Re: Firmware Dane Elec So Easy
Nelson Suggs
The Audi Hybrid's have a really spicy alternator shaped motor that provides launch assist and regen breaking all in a small low voltage package. The following documents trying to wake this up for non-audi uses, like goofy electric vehicles.
When I started the e-torque reverse engineering it seemed to be the most widely-available option in terms of 'low voltage' hybrid motors. These motors are great for 'large but not enormous' robots, go-karts and the like. Audi ended up also embracing the mild-hybrid approach, but with a lot less publicity. Lets take a look at the 48V Audi options and try and wake them up. For the sake of simplicity, and instead of writing motor-generator, I'm opting to call these things an altermotor, or alternator-motor.
These photos tell us a lot. We have our familiar rear cover from Continental and a different power input location. Its possible that this vehicle floats the hybrid bus off the frame and cant use chassis ground. Otherwise this is looking really familiar, given that this has two power terminals, coolant plugs and a communications connector, we are likely looking at another 3phase integrated motor inverter assembly! We also get a sneak peak at the communications connector from the eBay vendor. Different assembly vs the 'e-torque' branded ones, and fewer pins. 5 Pins is 'interesting' we could literally have +12, return CAN-H CAN-L and some kind of wake-up pin?
There is a basic vehicle overview here, which just shows the belt alternator starter-generator tied to a mechanically small 48V hybrid pack and what appears to be a 12v pack way in the back of the vehicle. This is a little odd but the 'engine start' is accomplished mostly with the belt starter so the 12V loads are mostly auxiliary.
I was able to find some dubious copies of parts of the Audi Q8 'workshop manual'. For the sake of ignorance I'm listing them here, these should be available under Massachusetts automotive right to repair. I contacted Audi to ask permission to post diagrams for research and they ignored answering the question.
We don't really get a lot of technical details out of these workshop manuals, its not like they call out the CAN messages. A majority of the documentation is on how to remove / install hardware. Its pretty apparent that the stack up and belt wraparound make things somewhat annoying to remove / install. We do learn about some kind of Audi 'vehicle diagnostic tester', which may be useful to find a 3rd party one of these.
Lets do some digging to see if anyone has documented these procedures online. This is a relatively new car and the Audi crowd isn't really known for DIY repairs, but we may get lucky. Technical Service Bulletins also can provide a bit of a sneak peak if these have issues overtime. The audi forums were really interesting, with everything ranging from late December 2022 to early 2023 sourcing issues and then a claim that there's a firmware issue in the alternator that causes them to explode, and an associated firmware update to fix this? Wait is there a firmware package for this motor hiding online somewhere? Forum posts are here [link] and here [link]
Here's the TSB [link] and local copy [link]. Lets see what we can find. I wonder if I can argue 'right to repair give me your firmware'. The first bit we learn is all of the Audi car models that have this same part, it turns out there are a lot! The same part looks to be compatible with a lot of vehicles so eBay searches can now span a lot more vehicle models. Lets update the chart above to display this.
I genuinely wonder how terrible it will be to try and get access to Audi firmware or firmware loading tools. Would these technically *have* to be available under right to repair?
Continuing on, I found an interesting news posting [link] titled 'Audi VW Mild Hybrid disaster', sounds like a relevant read. Its unfortunately mostly sarcastic humor and lacks any details. They call out on IGBT failures? this sounds wrong, as there is no reason to use an IGBT on a low voltage application. An updated post [link] shows some of the issues with the battery module (high quiescent current which bricks the pack fairly quickly). I did come across ross-tech [link], who seems to supply 3rd party diagnostic software for Audi / VW hardware. May have to give them a call and find someone to chat with about this motor, it looks like this [link] may be a good first step, assuming their software can talk to a vehicle with *a lot* of can bus parts disconnected. Digging through their software manual [from here] [local copy] we find a pretty cool tool that can show diagnostic values and even set parameters. Its unclear if its talking to a body control unit or like some kind of master unit / if it knows. The plot is to get up to speed with their software manual then call during a week-day to ask pertinent questions. Their gadget is 200$ and acts as the hardware key for their software, who knows there may be an academic discount. There appear to be a lot of ebay-clones but its not clear if these are software-compatible. While I do not have the adapter yet, I was curious to check if the supporting files for the software had some notes.
While we're comparing the motor, here's a comparison between an image from Damien Macguire 's audi motor vs my jeep e-torque motor, again not really a huge difference but we do see a possibly different bus-capacitor? The Jeep variant has a 63V 470uF capacitor, while the Audi has a 330uF cap. Given that they are the same size, maybe the Audi version is a higher ripple current rating? Generally with a fixed volume of capacitor you trade off between capacity and ripple current, as to attain a higher capacitance you need more surface area and all things equal to do that you use a thinner electrode so you can fit in more volume of electrode.
Googling that part number doesn't give us anything useful, but the a2c02407001 does link us to, a TikTok hosted ondouyin.com [link]. Oh boy is this worth it? After some sleuthing later I was able to uncover the video:
Here's a copy of the video [link]
It looks like this guy is trying to debug an actual hybrid motor failure, but the more interesting part is *what tool he is using* to talk to the car. From some short screenshots we find that he's using "Off board Diagnostic Information Service 9.0.1 (confidentiality level: confidential)" The diagnostics are all in Chinese (Mandarin from the looks of it), so I'd need to find an English version, or whatever settings are required if there's a language selection.
Some googling later, we find that off board diagnostic information service is called ODIS. I did find some kinda installer video [link] which looks remarkably dubious. I'd like to pay for software if its actually useful, but I couldn't find a way to do that directly from Audi. eBay it is. As i'm paying for software, its not piracy, although I doubt a full copy is only 20$ from Audi.
It looks like peak can adapters *should* work with this tool from this form post [link]. I have a loaner Peak Can USB Adapter IPEH-002021 [Digikey link]. At 260$ its a pricey adapter. There is an opto-isolated version, IPEH-002022, which i'd love to grab if it weren't an extra 50$.
With the motor now in-hand, we can confirm some of the info dug up before, its very very similar to the 48V E-torque. The major noticeable exceptions are the power lugs, the communications connector, the mechanical mount points and the coolant connection points. This seems like a fairly significant difference, but realistically the motor characteristics are defined by the rotor and the stator.
When digging up the motor wiring I unearthed this treasure, what appears to be a partial pin out of the motor communications connector. We learn that Terminal 30 is actually (+12v), terminal 31 is (12v return), pin 3 is (CAN+), pin 4 is (CAN-) and finally pin 6 is PWM. Is PWM important? Its actually really helpful to determine if we successfully 'woke up' the motor. From what I've read the motor commands a PWM to an auxiliary coolant pump to throttle temperature, ideally when the motor is awake we should see it commanding a simple PWM to the coolant pump. A link to the file this came from is available here [link] [local copy]. An NHTSA document also details some interesting bits of the hybrid subsystems here [link] [local copy]
The NHTSA "2019 Audi A8 Electrics and Electronics" self study program is a curious one. Its a short service training manual, but it has some interesting details. I did love the "don't publish me", but its on a national government safety website so this is safe to ignore.
The vehicle can run off the alternator-motor with the engine off for 40 seconds. This somewhat changes the game here, as I was under the impression that the altermotor is tied to the engine via a belt. How can this run decoupled? Is there a one way bearing somewhere, so the motor can provide power with the engine disabled? The more I think about this sentence the less sense t makes. The altermotor would have to spin the engine sans-fuel to get power to the wheels. Am I missing something, lets keep reading maybe this is spelled out more. A normal car at 70mph can 'coast' for 40 seconds when the engine stalls, maybe they are just claiming that as a feature? The car can roll is a feature?
Continuing on, we learn that the 48V positive is called "Terminal 40" and the 48V negative is called "Terminal 41", this is actually helpful as the hybrid jeeps just label things "batt+ regardless of 48v or 12v and its terrible. We do get a really nice cutaway image of the front of the vehicle. As mentioned earlier we get a conventional 12v starter motor, awkwardly buried inside the engine, and a 48v altermotor that appears to be tied directly to the engine belt loop. This vehicle's electrical system is so awkward, you have to maintain a 12v battery and 12v system for compatibility with older systems, and also maintain a 48v battery and 48v system for a hybrid duty cycle. The hybrid battery seems *incredibly undersized* for the altermotor.