MoTeC Global Forum

I can't get my C125 to work with my M84. When first purchased it worked but now it is fully installed there is no comms. The C125 lights up and I have the C125 voltage but nothing from the M84. I checked the ohm resistance between CAN Hi & CAN Lo at each end of the bus and it is 100 ohm both ends. Any ideas?

Configuration change? Broken wiring?

What changed since it was working?

My guess -- you changed what CAN bus on the C125 was used for the M84, and need to change the configuration to match the final wiring.

Where are you located -- can your MoTeC dealer help you?

Hi Tom,

As mentioned by David, check to make sure that you have the correct CAN Bus being used with the C125, the default setting is CAN2 (Pins 26 & 27).

Can you also connect to the Dash and go to Monitor Channels (F3 Key) and look or the channel named "Comms CAN 1 Diag" and report on the value that is shown.

Thanks David and Stephen, I will check both on the weekend

Stephen / David
The CAN wiring is B23 and B24 as per the wiring diagram on pg78 of the manual. B25 and B26 are used on the lambda sensors. The CAN setup is Dash/Logger CAN Address=232, VCS/PDM CAN Address=0, SLM CAN Address=0, PLM CAN Address=0, not sure if this helps, hopefully this will give the next step/idea
I have screen dumps of each page if required

Tom,

You are missing some important details:

- We wanted to verify that your CAN bus connection was to pins 26 & 27 (CAN2 - the defualt) or pins 18 & 19 (CAN1) of the C125 connector.

- The C125 Configuration needs to be verified as to which CAN bus used for the "Motec M84" template. Use C125 Dash Manager->Connections->Communications... then click the CAN1 or CAN2 tab to see which one has "Motec M84".

- With the Dash & M84 powered up, use the M84 Dash Manager->Online->Monitor Channels... to check the status of the "Comms CAN 1 Diag" channel. Report the value that is shown.

- Tell us where you are located -- perhaps we can work with you directly to resolve this.

David
Thanks again for your reply
- The CAN is connected to the C125 by wires 18 and 19
- CAN 2 is loaded with the Motec M84 template on the C125
- On the M84 Comms CAN 1 Diag is 512
- I live in Melbourne Australia
Thanks
Tom

OK, so the solution is clear now.

Use the C125 Dash Manager, open your configuration, then open the Communications Setup window by using Connections->Communications... Click the CAN 2 tab, select the Motec M84 template and click the "Remove" button. Now click the CAN 1 tab, and use the Select... button to choose the Motec M84 template.

Send this configuration to your C125, and verify that Comms CAN 1 Diag is not 0, and you are receiving the M84 data.

Just to add one small step to Davids procedure, after removing the M84 template from CAN2 you should 'OK' the communications window and then go back in (Connections>Communications) and add the M84 template to CAN1.

The reason for this is Dash Manager doesn't validate the configuration until you close the window. If you don't exit the window before adding the template to the other CAN bus you will get channel conflict errors.

Thanks David and Adrian
I followed the steps, deleted Motec M84 from CAN 2, closed the window, then added Motec M84 to CAN 1
The C125 now is receiving from the M84, I haven't started the engine yet but the numbers look good
The only issue is the Comms CAN 1 Diag = 0, is this a problem, should it be 1 as above
Thanks again
Tom