It’s no real secret that modern-day cars are basically a collection of computers on wheels, which also means that we get all the joys of debugging complex computer systems and software with cars these days. Rather than a quick poke under the hood to rebuild a carburetor and adjust the engine timing by hand, you’ll be pulling out a scan tool to gain access to the computer and figure out why the darn thing won’t start after someone else used a scan tool on it, as happened to [DiagnoseDan].
The question was whether the third-party scan tool that was used by the owner had done something to the software settings that would prevent the engine of this 2012 Renault Megane RS from starting, such as erasing keys, or if it was something more subtle. With no stored fault codes and the engine having healthy fuel, spark, and cam sensor readings, the conclusion was that the ECU was not doing its fuel injector things for some reason.
Ultimately, the root cause was that the ECU had been modded, with a re-mapping performed in 2020, meaning that the scan tool that [Dan] was using couldn’t properly interact with the ECU. Reflashing the ECU with the original manufacturer’s firmware was thus the next step, which is pretty involved in itself.
Reinstalling the OS on the car proved to be the solution. Likely, the modded firmware had stored some fault codes, as the ECU normally doesn’t start the engine if there are active codes stored. The third-party scan tool was thus likely blameless, but the inability to just clear fault codes was the real issue.
I’ll save you from this very obvious rage-click-bait-thingamabob: nope.
The ECU got broken because owner used a scan tool to tinker with ECU settings instead of just reading fault codes.
Indeed, not in this instance, and never just by reading and clearing fault codes unless something hypothetical has gone very wrong with the ECU.
but you also hint at the way that a scan tool can kill your car. If the scan tool has write capability and access to non-OBDII parts of the system, it’s sometimes possible to change settings that will result a genuinely non-recoverable, engine-mangling event the next time you try to drive.
Doing this by accident rather than stupidity or malice still seems highly unlikely to me. Much better chance you’d end up like the car in the article, and the car will be ok again once things are restored to a sane configuration.
Hate to contradict, but yes a ‘scan tool’ can absolutely kill a car. I bricked my dad’s s type Jag (the modern kind, obviously) several years ago and it had to be taken in to jaguar on the back of a lorry just for trying to read fault codes with a cheap Chinese Bluetooth reader and it’s android app.
It had a minor warning light before I started, after a quick read and not attempting to mess with anything it had every warning light on, and was totally dead.
Now I have no idea what the app did or how far off spec the obd adapter was, clearly something went wrong, but the summary is you absolutely can kill a car with one without any attempt to do anything at all risky.
There were a few VWs where reading the ABS module had a chance of bricking the module.
I had a VW where resetting the airbag light after removing the seats had a small chance of deploying all the airbags
I’m 100% sure you had a XF 2009-2011 and you had the keyless entry key IN range and remove the battery terminal! Known software corruption of BCM
I’m 100% sure that my dad’s s-type was not also an xf as that’s a totally different model. Also no battery was removed.
“I’ll save you …”
UCSD has done a bunch of research on automotive vulnerabilities, include attacks on cars using OBD2 scanners, and looking at vulnerabilities in the OBD2 scanners. It is possible to kill a car using a scan tool, as well as other stuff, such as disable the brakes once the car goes over 50mph, then erase any malice code once the airbags deploy. It is possible to compromise the OBD2 scanners so that the user doesn’t know it is doing bad things to the cars it is used on.
https://cns.ucsd.edu/experimental-security-analysis-of-a-modern-automobile/
Remember that if you have a used car, you don’t know what kind of modifications the former owner could have done. If that’s you, and you go to scan your OBDII, the effect would be about the same. Suddenly you can’t drive to work because you connected a code reader under your dashboard.
People have a very loose definition of what constitutes clickbait, furthermore how on earth is this ragebait? Only a rage addict could say something like that.
Thanks a lot for this SparkGSX. That guy ScammerDanner is known for his clickbait material!
The scan tool won’t kill the PCM, it can turn of sensors, switches, solenoids if it is bi-directional. Can be hard to figure out if the person using the tool isn’t familiar with a automobiles configuration. For individuals buying scan tools that aren’t trained professionals, a simple obd2 tool is sufficient. No need to look cool buying a high grade tool if they don’t know how to use it! Kill it, NO! Technical difficulties from tinkering, YES!!
thanks for this comment!!! Sc@mmerDanner is known for his clickbait content!
More depends on your choice of words. To my wife, the car has died AND needs to be immediately replaced with a 2026 lux wagon preferably german make. My mechanic sees visions of large bank accounts. The geek in me says gimme a couple hours and a good scan tool with write capabilities or a replacement ECM.
I’d love to see a really mature open source ECM project on here someday, that has a big library of configurations for different makes and engines. That would be cool. Probably there are already a couple iterations of this floating around somewhere.
https://rusefi.com/
https://speeduino.com/
http://www.diyefi.org/ (woot! No SSL!?)
When I worked for Toyota, one of my former automotive instructors had come in because they were demonstrating using the scan tool on one of the college’s Priuses and it only had the ability to interact with the engine computer, it cleared something that made one of the other computers unhappy and it refused to go into “Ready On” (equivalent of “engine running”) and had to be towed in. We weren’t sure what exactly caused it because there were not any codes set and doing a code erase from the Toyota scan tool (Clears all of the computers) fixed it.
We called Techline (Technician assistance) and they had us dump the memory and send it to them before clearing it and they were stumped too but apparently the engineers in Japan were quite interested in the problem, never heard if they came up with a root cause, but the instructor did say that they’d done it several times before with no issues…
” The third-party scan tool was thus likely blameless, but the inability to just clear fault codes was the real issue.”
umm no. The third party scan tool was the wrong tool. The quote is like saying ‘using a screwdriver to release the bolts didnt work. Once we replaced all the bolts with screws the screwdriver worked fine. So the screwdriver wasn’t at fault.’
But the screwdriver wasn’t at fault. Not in the slightest. The only tool at fault was the tool who attempted to jam a phillips/flathead screwdriver into a hex head bolt…
Scan tool “shouldn’t” cause any issues – unless – it’s some janky chinesium garbage.
What’ll absolutely trash the engine & power train on a vehicle is an incompetent “tuner”.
And that has zero involvement with reputable scan tools (ie. Snap On models), or ancient
GM Tech2 (for the boomer LS1 audience). PSA, be wary of chinesium Tech2 clones !
You get some clown with HP Tuners, EFI Live, etc entering WAG’s for critical values,
kiss your mechanicals goodbye. All manufacturers want the dealerships to capture
the digital forensic evidence in the ECM, PCM, etc modules to check for tampering.
If there’s anything suspicious, engine & power train warranties are voided on the spot.
You want to play, be prepared to pay (as a lot of Ram truck turbo diesel owners
found out – after their modded engines blew up and drive trains had “unscheduled
disassembly” occur). Outright warranty denial (ecm, pcm were monkeyed with –
not what left the factory, so 100% morally correct to say EffYou to the owners).
I do hate what cars have become… I used to drive a Mercedes Vito, an OK bus in many respects, but did it really need to force me to drive 30 miles home in limp mode (at 30mph) when the intake airflow sensor failed? Where’s the harm? A warning light would have done the job. When I replaced the offending part, it still didn’t work… a forum post informed me that I needed to delete all the adaptation data in order for the thing to accept the new part. After an expensive visit to a Merc specialist I ended up buying one of those knock-off Xentry rigs/multiplexer from Aliexpress, which came in very handy over the following few years. Like when the left indicators started flashing permanently. Or when the windscreen wipers came on and couldn’t be turned off, etc, etc.
I’ve owned a Renault Megane too, and all I’ll say here is that IME they need no help from a code reader or any other outside agency for the electronics to grenade themselves. The key card ignition provided an extra layer of security in that it was nigh on impossible to start it even if you were in possession of said key, and the dash was lit up like a Christmas tree most of the time.
In-built obsolescence in cars used to be provided by rust; here in the UK in the 70s we had Fords which were being welded by their 3rd birthday, and in the scrappers by their 8th. Now, the electronics fail and the cost of replacement parts and specialist mechanics makes them uneconomic to repair. Nowadays I have a diesel Dacia; it’s about the most primitive car I could find. Long may it keep going.
You can buy a used Tarpan Honker with Andoria 4C90 engine. It has ZERO electronics and since it’s a diesel using a classic inline injection pump (none of that TDI rubbish) it can even run underwater as long as you supply air via snorkel. It’s one of the best 4×4 cars ever made and you can fix it with a flat screwdriver, hammer and a bit of tape.
PROTIP: Don’t buy Honker with Iveco engine, those won’t last 200kkm without major failure and they’re very expensive to repair.
I’d never heard of the Tarpan Honker; while it might be a bit OTT for my needs, it looks absolutely heroic!
Bet it can’t kill the one I just downloaded.
Sorry, accidentally reported.
HaD really needs to add an “Are you sure you want to report this comment?” verification, or an “Oops! Undo ‘Report comment’.” Or at least make the text red or brightly contacted with the dark grey background.
It’s WAY too easy to bump the ‘report’ link on a tablet.
My apologies Ostracus.
As an act of revenge, I just hooked jumper cables to an old IBM.
Computers have as much business in cars as glow-plugs do in smartphones
Slightly unrelated, but how cool would a cell phone rockin’ vac tubes be?
I had a hand in developing open source software to reflash the PCM in General Motors Gen-III V8 vehicles (“PCM Hammer”), and along the way I soft-bricked a couple via the obd2 port. They were recoverable, but they had to be removed from the car and opened up on a workbench first.
Once you start writing to flash memory, you run the risk of flash corruption. At power up it uses a checksum to verify integrity, and if that test fails, it just goes into a panic mode. And of course if you corrupt the boot block you’re also in trouble.
This is less likely to happen if you’re not actively working on reflash software, but if you interrupt the flash process with a nice mature commercial tool, you can end up with the same checksum failure and panic mode.
Newer vehicles with more RAM are probably more resilient to this kind of thing, but we were targeting 99-07 units and there wasn’t room to buffer an entire flash block in RAM. So, during most of the process, a block has been erased and only partially written. If the battery dies, that’s bad news.
Hey! Is that a Liquid Yellow Renault? One of the Twingos in that colour has the Megane RS engine in it
I generally has an OK view of Renault, but now that they started making weapons that view has turned, and it would take a bit to clear that fault code.
had*
Yes this Renault FT initiative is disgusting :-]
… so the logical question should be “WHERE are the mandatory non-negotiable regulations”?