Cars whose system is based on an injector have a special line that transmits data to. They call it K-line, and if you have a special adapter, you can connect your laptop to this “line”. Then, with the help of simple manipulations, you can update the software of the car’s electronic systems with your own hands, diagnose their performance, or install different firmware on the car’s ECU.
With the help of such an adapter you can carry out independent diagnostics of your car.
The K-line adapter is used to transfer data from the ECU to the user's PC. Information passes through a separate line; moreover, the inputs for receiving information and sending it can be fundamentally different! To coordinate them, they use a K-line adapter. The K-line adapter is not very expensive, despite this, many car enthusiasts try to make it themselves.
On the World Wide Web you can find many diagrams of homemade K-line adapters. There are also the simplest devices that are designed to work on COM, but this port no longer exists on modern computing devices. It is much more convenient to use an adapter that converts to USB, but the technical component of such a device is much more complicated.
If you decide to make such a means of transmitting data from electronic to PC with your own hands, then you should make it with an output to a USB port. To do this, you will have to get hold of a couple of microcircuits, a printed circuit board and many additional parts. In fact, everything can be implemented much more simply; it is enough to have a cable from an old phone that is collecting dust somewhere in a desk drawer.
Let's make a list of all the elements that we need to create a K-line adapter:
It is not necessary to assemble the circuit with your own hands according to this layout; you can do it in the way that is convenient for you. If you wish, you can create a printed circuit board, but this particular k-line adapter was made by surface mounting.
You can borrow two transistors from a computer power unit if you have an unnecessary one, or purchase them at a radio parts store. There, buy any rectifier diode that has a low parameter. You don't have to solder it in if you don't mix up the poles during use, but for safety it's worth incorporating it into the circuit. We must use a capacitor to eliminate interference on the line.
So, as soon as the circuit is assembled, we start working with the USB cable. You need to install a special driver on your computer that allows the data transmission system to operate at different speeds, it is called PL-2303. Once installed, connect the USB cable and check its functionality. If you found it in the device manager, then it is working.
Be sure to remember which COM port number it appears in the system, or better yet, write it down. Now download the program to check if the port is working. You can use B&B's COM Test.
Let's move on to upgrading the k-line cable with our own hands. We unsolder the cable connector that connected to the phone, after that we need to understand what each of the wires is intended for. To determine this, connect the cable to the PC, launch the already downloaded program, select the COM port of our cable, set the speed to any.
The black wire is a minus; you can check this by first ringing it on the USB connector housing. Using a voltmeter we find a wire whose voltage is 3.3 volts. Now try to write some command in the program window, if during this process the voltage on the wire changes, then it is an output, i.e. TxD.
Now let’s try , which is the input; under no circumstances connect it to the previously discovered “minus”. If you connect it to the desired wire, the text you write will be displayed in the second window of the program. This means that you not only transmitted the data, but also received it.
Now we solder these wires into our circuit and attach them to the OBDII connector with our own hands. After this, carefully look to see if there are any breaks or short circuits; they need to be eliminated. Moreover, if desired, give the device reliability by securing it in some kind of case.
If you want to implement this, simply solder a diode into the circuit in conjunction with a transistor rated more than 500 Ohms so that it does not smear the signal on the line.
Now we connect the same cable to our PC, additionally supplying 12 volts to the circuit. If the information is duplicated, then everything is working properly. Now you can connect to the computer’s electronic unit and carry out diagnostics.
To summarize, it should be said that making a k-line adapter with your own hands is not difficult; you only need basic knowledge of circuit design and the ability to work with a soldering iron. By making such a device yourself, you can take into account the technical components individually for your car and save one or two thousand rubles.
This device is designed to connect the car interface with the computer interface and convert streaming signals that go along the K- and L-lines. You can purchase this device at any auto parts store for a fairly reasonable price. In the event that it is possible to do it yourself, first of all you need to purchase components and have a reliable information base.
Operation of an electronic device significantly reduces the risk of possible damage to car systems and promptly informs the driver about this. In this article we will talk about using the K-Line adapter, as well as how to make it yourself.
The K-L-Line adapter is used for diagnostic work and determining the operating parameters of engines on foreign-made cars, as well as domestic cars that are equipped with electronic control units for engine systems.
After connecting the adapter and launching the corresponding program on the computer, you can perform the following diagnostic operations:
You can also control and monitor systems while driving:
Diagnosis with a K-line adapter is only possible with special software that matches the car brand.
Diagnostic measures on domestic cars of the GAZ and VAZ brands are often carried out using the Open Diag program (1.3.9). It is the latest version, perfect for VAZ, UAZ, GAZ car models.
Also, for diagnosing VAZ models, the Motor-Tester and Diagnostic Tool v 1.3.1 programs are used.
Engines equipped with an electronic fuel injection control system with IKAS-5.4 control and their modifications, usually GAZ and UAZ, are diagnosed with an adapter using GAZ-DIAGN software.
Imported cars are checked using various diagnostic programs that correspond to the given manufacturer. As a rule, they are rarely interchangeable due to the design features of engine systems. So, Chevrolet Explorer v 1.6 is perfect for Chevrolet cars. Using this adapter, you can read information about the status and operation of engine systems, automatic transmission, and chassis. This software has various modifications and can work on many Chevrolet models.
Cars from the Daewoo manufacturer are diagnosed using the Research Daewoo program and its modifications.
There are many different programs for computer diagnostics of vehicle systems. In turn, these contribute to the correct conduct of diagnostic operations. Another important aspect is what vehicle they are used on. It is in these basic parameters that programs differ from each other.
The Motor-Tester software, VAG-Tool, Com K-Line VAG adapter and Uniscan have different characteristics, a unique interface and are designed to work with certain brands of cars.
Cars manufactured by VAG (Volkswagen, Seat, Audi, Skoda, among others) with an electronic fuel injection system work with the VAG Com program. The K-line adapter reads and processes information from all engine components, which allows timely prevention and elimination of various problems.
The diagnostic tool "Motor-Tester" is widely used for diagnostic operations of domestic transport systems.
It is not whimsical and can be used in almost various conditions. Through software, it takes readings from the electronic control unit. At the same time, it is possible to save the indicators that the tool visualizes both in digital equivalent and in graphical form.
Uniscan is a program that has proven itself to be more versatile. Its use is possible on cars manufactured in the United States, Asia and Europe with a production year up to 2001 inclusive. By downloading this program to your computer, you can easily carry out diagnostic operations on machine systems and accurately determine the cause of a malfunction of a particular part.
This tool can also be made by hand. The Com circuit is simpler, but due to the lack of this connector on laptops, it is less practical and therefore unpopular.
As for circuits with USB connectivity, the situation is different. They are more practical, but have a complex design. To facilitate this task, craftsmen began to use data cables from unusable mobile phones.
For work we will need the following tools and materials:
The process of assembling a circuit can be carried out in three ways: using a breadboard, using a printed circuit board, and using the surface-mounting method. In this review we will talk about how to make a K-Line adapter with your own hands using a surface-mounted installation, according to a schematic diagram, using a cable from a mobile phone. In a radio parts store or in an old computer unit, you can find transistors VT1 and VT2, as well as other radio components.
We use diode VD1, it is important that it has a low voltage drop. To protect against interference, it is important to install capacitor C1 on the adapter.
After the circuit is assembled, you should move on to the data cable.
First, we load the driver for the K-Line adapter PL2303 with the ability to support non-standard speed. After the driver is installed, you need to connect the cable and make sure it is working. It will appear in Device Manager on your computer display. Next, you need to remember what value it is attached to. To test the port, you must install the B&B Com Test program.
The next operation concerns the conversion and connection of the data cable. To do this, you need to disassemble the plug on the phone side and unsolder it. Determine the functionality of the wires. To do this, connect the cable to the computer and launch the program. Next, select the appropriate one. As a rule, the black wire of the cable corresponds to a negative value and should be connected to the body of the USB plug. Then, using a voltmeter, you need to find a wire whose value will correspond to 3.3 volts. When measuring the voltage on it, you need to write something in the corresponding program window. If the voltage readings change, this means the cord matches the TxD pin.
Then we connect it to the two remaining ones, and when connected to the correct wire in the program window, the previously entered information will be copied. This is the output of RxD. After the values are set, they should be soldered according to the diagram.
Before turning on the K-Line adapter, it is important to make sure that the device is installed correctly and that there are no short circuits in the circuit or wires.
You can check the functionality of the device as follows.
We connect the adapter to the computer port (after powering it with 12 W) and check it using the same program. If the information entered in the upper window is duplicated, then the device is working and can be connected to the vehicle’s electronic control unit.
The K-line adapter is used not only as a method for additional diagnostics of machine systems, but also for flashing the firmware of the power unit control unit. On certain brands, the firmware is carried out via a diagnostic plug, while on others it is necessary to dismantle the engine control unit itself and upgrade it. The original version of Gionix is supplied as a standard firmware program, which has proven itself well on Euro-4 generation Lanos cars.
So, we found out what the K-line adapter is used for and how to make it yourself. As you can see, this is a very useful device for every motorist.
The adapter we bring to your attention, despite its apparent complexity, is simple to manufacture and will delight you with impeccable operation without problems and without failures. This option (assemblies from Shuriken) has been working for me in the most difficult combat conditions for more than 3 years. This scheme can be strongly recommended for repetition if intensive professional use is planned.
To enlarge the diagram, click on the smaller copy.
Several KL-Line schemes (c) Oleg Bratkov
This diagram was provided for publication by Oleg Bratkov from Pyatigorsk. A special feature of the circuit is the exclusion of the rather “delicate” MC33199 microcircuit and the use of L9637 (or analogues) used in VAZ APS4/6 immobilizers. And another development by Oleg, based on “advanced” DS275 and L9637 microcircuits. It is easy to see that with a slight movement this circuit can be turned into a K-Line.
Adapter for MAX232 and 74HST14
The next optically isolated K-L-Line adapter from Oleg Bratkov is intended more for “gourmets”. Below is the author's text.
The left side is connected to the car, powered by 12 volts from the on-board 12 volt network. The right side is connected to the COM port respectively. 12 volt power can be taken from a 220/12 volt power supply. I placed the adapter inside the system unit, powered by 12 volts from the computer's power supply. The connector was brought out to the front panel onto a plug for a 3.5-inch drive. The setup is simple. Using an oscilloscope, we look at the signal at the collector of the optocoupler transistor. If it is blocked, the leading edge of the pulses will be delayed - it is necessary to increase the current through the optocoupler LED, that is, reduce the resistance of the limiting resistor. For 4N25 you need about 10 mA. If the trailing edge is blocked, reduce the resistance of the collector pull-up resistor. I succeeded at the indicated denominations. A 500 kOhm - 1 Mohm shunt resistor is placed between the base and emitter of the 4N25 optocoupler transistor.
KL-Line©Sneg
This KL-line adapter is essentially composed of two circuits. The first is the K-line channel, completely repeats the design of the KR-2 adapter NPP NTS of the first releases, for connecting to the ECU of all domestic cars, including January 4 and GM (without a switch). Another diagram was taken from http://orlovdv.narod.ru/COMport.html, developed as a KL-line scheme. In the NPP NTS circuit, there is no line L, which is necessary for diagnosing some foreign cars; in the second circuit, for connection to the GM and January 4 units, it is necessary to change the pull-up resistor. This circuit also provides L-line protection against short circuits. Another advantage of this design is that it does not use the MC33199 chip, which only exists in a planar package.
When installing the adapter, it is highly advisable to use foreign-made components.
ATTENTION!!! When using analogues of the MMBF170 transistor, failures may occur when programming Mikas 7.1 controllers.
K-L-Line adapter. A simple transistor circuit.©MOBIL
This diagram was provided for publication Yuri (aka "mobil") from Izhevsk. A simple transistor adapter. It does not have the disadvantages that occur in other simple transistor circuits. The peculiarity is that the front along which RS-232 synchronization occurs does not delay. As a result, the adapter confidently works with diagnostic programs at speeds up to 115 kBaud. Does not require negative feed, since the transistor “pulls” the input of the COM port to +12, and does not bypass the pull-up resistor. Works reliably with a 5 meter long cable.
It is advisable to place resistors installed next to the RS-232 connector directly in the connector body. This eliminates interference and protects the COM port of the computer. Tested on VAZ, GAZ, VW, AUDI using several computers.
Had a car Nissan Almera №16. Everything was fine, but one day, returning home from work, I noticed that the smoothness of the ride was gone, there were jumps in rpm within 1000, trips to the diagnosticians did not yield any results (everyone, without exception, could not get into the ecu) so many forums and literature on diagnostics were searched Almer, as it turned out, not all programs and adapters are able to see Alma’s brain, she has an obdII connector, but the protocol through which she transmits and receives information is not like most cars, both Russian and foreign auto industry. And after much searching, a project for a k-line adapter for diagnostics was found. It was possible to buy a ready-made version from a master kit that costs 1200 rubles, but I had experience in soldering SMD components and I myself like to assemble something and bring it to life.Schematic diagram of the K-Line adapter
Device Parts List
Chips:
FT232RL – 1 pc.L9637D – 1 pc.SMD resistors (size 0805)Denominations on the case:270 – 2pcs511 – 1 piece271 – 2 piecesTantalum capacitors SMD (size 0805)475C106C100nf10uF 10voltRegular diode 1N4148LEDs 2 pieces SMD, which color do you like best).3-pin connector for soldering to the board.Mini usb connectorWell, a mini usb - usb cord
Thanks to this device, I was able to find two errors and successfully correct them. Everything worked like a new car, the spark plugs again became brownish-brown around the rim and the white clean electrode insulator, instead of black and this and that. Smooth revolutions appeared from idle 700 to 1000 with slow throttle application. I am very pleased with the result. Diagnostics and repair cost me 140 rubles. - (per chip) the remaining components were soldered from various car radio boards, power supplies, etc.So if you have a Nissan Almera, I think this manual will come in handy. Why spend money on traveling to diagnosticians when you can assemble it yourself and do diagnostics at any time, anywhere. As the saying goes, The devil is not as scary as he is painted!
