Tesla Recalls Cars With EMMC Failures, Calls Part A ‘Wear Item’

February 11, 2021 by Lewin Day 150 Comments

It’s a problem familiar to anyone who’s spent a decent amount of time playing with a Raspberry Pi – over time, the flash in the SD card reaches its write cycle limits, and causes a cavalcade of confusing errors before failing entirely. While flash storage is fast, compact, and mechanically reliable, it has always had a writeable lifespan much shorter than magnetic technologies.

Flash storage failures in the computer behind Tesla’s famous touch screen are causing headaches for drivers.

Of course, with proper wear levelling techniques and careful use, these issues can be mitigated successfully. The surprising thing is when a major automaker fails to implement such basic features, as was the case with several Tesla models. Due to the car’s Linux operating system logging excessively to its 8 GB eMMC storage, the flash modules have been wearing out. This leads to widespread failures in the car, typically putting it into limp mode and disabling many features controlled via the touchscreen.

With the issue affecting important subsystems such as the heater, defroster, and warning systems, the NHTSA wrote to the automaker in January requesting a recall. Tesla’s response acquiesced to this request with some consternation, downplaying the severity of the issue. Now they are claiming that the eMMC chip, ball-grid soldered to the motherboard, inaccessible without disassembling the dash, and not specifically mentioned in the owner’s manual, should be considered a “wear item”, and thus should not be subject to such scrutiny. Continue reading “Tesla Recalls Cars With EMMC Failures, Calls Part A ‘Wear Item’” →

Custom Ignition For A Citroën Mehari

February 5, 2021 by Lewin Day 42 Comments

The 20th century saw a great many cheap, utilitarian vehicles enter the marketplace. Cars like the Mini and the original Jeep offered low-cost, no-frills motoring. However, they were also decidedly low-tech, and not as reliable as modern cars by a long shot. The Citroën Mehari fits into this category neatly, and when [FVFILIPPETTI] grew tired of the unreliable points ignition system, he decided to build a more modern replacement.

The system is based around at ATmega328, the venerable chip many are familiar with from its starring role in the Arduino Uno. The chip tracks engine position with a magnet mounted on the flywheel combined with a hall-effect sensor, passed through an optocoupler to avoid nasty high-voltage spikes from the spark system interfering with the microcontroller. The chip then charges the ignition coil and fires it at the necessary time to ignite the air fuel mixture.

Old-school mechanical ignition systems were, if we’re honest, terrible compared to more modern solutions. This build has rewarded [FVFILIPPETTI] with a far more reliable ride, which we’re sure is very satisfying. If all this hacking has you thirsty for an automotive project of your own, dive into our primer on how to get into cars!

Upgrading The Batteries In A BMW I3

February 1, 2021 by Lewin Day 42 Comments

The BMW i3 debuted on the market in late 2013, one of the brand’s first electric cars. Also available with an optional range-extending engine, early models featured a 60 Ah battery providing up to 130km range on a full charge. However, times have changed, and over the years, BMW have updated the model with larger capacity batteries over the years. So what does it take to retrofit an older model with the newer, fatter, juicer 120 Ah pack?

It’s all helpfully laid out in a video by [Daniel], who notes that it’s not a job for the faint of heart or poorly equipped. The good news is that, mechanically, the newer batteries have the same external dimensions as the older packs, meaning they can be bolted in without requiring any cutting, welding or, adapters. But that’s about it for the good news. The batteries are cooled by the air conditioning system, meaning that removal and replacement means draining the system of refrigerant using highly expensive specialised hardware. Additionally, many batteries in crashed cars are disabled when the airbags are triggered for safety reasons, requiring unlocking through BMW’s proprietary software or replacement of the internal battery controller. Then there’s the usual laundry list of gradual changes that happen across any automotive line, meaning that certain model years and trim packages can have incompatible plugs and connectors or other features.

Overall, it can be quite a bit of work to do, and with the tools required, something that needs the services of a dedicated mechanic’s workshop. However, find an experienced shop that regularly works with EVs, and you might find they can facilitate the upgrade for you without too much fuss. We’ve seen [Daniel] tackle upgrades before, such as a much easier swap on the Nissan Leaf. Video after the break.

Continue reading “Upgrading The Batteries In A BMW I3” →

Bugatti Concept Car Shows 3D Printed Strength

January 31, 2021 by Al Williams 30 Comments

We doubt you’ll be driving a Bugatti Bolide anytime soon. It’s a bit of a showy concept car, and it really is pushing some limits on what you can 3D print in an automobile. As you can imagine, they aren’t printing car parts out of ABS or PLA. According to The Drive, the prints use selective laser melting with titanium to make some impressively strong and light parts.

It isn’t just the material that makes the 3D prints strong. Bugatti actually patented the internal structure of some parts which are almost bone-like. By having the parts largely hollow, the weight is cut. But fine internal structure creates very strong parts. How strong? A 3.52 ounce pushrod can handle up to 3.85 tons. The printed titanium is apparently heat-treated to increase its resistance to fracture strains.

In addition to titanium, some of the concept car’s parts are printed ceramic which insulates some components from heat. The printing process can apparently get resolutions down to 0.1 mm. Many parts are quite lightweight including a 0.48 mm wheel that with supports weighs in at about 100 grams.

If you want to get into having a project car, we’d suggest something more modest. Even if you want to 3D print a titanium part for your ride, we’d still start a little smaller.

Nissan Gives Up Root Shell Thanks To Hacked USB Drive

January 30, 2021 by Tom Nardi 46 Comments

For the impatient Nissan owners who may be joining us from Google, a hacker by the name of [ea] has figured out how to get a root shell on the Bosch LCN2kai head unit of their 2015 Xterra, and it looks like the process should be the same for other vehicles in the Nissan family such as the Rogue, Sentra, Altima, and Frontier. If you want to play along at home, all you have to do is write the provided image to a USB flash drive and insert it.

Now for those of us who are a more interested in how this whole process works, [ea] was kind of enough to provide a very detailed account of how the exploit was discovered. Starting with getting a spare Linux-powered head unit out of a crashed Xterra to experiment with, the write-up takes the reader through each discovery and privilege escalation that ultimately leads to the development of a non-invasive hack that doesn’t require the user to pull their whole dashboard apart to run.

The early stages of the process will look familiar to anyone who’s messed with embedded Linux hacking. The first step was to locate the board’s serial port and connect it to the computer. From there, [ea] was able to change the kernel parameters in the bootloader to spawn an interactive shell. To make things a little easier, the boot scripts were then modified so the system would start up an SSH server accessible over a USB Ethernet adapter. With full access to the system, the search for exploits could begin.

A simple script on the flash drive enables the SSH server.

After some poking, [ea] discovered the script designed to mount USB storage devices had a potential flaw in it. The script was written in such a way that the filesystem label of the device would be used to create the mount point, but there were no checks in place to prevent a directory traversal attack. By crafting a label that read ../../usr/bin/ and placing a Bash script on the drive, it’s possible to run arbitrary commands on the head unit. The provided script permanently adds SSHd to the startup process, so when the system reboots, you’ll be able to log in and explore.

So what does [ea] want to do with this new-found exploit? It looks like the goal is to eventually come up with some custom programs that extend the functionality of the in-dash Linux system. As it seems like these “infotainment” systems are now an inescapable feature of modern automobiles, we’re certainly excited to see projects that aim to keep them under the consumer’s control.

Sony’s Electric Car Now Road Testing In Austria

January 27, 2021 by Lewin Day 73 Comments

The Consumer Electronics Show was not typically a place for concept cars, and Sony aren’t known as a major automaker. However, times change, and the electric transport revolution has changed much. At the famous trade show, Sony shocked many by revealing its Vision-S concept — a running, driving, prototype electric car.

Far from a simple mockup to show off in-car entertainment or new fancy cameras, Sony’s entry into the automotive world is surprisingly complete. Recently, the Japanese tech giant has been spotted testing the vehicle on the road in Austria, raising questions about the future of the project. Let’s dive in to what Sony has shown off, and what it means for the potential of the Vision-S.

Continue reading “Sony’s Electric Car Now Road Testing In Austria” →

Pandemic Chip Shortages Are Shutting Down Automotive Production

January 18, 2021 by Lewin Day 66 Comments

Once upon a time, the automobile was a mostly mechanical beast, but no longer. Advanced electronics have weaved their way into the modern car, from engine to infotainment and climate control to the buttons now sprinkled throughout the passenger cabin. The gains in amenity and efficiency can’t be sniffed at, but it leaves manufacturers reliant on semiconductor suppliers to get cars out the door. Over the past year, it’s become much more complicated — with many automakers having to slow production in the face of integrated circuit shortages that can be traced back to Spring of 2020. Continue reading “Pandemic Chip Shortages Are Shutting Down Automotive Production” →