The car, as you know, refers to vehicles, but not to luxury goods. That's just the cost of some diagnostic and repair operations makes one doubt this. In many respects, this also applies to Japanese cars that are popular with us.
So knowing how Toyota’s self-diagnosis is launched, for example, can save you a lot of money. There is nothing particularly complicated in this operation, you just need to be more careful and follow the instructions exactly. So how to do a self-test? “Toyota” is a fairly new car (it is assumed that you do not have a rarity), and therefore there are a lot of electronic circuits in it, which greatly facilitate this task.
Basic information
In principle, any more or less modern car has a special engine self-diagnosis unit. How does this mechanism work? Pretty simple: electronics constantly monitors the performance of devices, comparing them with those reference values that were laid down by the manufacturer. If something is not right, a diagnostic program is turned on, which specifically determines what exactly failed. Roughly speaking, this is how Toyota self-diagnosis works.
Only when all the elements are in order, the bypass program will be removed, and the engine will begin to work in normal mode. Note that many are familiar with the luminous inscription "CHECK" or a separate icon with an image of the engine, which signal a malfunction. If the breakdown has been repaired, the image or icon goes out.
In general, this is self-diagnosis. Toyota in this regard is a very "friendly" car, since everything is immediately visible on the dashboard (in most cases), and the Japanese themselves took care of the presence of normal, detailed manuals and recommendations that describe all possible error codes, which greatly facilitates the life of service workers and ordinary motorists.
How useful is this operation?
It is important to remember that data about the error that occurred must be entered into the memory of the on-board computer. If its power supply was not interrupted (the battery was not removed, for example), this data can be read from the instrument panel (Toyota) or pulled out of the computer (Nissan). In case of some malfunctions, the engine will immediately stall, but in some cases, when the malfunction allows the operation of the machine, the error code is simply written to the internal memory of the computer.
This is very convenient, since later it will be possible to find out the ins and outs about the state of your car. Actually, this is a good self-diagnosis. Toyota, therefore, compares favorably with other foreign cars in that you can save a lot on figuring out the reasons why various problems occur.
In addition, this way you can find out the reasons why the machine from time to time behaves abnormally. For example, you stopped due to a stalled engine in the middle of the road. Turned a couple of times the key in the ignition switch - the engine started quietly, the car drove on. What was it? “By sight” you will definitely not know anything, but if you look at the contents of the memory of the on-board computer, everything will become clear. How do Toyota self-tests start? Let's find out!
Start of diagnosis
Under the hood, Toyota has a special connector for diagnosis. In appearance it is such a plastic box on which DIAGNOSTIC is written. It is necessary to open its cover in order to see on its reverse side a detailed marking of all the terminals. After that, any suitable piece of wire is taken with which the TE1 and E1 connectors are closed. Get behind the wheel of the car, turn on the ignition (you must turn off the air conditioner and the stove), and then carefully monitor the CHECK lamp.
So, immediately after turning on the ignition, it should start blinking. If the lamp blinks continuously two or more times, then the computer's memory is empty. Take out the jumper, close the diagnostic unit and continue on your own business.
Worth knowing
Modern diagnostic units divide faults into two types: light and heavy, and in the first case, they do not clog the memory of the on-board computer with error codes. So, if for some reason a simple malfunction has disappeared, then there will be no records about it. It often happens that after driving on a bad, dirty road, Jackie Chan begins to signal an ABS system malfunction. The on-board computer will immediately turn it off. But if you just wash the car normally after such a trip, the contacts will be cleaned and everything will return to normal without any repairs.
On which model does self-diagnosis most often end this way? Toyota Corolla of some series is the most striking example, such cars are completely unsuitable for driving on domestic roads.
Some error codes
Here is an example: a flash / pause, then a flash again, followed by a long pause and a regular flash, indicates error No. 21. Another example: if there is a long pause after blinking, then blinking again and a pause, followed by a flash again, then this is error No. 12. Note that each Toyota motor has its own error code table. But here it should be remembered that most motors in this regard are practically no different from each other, since in many models some signals are simply not provided.
In addition, in most cases they have different test standards: on one model, the device can produce 0.45 volts, and on the other - already 0.5. We are saying all this so that you clearly understand: there are no fundamental differences in starting the diagnostics; only codes and reference values programmed at the factory differ.
The simplest table of fault codes is observed on older cars of a Japanese company. If the car is serviceable, then it simply blinks a light bulb, and the interval between flashes is three seconds. All faults are identified by a total of ten codes, so in this case an extremely easy self-diagnosis occurs. Toyota Corolla of the first families has just such a simplified system.
Important Notice
It is important to remember one simple rule: all engines of the Japanese concern are initially equipped with almost the same diagnostic programs. However, due to structural differences that can occur even within the same Corolla family, the signals will be completely different.
Listing them on the pages of this article is completely pointless, since these data should be available in the instruction manual of your machine directly. We strongly do not recommend using data from other models, since with this approach you may very well be able to diagnose the problem that occurred precisely in your car.
Diagnostic unit differences
On old Toyota cars there is no diagnostic unit, but there is a freely dangling “chip” with two contacts, protected by a plastic cap. Actually, its outputs are similar to the “E1” and “TE1” connectors of the new machines. If there is nothing at all, then you can take a 12V lamp and two wiring: one of them is grounded to the housing, and the second you must touch all the "suspicious" connectors. Do not worry: you will not burn anything.
When you still find "TE1", the lamp on the dashboard will go out immediately, and the on-board computer will begin to issue a trouble code. Note that when connecting the “E1” and “TE1” terminals, not only EFI diagnostics will be launched, but also some third-party blocks will be checked.
Clear memory from previous readings
As a rule, for this you need to pull out the HAZ-HORN fuse, and in other models - STOP (see the manual for your car). Sometimes there is an EFI variant. However, everything can be made simpler: throw off the negative terminal of the battery for half a minute, after which the memory will be reset with a guarantee. But only in this case will the memory in the air conditioner and the clock be erased. And yet, if you have a car of 1998 or newer, such a hard cleaning can cause problems with the work of many systems, and all this can last up to several days.
The reason is simple: modern cars can adapt to a specific driving style, and the data is also stored in the memory of the on-board computer. However, this phenomenon has a purely positive side. Many of us buy a car after one or two owners, and their driving technique was far from always satisfactory. Such a machine can eat a breakthrough in gasoline, inadequately respond to the gas pedal. In a word, she behaves badly and clearly "begs" for a trip to the service.
But before that, you can very well try to lose memory. As practice shows, this is often quite enough. In this case, you will not only save your money, but also gain considerable experience. But how to do self-diagnosis? Toyota, as we have already said, does not present any special surprises in this regard, so nothing particularly complicated awaits you.
General procedure for diagnosing ABS and TRC
This is done in the following order:
Turn on the ignition without starting the car engine. If there are differential locks, they must be turned off, otherwise the Toyota engine’s self-diagnosis will simply not start due to software limitations.
Locate the DLC 1 diagnostic unit (as we said, it is located under the hood), then according to the above “recipe”, insert a jumper from a wire or wire there. Note that the MR-2 model does not have the required connectors in the DLC 1. Look for a dangling "locket" with connectors in this case, which will hang near the engine. On the body should be written ABS.
The ABS lamp will blink, the signals of which need to determine a specific malfunction.
After that, you can clear the computer memory. It is necessary to turn on the ignition, turn off the differential locks (if any), and then quickly press the brake pedal, and the interval between presses should not exceed three seconds. When the memory is completely erased, the diagnostic lamp will flash at intervals of 0.5 seconds between blinks.
In general, the self-diagnosis of Toyota ABS is done. The jumper with DLC 1 is removed, after which the standard part is replaced. And in the case of ABS, the unit is restored to its original state.
Box diagnostics
All of the above applies mainly to taking readings from the engine. But what about the self-diagnosis of the Toyota automatic transmission? In general, there are no special differences (except for error codes, of course):
Turn on the ignition, but do not start the car itself. At the same time, the automatic transmission lamp should light up immediately and go out after three seconds. If this is not observed, then you will have to addicted to check all the fuses, as well as the physical integrity of the lamp itself and the wires.
Turn off the ignition. On the same DLC 1 connector, it is necessary to connect the above-mentioned conclusions “E1” and “TC” more than once. Engage the hand brake, and immediately after that start the engine. Now, the automatic transmission indicator should blink at a frequency of four times per second.
Start moving in a straight line: you have to accelerate to at least 80 km / h. If the indicator continues to flicker at the same frequency, then everything is in order with the speed sensors. Otherwise, the verification will continue.
Stop the car. After that it is necessary to remove the jumper between “TS” and “E1” and install it between “E1” and “TS”. We read the codes. If there are more than two codes, then there will be an interval of 2.5 seconds between them.
Clear the memory again in the manner described above.
This is how the Toyota automatic transmission self-diagnosis is performed. In some car models, it can be difficult to find the EFI unit. Typically, it is located under the front passenger seat or on the left pillar. In its metal case there is a clearly visible hole through which you can easily see two LEDs: red and green, with which error codes are issued. The red LED in this case gives tens of units, and the green - units.
In addition, there is also a screwdriver connector, with which you can select the test mode. Before starting the test, make sure that this knob is fully turned clockwise.
Other diagnostic schemes
There are two more schemes used on some models of cars of this company (in particular, this is characterized by the self-diagnosis of Toyota Mark 2). As a rule, they are used on machines of early production. Carry out this operation in the following order:
Turn on the ignition. After that, make sure that both diodes light up: if this does not happen, you will have to look for wire breaks or other malfunctions.
Using a screwdriver, push the handle all the way to the right.
In order of priority, the following codes should be displayed: 23, 24 and 31. However, other errors may appear. If this happens, we advise you to write them down.
As we have already said, the red LED is a dozen, the green one. For example, “23” will look like this: at first the green light blinks twice, and then the red light three times. Important! If the machine is operational, then after the appearance of the above three codes there will be a long pause, and then again the same signals. And so it will go on indefinitely. In particular, this is characterized by the “Toyota Karina”, the self-diagnosis of which due to such a cyclical pattern is perceived inadequately by some mechanics, as they see errors in the repeated signals.
If everything is in order, press and release the accelerator pedal. Signals 24 and 31 should remain. If any Toyota self-diagnosis errors appear, you need to write them down. After that start the car. Only signal 31 can remain, but more often 24 and 31 blink (in particular, the Toyota Camry self-test goes on like this). As in the previous case, write down (if they appear) additional codes.
Turn the air conditioning system on and off. After that, signals 44 and 24 (or one 44) should appear. Write down other commands (if any) and turn off the engine. Then erase the memory. To do this, turn off the ignition and turn the handle with a screwdriver in turn to each extreme position (starting from the left, of course), having stood it in each case for at least two seconds. Remember that removing the battery does not always help, as some old units can "hold" indicators throughout the day.
Second diagnostic circuit
In the second case, a five-mode scheme is used, which can sometimes be found in some new cars. There all the same LEDs and a pen, but work with them should be somewhat different. This approach is different Toyota Avensis. Self-diagnosis of this car is performed in the following order:
As in the previous case, make sure that the handle is turned to the right until it stops.
Then turn on the ignition without starting the engine.
The mode selector also needs to be turned fully clockwise.
After that, in the normal state, both diodes briefly light up, and then a long pause follows. Then the selector turns left, after which you can turn on the first mode. If you do not, a brief flash and pause will follow again, after which the second mode can be activated. Thus, you can get to the fifth diagnostic option.
Decoding modes
Regardless of the mode set, the on-board computer can issue all error codes that are in its memory. If you do not stop it, then after a long pause, the delivery will start from the beginning (in particular, the Toyota Corona self-diagnosis is carried out in this way). So, here is a description of all five possible options:
checking the health of the entire exhaust system;
analysis of the state of the fuel mixture;
self-diagnosis with a long list of possible errors;
check the starter, idle and so on;
Diagnosis of a specific car breakdown.
That’s how self-diagnosis of Toyota is done. As you can see, there is nothing supernatural in such a check. The main difficulty is to correctly and timely detect all the moves issued by the system and then interpret them using the most detailed instruction manual for your car.