electromagnetic door activators do not work (this is especially true at significant sub-zero temperatures). Secondly, in many modern cars the standard immobilizer mark is located in the key, so you can start the engine only if it is in close proximity to the reader.
The installation of pre-heating devices and alarm systems becomes more complicated (due to changes in the standard electrical circuit of the car).

Important! Such modernization of the car threatens to void the vehicle manufacturer’s warranty.

Table 1.31. Indicator lamp operating mode

*Cars with manual transmission. **Vehicles with M-MT multimodal manual transmission. ***If the power mode is “Off”. (“OFF”), press the clutch pedal for more than five minutes and then open the driver’s side door, the warning light on the engine start button will flash. This is not a malfunction.

Rice. 1.64. Block diagram of the electrical fixation circuit