11.11.2009
"Toolkit for Automotive Diagnostics"
Carrying out automotive Diagnostics, troubleshooting, and its further elimination is impossible without the presence of "brains".
Namely "brains", and not stolen other people's thoughts from this or that technical forum.
I won’t lie, there was time, I did a little analysis and it turned out that the average Russian city with a population of about 100 thousand people has about five “real automobile diagnosticians”. "Real" are those who "have brains, can think and think."
All the rest working in this area are “one-day diagnosticians”, “mowers”, “diagnostics - thieves of other people's thoughts” and the like.
And you don’t have to go far for examples - look around. Listen to your neighbor, his mats are replays after returning from some car service ...
For an automotive Diagnostician, “to have brains” means having and building up a set of practical methods and techniques for expedient work on identifying and eliminating a malfunction in a car.
It's long, but true.
And when these same “practical methods and techniques” are simply stolen, and thoughtlessly, without analysis and desire to continue and increase them, then we get what we get. As in the following cases...
Toyota Ipsum car.
The engine is simple: 3S-FE. The machine is old, but reliable. But each unit has its own time limit - this is what the owner of the car thought when she started throwing out a pretzel: sometimes she refused to start, she worked unstably at idle, like a “troil”, and sometimes she could stall altogether.
And do you know how many car repair shops and car services this car drove in the hope of being repaired? Very, very much. And it was not somewhere on the periphery, but in the capital of our Motherland - the city of Moscow.
Just as a fish rots from its head, so the mass character of half-educated people, "shovelers" and "diagnosticians - thieves" is concentrated in this very "capital".
As the owner of the car calculated, during the “troubleshooting” he gave all these “car services” about 100,000 rubles.
And I specifically wrote the word "Auto Service" in quotation marks, well, a normal organization cannot be called a "service", especially a "car".
A more accurate name immediately climbs into the language: “Auto-Service for painless taking of money from the population” or “Money auto-vacuum cleaner”.
Employees of such "services" do not have technical brains, there is only a desire to earn money. To lie, deceive the Client, rip off money from him and grin after him ...
The last straw in a series of unsuccessful repairs was the repair in Vladimir. There, the car began to “troit” again, then stalled, then it started up and somehow hobbled to the local “car service”.
No problem!, - the Client was assured, - we will do it quickly, reliably, with a guarantee.
And asked:
Where are you from? From Moscow? Well, then with a double guarantee.
Subtext: “What the hell are you going to drag us for 200 km” ...
How much did it cost to fix the problem? Well, absolutely "little things", quite a bit compared to previous repairs - "only" 6,000 rubles. But "with a guarantee" -☺ )
... and mats - rewinds in a long bizarre train trailed behind the car along the highway ..., -☺
He got a phone or a friend suggested - it doesn’t matter, the main thing is that the next day he ended up in the auto repair shop of Mikhail Evgenievich (his coordinates at the end of the article, nickname on the Legion-Avtodata - AVTEL forum).
Above, we touched on such a word as "methodology". And tell me, where would you start looking for such a malfunction?
Are there any trouble codes?
There is. One in memory. Common (fault area): DTC 14 (ignition signal)
Spin the starter? What for? We will turn the starter - and we will “plant” the battery, and pour fuel into the cylinders, which then goes into the crankcase and gasoline becomes “semi-gasoline”.
Why, when there is a wonderful program:
Program "58-X Generator" designed to emulate DPKV signals received from the vehicle master disk (configuration 60-2).
Opportunities:
- The DPKV signal is generated at the output of any COM port ("TXD" 3rd leg of the 9-pin COM; 5-leg "ground").
- The program allows you to change the frequency of the DPKV signal to emulate the crankshaft speed from 60 to 9000 RPM (approximately).
- Possibility to generate an additional gap of teeth to check the anti-theft function (the anti-theft function is created by the CombiLoader from SMS-Software).
Developer: Alexey Mikheenkov (C) SMS Software
The program on the Internet is distributed free of charge.
Here is her appearance:
And here is how it connects and emulates:
A spark gap is placed on the ignition coils, the nozzles are turned off, the program starts and the “quality and presence of a spark” looks. Convenient: the engine does not work, the battery is not discharged by dozens of starts, “look for a malfunction as much as you like ...
But the spark was amazing!
So what's the deal?
Many manuals and reference books describe such a troubleshooting method as "moving harnesses, connectors and loops."
Moved. First in one place, then in another. And found.
That is, he first determined the “fault area”, and then he began to narrow it down and reached the true cause, here it is, in the bottom photo:
 |
 |
 |
 |
Guess what is the reason? The error is a simple one. But in Moscow, it turns out that finding it and, like, “eliminating” it costs about 100,000 rubles ... However, probably not only in Moscow?
Once the engine was dismantled, and when they began to assemble, they screwed the "mass" of the ignition coils badly. Type "acquired". Over time, she loosened up and ... "we have what we have."
The client has left. Thanks. I was surprised. And he promised to go to Vladimir "to figure it out."
And the next day the client called again.
No, not from yesterday's malfunction. Here the “improbability theory” has already played a role - a new malfunction, another one: a light on the instrument panel came on, signaling a malfunction of the generator.
Well, a generator is a generator.
And even gives a charge of about 14 volts.
However, the malfunction is still present, as the fuse in the fuse box constantly burns out (photo on the right).
You don't need to invent anything. For troubleshooting in the electrical circuits of a car, many devices have long been invented, for example:
A device for finding faults in the electrical circuits of a car
Set FF310 designed to detect and localize breaks and short circuits in vehicle electrical circuits. Included in the kit FF310 includes miniature transmitter and receiver. The transmitter is connected to a faulty electrical circuit and generates a high frequency signal. A flexible probe receiver is used to locate breaks or short circuits. This is achieved by moving the probe along the wire harness. The receiver identifies the type of malfunction (open or short circuit), which is indicated by light and sound indicators. The versatility of the design allows the device to be used on any cars and motorcycles with on-board voltage from 6 to 24 Volts. Without any restrictions, the device can also be used on promising vehicles with an on-board network voltage of 42 Volts.
The set is supplied in a convenient plastic case, which, in addition to the items mentioned above, also includes a special piercing probe and a set of connectors for connecting the transmitter to fuse sockets of various types.
Have you read? This is the device that was used. What, it turned out, look at the photo on the right: this is the so-called "burnout". Hence the fuse "flyed" constantly. And the light on the instrument panel was on, signaling a malfunction. Troubleshooting took a little time.
What is the outcome?
Both the first and second malfunctions were from the category of “not very complex”.
And they could be found without the use of these "adapt"?
It could be.
But let's consider the time factor.
Using certain "tools" AutoDiagnost can significantly reduce the time for troubleshooting and troubleshooting.
And time, as you know, is money.
And now you can try to summarize everything by the title of the article:
"Tools for Autodiagnostics". So what is required for this:
1. Man + Light Soul. All other colors are not suitable for those who have chosen the profession of AUTOMOBILE DIAGNOSTICS as their profession.
2. The ability to analyze situations, structure your accumulated experience and fuse the experience of colleagues into it
3. Internet: 10 years ago it was still in its infancy, now it is starting to grow, and in 10 years it will be impossible for a car diagnostician to work without it
4. Critical self-assessment: always remember that the time of Geniuses has passed and nothing can be discovered in AutoDiagnosis, you can only skillfully use the proposed technical and theoretical tools
But that's not all.
It is impossible to list "everything".
Can add. Add to the topic where this material is being discussed.
Surely every automotive diagnostician will have something of their own ...
I dealt with the malfunctions in this article
Kudryavtsev Mikhail Evgenievich
Discussion on our forum:
Information on car maintenance and repair can be found in the book (books):
For people who often deal with engines, this device is very useful. It is very simple in design and use. With this device, you can check the windings of transformers, chokes, electric motors, relays, magnetic starters, contactors and other inductance coils from 200 μH to 2 H. It is possible to determine not only the integrity of the winding, but also the presence of an interturn short circuit in it. The figure shows a diagram of the device:
(click on image to enlarge)
The basis of the device is a measuring generator on transistors VT1, VT2. Its operating frequency is determined by the parameters of the oscillatory circuit formed by the capacitor C1 and the inductor under test, to the terminals of which XP1 and XP2 probes are connected. The variable resistor R1 sets the required depth of positive feedback, which ensures reliable operation of the generator.
Transistor VT3, operating in diode mode, creates the necessary shift in the voltage level between the emitter of transistor VT2 and base VT4.
A pulse generator is assembled on transistors VT4, VT5, which, together with a power amplifier on a transistor VT6, ensures the operation of the HL1 LED in one of three modes: no glow, blinking and continuous burning. The operating mode of the pulse generator is determined by the bias voltage based on the transistor VT4.
The device works as follows. When the probes XP1 and XP2 are closed, the measuring generator is not excited, the transistor VT2 is open. The constant voltage at its emitter, which means that based on the VT4 transistor, is not enough to start the pulse generator. Transistors VT5, VT6 are open at the same time, and the diode burns continuously, signaling the integrity of the circuit under test.
When a working inductor is connected to the probes of the device, say, the motor winding and the engine of the variable resistor R1 is set to a certain position, the measuring generator is excited. The voltage at the emitter of the transistor VT2 increases, which leads to an increase in the bias voltage at the base of the transistor VT4 and the start of the pulse generator. The diode starts flashing.
If there are short-circuited turns in the winding under test, the measuring generator is not excited and the probe works, as with closed probes (the diode just glows).
When the probes are open or the circuit of the coil under test is open, the transistor VT2 is closed. The voltage at its emitter, and hence at the base of the VT4 transistor, increases sharply. This transistor opens to saturation, and the oscillations of the pulse generator break down. Transistors VT5, VT6 are closed, the diode HL1 is off.
In addition to those indicated in the diagram, transistors VT1-VT3 can be KT315G, KT358V, KT312V. KT361B transistors can be replaced with any of the KT502, KT361 series. Transistor VT6 is advisable to use the KT315, KT503 series with any letter index. Permanent resistors - MLT-0.125; capacitor C1 - KM; C2 and SZ - K50-6; LED AL310A, AL 307A, AL307B, you need to connect a resistor with a resistance of 68 ohms in series in the circuit .; power supply - 3V (regular batteries or krone).
It may happen that in the extreme right position of the resistor slider and with the probe probes open, the diode will glow. Then you have to pick up the resistor R3 (increase its resistance) so that the diode goes out.
When checking coils of small inductance, the sharpness of the “tuning” of a variable resistor may turn out to be excessive. It is not difficult to get out of the situation by connecting in series with the resistor R1 another variable resistor with low resistance, or using a resistance store instead of a variable resistor or a set of resistors connected by a small-sized multi-position switch (roughly, smoothly). The information is taken from the magazine "Radio" No. 7 for 1990.
And this is how I made it:
Anyone interested, write, there is a seal in the Sprint-Layout format
In the video, I demonstrated it in operation, obviously took a non-working engine.
One of the common causes of problems with electrical appliances is damage to the cable in a certain section of the wiring. It is good when the location of the cable break is known and available for quick repair. But what if a break or short circuit occurred in a closed section of the circuit, somewhere in the strobes? In this case, you must either call a professional electrician to troubleshoot, or independently look for a break. And if you decide to read this article, then you probably chose the second option.
Short circuit in hidden wiring
We are looking for areas of closure
Before searching for a break in hidden wiring, it is worth making sure that there is voltage at the input, and that the machines are working. If, upon inspection of the machines, it was determined that the plugs were in the cocked state, then the emergency occurred in the house itself, but if the machine is in the off position, then this indicates a short circuit. Then you can proceed to the direct search for the site where the failure occurred.
As a rule, the wiring in the house is installed according to the ray principle. In other words, rays (wiring) diverge from the dose box to the sockets, and a separate cable is connected to each switch. We recommend that you familiarize yourself with the wiring diagram that is installed in your home - this will greatly simplify the search for a break or short circuit in the circuit.
Find the dosage box and open it - there are several rolls inside. On each line, it is recommended to measure the resistance and voltage. If the indicators are positive everywhere, it is necessary to look for the cause in another dose box. As soon as you find a twist on which there is no voltage and resistance, this means that a break has occurred on this line, which must be eliminated.
We are looking for sections of the circuit in hidden wiring
So, we have determined the general area where the gap occurred. Now it is necessary to find out in which particular place the gap occurred, and then eliminate it. Consider how to find a break in hidden wiring.
Finding a break point
The first, and most simple, method of further action is to open the plaster and find a wire on which there is no voltage. The opening is made from the junction box and further to the place of damage. A large open section of the strobe on the wall, dust and noise - all this in order to find and eliminate a section of several centimeters in size.
Note that in some cases it is even difficult to determine the route of the cable that runs through the wall. It’s good if electricians used GOSTs and wiring rules when laying the cable, but there are frequent cases when cables are laid in the shortest way to reduce costs. In this case, it may be necessary to remove all plaster from the wall in order to determine the route and eliminate the defect. In order to avoid such a destructive repair, electricians use a special device to detect a broken hidden wiring.
Professionals most often use the MS-58M device - a special non-contact probe for determining the voltage on the track through various materials, incl. concrete, brick, wood, etc.
Instrument MS-58M
For everyday purposes, simple variations of the combined type, like the MS-48NS, are also used. Using this device, you can determine the voltage on a certain section of the conductor, ring the wire, and also determine the section of the route on which the voltage disappears.
Instrument MS-48NS
As a rule, such devices accurately determine the location of the break - up to 8-12 cm. Thus, the amount of work is significantly reduced and the cable can be repaired without significant damage.