The computer of the R129 remains somewhat old, in any case before 1995, the year when it passed to the OBD2 standard and when it was necessary to have modern and expensive systems to maintain them.
Owners of models before 1995 equipped with the OBD1 standard are in luck: with basic equipment, they can communicate with the computers of their R129.
Many know the basic system which consists of a switch and a LED.
With this rudimentary system, it is possible to reveal the fault codes by counting the flashes of the LED after having set the terminal of the computer concerned to zero level for a determined time.
It works perfectly and the vast majority of SL owners use this system. However, this system does not include any safety and a bad connection can have catastrophic consequences.
You have to manipulate the system with precision and you must above all not take your eyes off this LED which can flash up to thirty times. Being distracted for a single second and the code given by the number of flashes will be wrong and you will have to start over.
I had the opportunity to see owners of SL redo several times the same manipulations. and when it comes to clearing a fault, you have to manually restart the scan to check that this code has indeed disappeared.
As you can see, this is not very practical.
Hence the idea of making a device that is simple, secure, and which, above all, makes it possible to read faults without having to count flashes or keep a button pressed for several seconds.
A first version was born in 2013:
Fully analog device, and an operation iblameless,the many components necessary for its operation made it difficult to achieve.
A few tens copies have still made people happy and many still use it.
Then, the idea to then design a better and simpler tool came. IIt was a question of reviewing the whole system and moving on tomontage digital.
The device has therefore been redesigned and redesigned from the start, only the case has remained the same.
A second version has therefore emerged.
It is equipped with a microcontroller and function management software. No more transistors or logic circuits participate in the operation.
First advantage: It is much simpler, the number of components has been divided by 7, and if the cost price is still high, it is much faster and easier to manufacture.
Second advantage, the code reading and erasing functions are automatic. No need to keep a key pressed, just touch it to trigger the selected sequence, and, if it is erasing, re-reading is triggered automatically afterwards to check that the fault has been erased.
Clearly, pressing only one key erases a fault, returns to read mode and verifies erasure.
All the users of the device are unanimous, they say: "THIS IS SUPER"!
The device is also equipped with a car battery voltage meter, which avoids many worries. Indeed, during the tests, it is necessary to switch on the ignition on the vehicle and there is a fairly high power consumption.
With a somewhat aging battery, the voltage gradually drops and when it reaches 8 or 9V, malfunctions occur, not because of the device itself, but because of the vehicle's computers which are underpowered.
The built-in voltmeter permanently displays the voltage and gives a valuable indication for the user.
The connecting cords are not made of PVC, but of silicone. This material gives them flexibility, comfort and longevity.
Manufactured in small series, the device is assembled by hand. Each finished printed circuit is tested on a bench before assembly in the box, then the device is finally tested after assembly is complete.
It is then pre-packaged.
Before shipping, the device receives a new test, its final packaging and then leaves for shipping.
This rigor allows an almost zero rate of return and ensures the user long-lasting and reliable operation.
I am certain that this device will give you complete satisfaction and in any case, it costs you less than a diagnostic step at your dealership.
Good luck with Diag002
