DSORDA Posted July 14, 2021 Report Share Posted July 14, 2021 Hey guys, Having a wee hiccup with my CAN settings. I swear I just need to sit a CAN course and get my head around this stuff! Previous setup with Link Fury, Motec PDM and Motec Keypad, all working faultlessly on CAN2. Was running an older style AIM Strada dash on CAN1. Now, I have upgraded to a Motec C127 dash, and added a HV Electronics CAN EGT box to CAN2. Nothing on CAN1 anymore. I have uploaded the generic dash stream so I can change around a few of the things I want to display on the C127, and at the moment, everything displays as it should, and the EGT readings are all coming through to the Fury and reading correctly. The odd issue I am having, is when I watch the runtime values, about 2-5minutes after powerup, I will get a "Form Error" alert and after about the same time again, some subsequent errors. Have I simply messed up a CAN ID for the dash or HV EGT? I have tried running the generic dash setting on Channel 1, no difference. Also tried matching the transmit rates of channels 1&3 to 50hz for the different streams and no difference. And finally, tried setting the generic dash frames to be MS first byte order first, and although it put all my dash display readings up the wack, still didn't remove the form error. What am I missing here? I feel like it is right in front of me and something simple. CAN settings attached. Any help would be greatly appreciated as always! CAN Form error.pclr Quote Link to comment Share on other sites More sharing options...
Adamw Posted July 14, 2021 Report Share Posted July 14, 2021 Those errors are higher level errors that come from the CAN controller. Generally not set-up, more like a bus problem or some device is not honoring the CAN rules. With everything shut off do you measure 120ohm accros the CAN wires? Can you unplug the egt and PDM and see if the errors come back with them unpluged (need to power cycle the ECU for the errors to clear). Quote Link to comment Share on other sites More sharing options...
DSORDA Posted July 14, 2021 Author Report Share Posted July 14, 2021 Thanks for the suggestions Adam. I went ahead and unplugged just the EGT box, powered everything up and no errors would reappear. So that's a start. Will measure resistance and report back Quote Link to comment Share on other sites More sharing options...
Adamw Posted July 15, 2021 Report Share Posted July 15, 2021 Probably nothing to worry about if everything keeps working, but one thing you could try is setting up some receive streams in either the dash or ECU for the other two EGT messages that you arent using - it may be that it is throwing the errors because no device is acknowledging those messages. It shouldnt do that but some CAN controllers have some odd hardcoded behaviour that doesnt always follow the standards. The TCE4 broadcasts 3 ID's, 600,601 & 602. You are only receiving 600 in to the ecu. So just try a blank receive for 601 & 602 - these messages will then be acknowledged. Quote Link to comment Share on other sites More sharing options...
DSORDA Posted July 20, 2021 Author Report Share Posted July 20, 2021 Tried receiving messages 601 and 602, but still had the same errors. I checked the bus resistance at the plug going into the TCE4 (with everything shutdown) and it was only reading 100.5ohm. Potential issue there? Quote Link to comment Share on other sites More sharing options...
Adamw Posted July 20, 2021 Report Share Posted July 20, 2021 No that should be ok. 120 is from the Bosch standard but I see Motec always say 100ohm in their documentation so either seems to work fine. I think you will just have to live with it - provided it is not preventing anything from communicating. It would take someone fairly experienced with a scope to see what is the cause. Im not sure even I know enough about the error checking side of CAN - usually all this logic is built in to the CAN controller IC and the end user never has to know anything about it. Quote Link to comment Share on other sites More sharing options...
DSORDA Posted July 21, 2021 Author Report Share Posted July 21, 2021 That's fine Adam, I can appreciate that. Just wanted to rule out it wasn't something as simple as a setting that I had mucked up. Everything reads as it should so I'll leave it at that and report back if something fishy does pop it's head up later on down the track. Thanks for the help as always Adam! Legend Quote Link to comment Share on other sites More sharing options...
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