[Ovmsdev] Trying to get a new car in, CRTD, CANbus and all

Julien “JaXX” Banchet jaxx at jaxx.org
Tue Jul 16 01:21:03 HKT 2019

> On 15 Jul 2019, at 18:52, Craig Leres <leres at xse.com> wrote:
> I don't know anything about VW network buses but with GM there are usually two buses (OBD-II up through 2014 anyway). All models have a high speed can on pins 14 and 6 of the diagnostic connector. Newer models have a low speed, single wire can bus on pin 1. Older use J1850/Class 2 PWM on pin 2. The high speed bus has mostly engine, brake and related. Doors, hvac, infotainment are on the low speed bus. Single wire can and J1850 appear to be unique to GM.
> I would start by figuring out where the other buses are in your new car.

Yeah, I know some metrics seem to be carried over the classic CAN bus (battery level is often tagged "Hybrid Battery Pack something” because of hybrids in the line), Pin 1 is activated to +12 on ignition, and K-Line is pulled down eventually by diagnostic tools to trigger “gateway” accessing, but well, still in early discovery.

There is lots of business going around OBD dongles for diagnostics that allow some configuration of various organs of the car (Coding / Long Coding / Adaptations, they have a broad new vocabulary to learn), I probably won’t get active help because of fear of competition (heck, à 100€ device that does it all, without licensing or credit purchase, that’s fresh!)

But well, worst case, I’ll reverse engineer the whole thing, since I’m moving to a new place with an enormous and electrified garage ;-) but that’ll be for autumn.

We’ll get there, I wan’t this to work !

> 		Craig

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