supersnoop
Tesla Roadster #334
From the folks who sell the OVMS module:
https://www.fasttech.com/products/1080/10000001/1000400-ovms-data-cable-for-tesla-roadster-1-x-2-x
spaceballs
Member
Pretty sure it's this http://www.mouser.com/Search/ProductDetail.aspx?R=173851-2virtualkey57100000virtualkey571-173851-2
Pins for connector (again not 100% sure) http://www.mouser.com/Search/ProductDetail.aspx?R=173630-1virtualkey57100000virtualkey571-173630-1
In the roadster, there are four CAN buses. CAN0 on the right, and CAN3 on the left. Pinouts are H at the top, L at the bottom. As indicated, there are +12V permanent and GND pins available two. We use CAN0 (as indicated) for our work on the roadster, as that is the bus with the instrument stuff on it.
Plus is
TE Connectivity / AMP 173851-2
and matching pins are
173631-1
Socket is
TE Connectivity / AMP 174933-1
and matching pins are
173645-1
Mark, What kind of traffic goes over each of the CAN buses? Why is there a need for four separate CAN buses? Can you see all the traffic that is going between the ESS and the PEM from the CAN buses that are available in the diagnostic connector? Thanks.
It is common practice in modern automobiles to separate the different parts of the car out from each other by putting them on different CAN buses.
For example, on the roadster, the buses are split:
* Power Train (PEM, body control, parking lock, gear selector, ABS)
* Energy Storage (HVAC, Battery x13)
* Driver Feedback aka Instrumentation (Instrument Cluster, Touchscreen, TPMS)
The idea is that a faulty component on the Driver Feedback bus shouldn't affect the power train (for example). Also, the bandwidth of each bus is kept to just what is required by the modules on that bus.
All three buses go into the Vehicle Management System (VMS). That does have some capabilities for reflecting information on one bus onto another, but in general each bus has its own unique messages and information.
Yes, that connector provides access to all the above three buses.
Thanks for the detailed explanation. Do you know what kind of micro-controller is in the VMS? I didn't realize that the brains of the roadster was outside of the PEM.
Someone mentioned it recently, somewhere on the interwebs, but I can't remember who/what/where. I seem to remember them saying it was a 4 CAN bus ST microcontroller, but not certain.
wiztecy
Active Member
Its an NXP LPC2294 chip which is an Arm 7 based microcontroller (with 4 CAN controllers):
http://www.nxp.com/documents/data_sheet/LPC2292_2294.pdf
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Design of the Model S is slightly different, but based on the same model. Multiple buses. In the Model S, the instrumentation uses ethernet, and a CAN-to-ethernet gateway is used to bridge the two.
matt_in_ca
Member
What do you want to adapt it to? The Roadster's OBDII port isn't "standard", other than the physical connector and the +12v power it provides.
See: New OVMS and the other base thread that it references.
Why bother? There is nothing much of interest on that connector.
The K-line is connected to TPMS. Any standard OBDII bluetooth/wifi/usb ELM327/STN1110 should be able to read that.
The CAN bus is connected to VMS, supposedly at 1MHz. OBDII dongles won't handle that speed; you'll need a dedicated USB-CAN adaptor. I haven't seen any documents on what is on that bus (if anything).
You won't find any OBDII standard PIDs there.
ShawnA
Supporting Member
Hi Mark,
Is the picture of your fingers and the OBD connector removed from its connection to the VMS?
Thank you, Shawn
PS - Still working with the OBD2 and TPMS programming for the Roadsters serial 501 and up.
Is the picture of your fingers and the OBD connector removed from its connection to the VMS?
Thank you, Shawn
PS - Still working with the OBD2 and TPMS programming for the Roadsters serial 501 and up.
That picture (if it's the one I'm thinking of) is of the Roadster's "Diagnostic port". It's normally just hanging there, unconnected, under the passenger-side of the dash. It's intended for the service folks to access the car's internal CAN bus system. Nothing standard about what happens there, hence the OVMS module to receive and interpret the traffic.
The OBDII port is on the driver's side, mounted against the center console under the dash. Standard physical connector and mounting location, but not much to gather by plugging into it, or at least conflicting information about the signals supposedly present vs folks actually doing something with them. Tesla included it because the regulatory framework at the time required the connector. So they put one in.
If you can raise some sort of conscious response from the OBDII port (e.g. on the K-line), you will probably be the first. Please let us know!
The OBDII port is on the driver's side, mounted against the center console under the dash. Standard physical connector and mounting location, but not much to gather by plugging into it, or at least conflicting information about the signals supposedly present vs folks actually doing something with them. Tesla included it because the regulatory framework at the time required the connector. So they put one in.
If you can raise some sort of conscious response from the OBDII port (e.g. on the K-line), you will probably be the first. Please let us know!
ShawnA
Supporting Member
Hi Greg,
Thank you. I have been working with the one at the US driver's right knee location.
I have heard about the one on the passenger side but I have not looked for it or done anything with it.
I am sure it is the OBD2 on the driver's side that uses the K-line for TPMS input, but I have yet to get it to accept my inputs...
Thanks again, Shawn
Thank you. I have been working with the one at the US driver's right knee location.
I have heard about the one on the passenger side but I have not looked for it or done anything with it.
I am sure it is the OBD2 on the driver's side that uses the K-line for TPMS input, but I have yet to get it to accept my inputs...
Thanks again, Shawn
matt_in_ca
Member
I would like to use a pay-as-you-drive insurance service, but that requires plugging in an OBD-II dongle
