Note: I drafted this post in February and somehow never published it.

Github user SMCinc posted his research on ZOE’s TPMS system in CanZE’s issue tracker.

The proper TPMS sensors can be coaxed to transmit their ID using 125 kHz activation tool. Those tools are cheaper than a decent dongle. Search for “EL 50448”.

The transmission of the sensor can be received by a cheap DVB-T USB Stick with RTL2832 chipset and the rtl_433 software from Github and a Zadig driver (latter only if on Windows). It runs fine on a Raspberry Pi.

rtl_433 -f 434000000 -R 123

Here is example output

https://i2.wp.com/user-images.githubusercontent.com/55346351/74090534-b2093680-4aac-11ea-9261-9887df32b3a6.png?w=918&ssl=1

The ID of the the sensor here is A3FFDAD which should be entered in CanZE as

  1. looks like we have solidly past 6200 users. A user is defined as having the app installed on at least one device running under it’s account, for somewhere in the last month. It is not a run metric.
  2. Guess what I have on my driveway now on loan for a full week. Watch this space……..
  3. I have understood that most TPMS functions are available on the ZE50 natively. Would it be prudent to disable them for a ZE50? Or asked differently, is there anything a ZE50 needs regarding TPMS that is NOT already natively in the car and that we offer today for the earlier models?

This morning I received a message from user @Minibiti reporting success on the ZE50 test code. This indicates our route to enabling CanZE for the ZE50 is probably solid. In aeronautical terms: the test flight was a success and we will now open up the envelope. Apart from a very small change that needs to be tested, it could be mostly boring table conversion work. Thank you Minibiti!

Minutes ago, I released a new beta. It contains, next to the usual array of small fixes, very limited proof-of-concept test-code for the ZE50. Select ZE50 in settings, ensure ISOTP fields is on, return to main, swipe to experimental and tap ZE50. Under the 4 meaningless lines it just might display the accelerator pedal position in %.

Please note that substantial changes in several places had to be made to make this work, and I do not have a ZE50 at my disposal to test. In other words, this is completely testing in the blind and anyone who has ever made any software knows where that leads to.

I’d appreciate feedback of course, if anything with debug files etc.

The good news is that as soon as this works, getting the current functionality of CanZE migrated to the ZE50 is straightforward.

A friend of mine received his ZE50 last week. Only a few days later we had a successful “CANbus sniffer session”. As I indicated in another post it seems the E-bus of the car, which in the past was wired directly to the OBD2 (SAE-J1962) connector, is now firewalled. And indeed, in the list of ECU’s of the ZE50 there is what is called a “Secure Gateway”.

First indications are the gateway needs to be mildly coaxed into letting us through, but for non-evasive stuff like CanZE does, there is no cryptographic authentication involved.

There are a LOT of new boxes in the ZE50. Some have 11 bit addresses, some 29 bits, and some seem to be able to use both. Let’s call that “interesting”.

So where are we now? Well, we have a few reasonable assumptions now. At the moment, I am making minor changes to the CanSee dongle so it supports 29 bits addressing and it’s internal table of ECU’s contains the new boxes. That is reasonably straightforward and almost done.

Next, I will add a simple screen to the experimental section of CanZE and see if we can make that work flawlessly. Just a few fields. To test that it will require another round trip to my buddy who will kindly let me plug in my gear into his car. This is a crucial step. If this goes as expected, the remainder is just work.

We need to upgrade the driver for the ELM dongles to enable 29 bit mode, and finally we need to go over each and every field to see if we can use the old definitions or need to adjust.

So, there is a plan now, there is decent logging data, and fairly good field definitions. But first I need to get rid of the flu 🙁

There is confusion about how to obtain the IDs of TPMS sensors. goingelectric.de user E-Gerd-21 figured it out in this post, thank you! TL:DR Use only the last 6 hex characters of the IDs that came with the valves. Those are usually 8 characters. If the first of those 6 is between 0 and 7, add 8 (hexadecimal, so i.e. if it was 3, add 8 becomes B). In other words, the first character should always be between 8 and F. This bit manipulation will be added in the next release.

Since there are different types of sensors, some are not compatible with ZOE’s TPMS system at all, and I read somewhere success entering the first 6 characters of the supplied ID instead. In other words, your mileage may vary. Of course the most safe option is to have the sensors installed once by the dealer and then read them with CanZE.

Finally, in the next release there will be a helper function swapping the front and back axles, simplyfying wheel swaps.