Discussion and questions related to the course CAN Bus Communications Decoded
I just watched the recent webinar that Andre presented where he went through (in a lot of detail) connecting a MoTeC M150 ECU to an ECUMaster PMU. I've done the same thing and I have all of it working with an Eaton CAN keypad, AiM MXS dash, and a ECUMaster steering wheel card. I've got buttons and rotary switches working, etc. I get data from the M150 and I'm able to send inputs to it via CAN.
I get a diagnostic from the M150 complaining about PDM errors. I'm surmising that the M150 is expecting to talk with a MoTeC PDM and there's a protocol not being met by the ECUMaster PMU. I'm wondering if anybody else has encountered and fixed this problem? It would be nice not to always have that one red indicator when I'm in M1 Tune.
What exactly is the diagnositc error you are seeing? I find there are some error (F3 diagnostics) that you just can't get to go away, without building your own M1 package to eliminate the source. So while annoying, it may just be the way it is.
Yes, it's an F3 diagnostic. I'll power the car up and get a picture of the error.
Time 0:00.500: PDM Diagnostic = Invalid CAN Configuration
As I mentioned above, both devices are talking with each other without any other apparent issue.
So what are the values of the "PDM CAN Bus" parameter and the "PDM CAN ID Base" parameter?
The PDM Receive code is inside a binary module in M1 Build so I don't have any insight into what it's expecting and what will generate the Invalid CAN Configuration. But you're probably right it's looking for some normal MoTeC PDM transmission or response that it doesn't see.
Thanks David. If I knew what the M150 was expecting, I'm sure I could get the PMU to send it. Sounds like I'll need to live with that single error. Thanks for looking at this!
Is your PDM sending any of the 6 messages (CAN ID Base through CAN ID Base+5) described in the PDM manual found here:
At a minimum I think you should send to CAN ID Base, the compound ID 3, which is a global status and should be pretty easy to generate.
Do you mean the CAN Output messages on page 46? No, but I'm sure I can. I'll give that a try, starting with the minimum message you suggest.
Yes, that's the standard PDM output. I could see how the M1 Diagnostics could report "Invalid CAN Configuration" if it did not see the message at the configured base ID on the configured CAN bus. I would expect it would report message timeout if it didn't receive some messages on the other CAN IDs.
Makes sense to me. I'm headed to Sebring for a weekend event. I work on this next when I get back to the shop, and report back.
David, that worked! Diagnostic is off, and the ECU thinks it's talking to a MoTeC PDM16. Thanks for the help!