After you fry your ECU/PCM experimenting, then have to have your car towed to a professional Good luck.

. Yeah man, had an air conditioning problem in the house, so I hired a guy to just run through the entire system to explain how everything worked. I told him i was going to do all the work myself, but needed someone to explain a few things to me. Paid him $150 for 2 hours, then proceeded to fix everything myself.. I take the same approach with my cars too.. This is good stuff and looking forward to you posting the connection to the ECU

a glimpse of the "old" yt feeling. maybe one of the last out there. huge respect man! p.s.: my first thought before searching for obd2 vids or info was "wireshark"? :D the second thought was reverse engineer the makers code... nah kidding. I would never even try that.

When you buy a scan tool you are buying a regular tablet and software. it is the software that is valuable.

After you get into by directional Scan tools, there is also a huge jump in price when it comes to special functions (airbag reset, relearns, etc) , and then there is another jump in price when it gets into key programming, and yet another when you get into ECU reflashing. I wonder what the limits are.

This is exactly what I have been thinking about with the elm327's. The hardware can communicate bi-directionally but no software or apps have been developed to do it. I think it's bs that all of these companies charge so much for software & readers that has been the same code for years with minor tweaks.

Content from the real engineer is here. Thank you.

This is single most important video on Car Diagnostics, targeting a subject which absolutely no one talks about ... Like, how companies are controlling the scan tool market by downplaying on their products due to the price. Also, you're are an amazing teacher and a sketcher haha 😀

Thanks Roudter, I been wanting to do this myself but you just gave me a headstart.

Exact same mindset towards your average mechanic. I'm learning WinOLS at the moment so I can avoid mechanics who do random tunes in my area. Lovely video, thanks for the upload.

As an electronics engeneer student this is amazing, I have no other comment to make, thank you for your work :), hope I can contribute to it in any way, shape or form

Just what I’ve been wondering for a while now, thank you

The action that most DIYers want from a scan tool is ACTIVE TEST That sort of bi-directional communication allows us to test individual modules and components controlled by that module. The ability to single out window switch or a window motor on each window for example. There are scanners in the $500-800 range that can actually do a great job and also make keys as well. Granted they also have subscription or update fees. Great info here. Great video. 👍🏻

You are correct about your definition of bi-directional that the scan tool manufacturers are misusing. What they actually mean is the ability to send commands to the car's ECM/PCM to control certain systems. Those high-end scan tools are supposed to be able to send more commands to more car models than the lower end scan tools. OBDII is an emissions standard that has to follow certain protocols for communication with the vehicle. Outside of that the car manufacturers can choose their own communication protocols to use for other systems in the car. Typically the manufacturer's scan tool will access & control more functions than a generic scan tool. I don't know if the communication is encrypted, passcode protected, etc., but they do not have to allow you total access. It must be proprietary since they designed it (wrote the code for it) & they are not about to give it away. If it's OBDII related that's good, but outside of that the manufacturers' are not required to give you total access to their vehicles' systems.

I'm with you man. Keep up the good work.

I bought a th inkdiag that requires you to communicate with the internet to use it. It is "bidirectional". I used it to take fuel out of my truck and the next time I tried to use it it was dead. I think they shut it down on me because I wasn't using it to fix my truck. I'm the same way I only work on my own stuff but I feel like I don't even own what I buy now from this situation but how far do you have to circumvent companies? I was paying a yearly fee and I bought the device.

Thank you. Your video is exactly what I was looking for.

You should make a donation page . So you can get this up and running .

Hi thank you for this explanation. Did erase the video where you are showing how you developed your application ?

Great video!!! I wonder how this project is going. I want my cheap dongle to do everything too. Consider the this vendor unlocking. Your awesome!!!!

Thank you so much for this

Very intelligent video, thank you very much for explaining how we are ripped off by some manufacturers.... I bought your software and about to test it right now. Just one question : can this clear P errors as I have P252f witch means "oil level high" but it's calculated on base of DPF regeneration counts not level sensor?

You got it right the first time: O.D.B. luv im. P.S. great flow of thought. I feel your enjoyment of breaking out the bits.

Biggest issue I've found is car diagnostic has its own terms that are already pre-established terms that are butchered, if you understand software design you'll find yourself headbutting a wall talking to car guys. Arguably it's the software with the predefined codes that dealer specific that you want to recreate

While you did make a fair point about the confusion over the application of term bi-directional, what I think you’re missing is where the real cost, complexity and inherent value resides: the auto manufacturers own proprietary code that controls every function of cars built today. Theirs is no more open-source than apple iOS or MS Windows. The hardware component - the connection interface - is of little to no value compared to the programming IP and they have yet to hand over access to it without collecting a license fee upfront.

Very true, it's all software. A scan tool that connects to a PC would be a good option if you can just get the software to do all the things you need to keep your car happy. But companies be selling you $3000 hardware that still won't do what you need 🤦

great video mate and great content. do you have a windows version of your application, i rather have it on my laptop?

Very impressed

If pressing a button on a OBD2 scanner sends something to the car, and the car responds by showing you new information on a screen is Bi-directional, then so is using a remote for a TV. It's the exact same thing.

Good video, ive been wondering this exact question for years. Essentially most apps that have higher feature sets are locked to their hardware at high point. I would love to have a great functional app that would allow me to talk to systems more indepth. True scan tools are just way too high for the average weekend guys

Explained so well

Thank you , keep on the good work

do you have a recommendation for obd and ecu diagnostics software for windows i notice yours is for andriod

Great video and subject!!!

Yr doing great. OBD grew into an industry money making monster. Especially when u lose yr keys.

Quick question what programming language are you using to program that software im a diesel mechanic and have picked up coding after work i really want to learn hoa to create ,y own software

It's not about what 'bi-directional' means, it's how it is interpreted. This is exactly how companies are getting away with calling their 'code readers' bi-directional tools! Hardware, Software , uni or bi it makes no difference? If it can't turn the cooling fan or fuel pump off it's not considered bi-directional. If I can't re-program the ECU to avoid an $800 dealer fee it's not considered bi directional. I hate to sees an $80 code reader advertised as 'bi-directional' because it's meant only to deceive. Listen, I in total agreement with you only from a different point of view. And I REALLY commend you for taking the time to educate. But until your software is readily available most of those in the market to who can neither code their own app or have the ability to re-program a crippled IC will just be getting screwed out of their hard earned money by using bi-directional in it's proper context. Just Say'n

Hey, have you heard of comma Ai? it is a device that can make your car autonomous. Now the thing is to do that, they connect to your OBD port. I was wondering how can they control the steering wheel via the ODB port?

So, shouldn't you be able to clone the expensive dongles like say from Launch?

I was just thinking about this the other day. How does a scan tool erase codes without talking to the vehicle? I just watched a video comparison of bluetooth dongles where some didn't have bidirectionality yet could do coding. How?

2 years later still relevant

Awesome.

is there any way to power these kind of dongles only when the key is inserted/turned to the on position?

This is cool salute bro

You are making the classic mistake of trying to apply the common definition of a term in one industry with the same term in another industry. When I use the term 'interface' when talking about computers it has a different meaning than what an 'interface' is to a seamstress. 'Bidirectional' in this context is not talking about the communication being 'talk only' or 'receive only' but rather that you can actively control outputs rather than just reading inputs.

great video thanks

Seems to me the buzz surrounds bi-directional control not bi-directional communication. Control requires communication but communication does not infer control.

If you're able to create Bi-Directional obdII software for PC I will be your first customer.

Amazing video! Keep it going..

Great video, All I need is the GM command string to force all I/M readiness tests to run without countless drive cycles. My Evap repairs are complete but readiness wont set. Drive cycle is difficult to achieve precisely. I.E. red lights, speed limits, blah blah blah.

"Update" is paid subscription to unlock functions ? " upgrades" are paid yearly also?

Your app on your website is listed as ODB instead of OBD. Also, do you have any plans on releasing source code? EDIT: I didn't finish the video before asking for the source. Thank you.

Can this software be programmed in a scripting language such as Python? I notice that you're using C#. I ask because I have some experience with python and just recently have become interested in OBD.

Each manufacturer writes different Canbus message depending on how the modules work and are wired. Technically yes you are correct, but you pay thousands for the RnD of the companies making the Scan tools. They have to write software to handle each manufacturer and sometimes each model of vehicle from that manufacturer. I would love to see this distributed for free but I doubt many people are willing to invest many thousands of hours in reverse engineering Canbus messages of each manufacturer, just for the good of mankind. If you are that person I'll be the first person to download that software. Goodluck Sir 👍👏

Protool does this for bmw already can control all kinds of components on the vehicle like front seat fuel pump windows etc

I have to pause sometimes to get the order of OBD correct (not as much as PVC and PCV). But I noticed that in your code you have ODB..., do you have problems where in one place you used ODB and another OBD for the same variable/function? I could see that leading to a lot of extra debugging time. :-(

Can this be used to write and change a vin number on a ecu for example?

Can tell he isn't a car guy. Bi-directional control is for testing modules for diagnosis.

So..... Is it possible to have the wifi/Bluetooth device, send a signal to a satellite, have the satellite send the signal to a vehicle, have the vehicle send voltage to the part you want control over?

Thx u thx u❤

So my TV doesnt communicate back to me? What planet do you live on? Unless your remote is broken like mine is ,a television very certainly communicates back in response to a channel change, on and off, raises and lowers the volume.

Haha that’s awesome my dude! My frigin car has been sitting in my driveway for far to long!.. long story..

what is the name of the website that he mentions in the video please...

Of course the scan tool has to talk to the ECU/PCM. But, I've always interpreted bidirectional as meaning that the tool can WRITE to the PCM as in modifying the spark advance curve or on a variable valve timing engine changing the timing parameters. Generally the manufacturer tries to strike a good balance between fuel economy, reliability, drivability, and performance. But, you might wan to optimize for one of hose at those at the expense of the others.

The problem is each car needs to be tested, graphs need to be displayed. To take care of each car is a big project. $400 gets you delivered to your door step a rubberized case fast android computer the dongle built in and everything loaded. One repair has paid for it. Bi directional means physical things are changed on the car not just read values. On the higher price units you pay for support.

Does your app work on ios, windows or Android?

I would approach the subject with a large 4x8ft pegboard $30.00 with all "used" components normally installed into vehicle on one side and on the backside of the 'chalkboard easel' I would have plug and play breadboards (prices vary) to provide various conditions to which each of the components provide values for. pin on plug style adaptation, you would be able to provide all attributes. A simulator would be another possibility to feed into this. However for what you're trying to do you could have this open source software and everything else for 1/20th of what you say is $5k.

Of course all ELM devices are rudimentarily bidirectional. However, when a legitimate company offers a bidirectional scanner/programmer we expect it to be able to run brake bleeds, change combustion points, run maintenance procedures, etc. If you can figure out how to run those, not just read and clear DTC's, then you have something! Keep working on it, you're on the right track, but its still not there.

subbed!

does this work for IOS/Apple phone?

Oh how I need to ping my ABS and kick the bubbles out of its nooks and crannies on a 2000 Chevy Express 1500 5.7 liter. Who offers software to do this. 05/19/2022? Does the manufacturer hide the code and or require the purchase of the code to activate such devices? Is this part of the high prices we see?

Likely not an ELM327, but something compatible. MY OBDLink SX advertises being based on that; and, there's free 3rd party software that let's me clone gen 3 LS ECUs with it (PCM Hammer).

can you share your source code for the application

I agree with the TV analogy but if cellular devices weren't bidirectional, you couldn't watch KZfaq or open websites and etc. It's a little misleading. Cell phones and other wireless devices do upload data and send requests.

I would be interesting to do a teardown of a ktag or similar device to see what hardware it uses. My suspicion is it’s more than just an elm considering the size of something like a ktag is much bigger then these cheap dongles. I wonder if it would be possible to load a new tune onto the ecu/write to its eprom just using an elm.

I have always thought this. I have thought it was a software issue.

I agree with one of the comments you should make a patreon page so thay you can further your experiments that come to fruition, a good tech can diagnose with simple dongle a powerprobe and an oscilloscope bi directional is just a luxury in a scanner thats it

Nice bro with this i will subscribe on your channel

Most of these very cheap ELM327-labelled adapters from China have Microchip MCU PIC18F* inside, or similar. And this makes me suspect the ELM327 original one chip might be a re-labelled microcontroller itself, because, I have doubts that Chinese have reverse engineered the original ELM327 chip so deep to make its copy for their mass production of very cheap interfaces on its basis, perhaps an MCU firmware just leaked.

I think the part about these scan tools not being special is only half true. If you look at the disassembly of a of a high quality J2534 unit, you will see tons of solid state relays inside that these cheap OBD readers don't have. Maybe certain cars require certain wires to be shorted to perform certain functions or something like that. Excited to see where this goes though.

I think 'bi-directional' scanners can be had for $250 now. That plus a bus pirate...

you know they mean Bi-directional as in the toll has the software to do the special functions reset program or flash that are bi-directionally controlled not all tools can open the valve or actuate the solenoid ..some can only read codes and delete codes some can do do actuations but not reset or program some can test but not Reset and some can FLash or reinstall new PCM ECU software ..so when they say Bi-directional it mans the tool has the ability to Reset Actuate control and program and do so on an almost OEM level .......... where most cheap tools can only do basic open source resets common test and read and delete codes ..your soft ware that your Elm uses will never be able to do what a Bosch otc snap on autel launch or Topdon Professional tool can do and will never be able to do OEM level functions programing resets ....................For Example Forscan ..use an Elm you can only used 76% of the software's functions as the hardware can not do it ..but if you hook up a real VCM2 you can do 100% because the tool has the hardware to do it .....so YOu have no clue apparently its not juts the software the tool or VCI is a huge part and your ELm will never be able to do teh same as the hard ware does not support the functions .......... and I know this because I use OEM software's and I also make Custom software's........ and I even got GDS@ and IDS to run on a Elm but it could not even do 60% of the IDS software ...

Not the ol dirty bastard 2!!! 🤣

This Obdwiz Windows app has a Console Mode that allows direct entry of OBD commands when used with any of the OBDLink devices. Perhaps this allows more control than a typical OBD device?: kzfaq.info/get/bejne/i91knduCttCxkZs.html

Very interesting, most of the expensive scan tools are just gloriified Android tablets or Windows in the case of Snap -on. It would be great if some company would sell the software at a fair price without the need to buy their overpriced tablet.

When people refer to bi-directional scan tools, they are referring to re-lean procedures or ability to actuate functions. A scan tool which can send commands to the vehicle. For example, TPS reset or relearn after cleaning Throttle body etc. Bluedriver cant do that even in 2022. On the other hand, dealers use brand specific diagnostic and programming communication devices which can erase & upload chip specific software. Also, newer vehicles are nothing besides rolling complex machines all connected through CAN bus system just like human nervous system. Tons of data send & received through these network of tiny chips. Dont expect dongles or OBD-2 to flash CAN bus chips since most of these software's are proprietary & only available to dealers by manufactures. When hackers get access to these proprietary software's, they can literally flash & rewrite many essential commands which can give total control to them. Dont be surprised if you see these softwares listed for thousands of $$ on darkweb. Ignition switch module hacks for KIA & Hyundai are hot these days & watch out for a random car parked waiting for you to pull in & duplicating the codes for locking & unlocking through RFID hack.

Its all software and knowledge of the developer to incorporate the functionality of the software on the can bus network , ability to switch between hs/ms can while knowing the as built data coded by the vehicle manufacturer on the ecu to communicate to the various modules.. look into forscan for instance, its free software for only ford. Yet for free youre able to literally do anything expensive ford software can do via elm link.. the as built data is read and allowed to be changed/ flashed. You can totally brick your ecu and cause it to blue screen if you change part of the code the ecu uses to perform self checks or whatever.. i owned a ford ranger and thought i knew what i was doing but i made a mathematical mistake and when the fuel pressure was being displayed as per .5lbs to 1 scale. Like 5 lbs is actually 10, 2lbs =4.. well i entered it in as thinking it was 1:1.. so when i put in manual fuel press of 90psi it told the pump to run way past its ability, blew the injectors wide open and hydrolocked the motor with gas then proceeded to blow the intake clean off. Was sitting in the grocery store parking lot. All the sudden the truck dumped a quarter tank in the cylinders in 5 seconds. Burned the pump, all 6 injectors, intake and throttle body was gone…. Shit just died.. right after i hit enter.. lol.. good times..

ELM327 is a cheap option but not a good option, most professional adapters do not use an ELM327 due to its limitations. Nexiq, Tactrix, Machinna, SnapOn, OTC, they will all have their own hardware for the specific protocols they support.

programming a CPU or ECU is a function of bi-directional activity.

This concept is about protocol orthogonality, not "bidirectionality". A protocol (as accessed by a given API) will be called orthogonal if for each data element you have access to all the possible functions. These will typically be "read", "write", "clear", "set" etc. for all usable data. In reality, certain elements, like engine speed, may not be amenable to writing. Some protocols are just not complete enough to be orthogonal, and in other cases a system may implement various access levels for different classes of users.

You pay for functionalities to do certain useful things. I agree that what is being charged for some of these functionalities is just ridiculous.

Shiiit now I can sound like I know what I’m talking about next time I tell the cute lady in my office I can help find out what’s up with her car 😏

Oh are the one? should we go to the lady who bakes the cookies

Why are there No tuner or program ers using ecu flash the software is super easy and free works with tactrixs cable obd2 to usb its super easy I want to try a rom and bin for a chevy In my library and see if that will work as ceddy mod or hondata with the chevy would be super easy and nice

Probably licenses to get past hurdles to make legit software that can manipulate the car. Maybe it has to do with epa mandates on the auto companies who knows.

Open source the world through ecu flash

That's not how cell phones work

Unfortunately, this guy's lack of understanding of how all of this works will result in him not getting very far at all. He's got to go back & read the OBD2 spec in detail, and understand how the ELM327 actually works to translate the standard OBD2 electrical signaling to a simplified, higher-level serial interface. All of the bidirectional control stuff is proprietary & closely guarded info that isn't published by the auto industry & that you have to pay big money for in order to get access to. It varies greatly by manufacturer & year, and can change greatly with each release of a new model. The 'big money' scan tool manufacturers have commercial agreements with the auto manufacturers & pay a lot in order to have access to all of the necessary information & tech support they'd need to build their scanners. This access costs them a shit-ton of money in yearly premiums in order to have all the lastest, up2date info. This is an expense which they then happily pass on to their customers. IOW, unless you know a guy that works at Snap-on, or a guy in China that works at a scantool factory, it's gonna be almost impossible to get this info. This won't be as easy as finding a leaked 2-page datasheet that explains what commands / signals you need to send the ECM; I wish it were that simple, but it's not. Without knowledge of the specific command sequences you'd need, and the response values, you'd be flying completely blind, and have absolutely no way of knowing what you're doing. As such, you also risk seriously fucking something up & bricking your PCM/ECM. Also, for some makes&models, the physical logic signalling for the manufacturer-specific modules might not even be OBD2 compliant at all; there might be some protocols that are super proprietary & unique to a given vehicle line, and that require special circuitry & logic in order to process & interpret. In such cases, an ELM327 chip would be useless, as it's only designed to work with the 'standard' OBD2 physical signalling protocols. FYI, I'm also a DIY mechanic & programmer/electronics geek. So, I'm not like some advocate for the high-end scantool industry, nor am I some pro mechanic who's angry he paid $5k for a nice scanner, only to see that the nerds are now trying to hack their way around having to pay what I did. I looked into all of this stuff myself when I was trying to find a way to do basic bidirectional control (in order to activate fuel pump). I came to the conclusion that, as of now, it's basically impossible. There would have to be a MASSIVE leak of info from the auto industry (or from a big scantool maker) in order for this to change. Edit: The only other way I can think of in order to get at this info would be to have access to a high-end scanner that does everything you want, run through every possible bidirectional command between each make & model you're interested in, and then sniff & document all of the electronic signalling that goes on between the scanner & the vehicle. It would take thousands of $$$ of initial expense to get the scanner in the first place, and then hours upon hours of testing, probing, deciphering, etc., and then you'd still need to write a bunch of code & do testing in order to see if you can make it work (FYI, this is most likely how the chinese scantool manufacturers do it). So, you'd basically be creating your own pro scanner by reverse engineering a commercial one, at which point, I highly doubt you'd be willing to give it away for free (unless you're really rich & bored). After that, you'd most likely start getting cease & desist letters from the automakers, so get ready to have lawyers on retainer.

This guy does not completely understand what he is talking about. He is being too literal. When you attach a code reader it is only reading. Bi-directional should be called bi-directional control. Not all readers/scan tools use dongles, some are hardwired, so does that change the definition? This video is worthless and only confuses the less educated.

This video explains a basic premise terribly. What He misses is the simple idea. He doesn't understand is that the communication is bidirectional but the difference with the bidirectional tool is that it allows the tool to directly effect the vehicles function. The only bidirectional function on most low end obd 2 tools is to clear three dually codes. So communication is bidirectional but function commands are not. I hope that helped.