Motec M84 CAN Bus Settings

Discussions on CAN mapping for ECUs, sensors, PDMs, and more.
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camsmyth
Posts: 1
Joined: Tue Aug 10, 2021 10:07 am

Motec M84 CAN Bus Settings

Post by camsmyth »

Hopefully this is helpful for someone else. I tried to get my Motec M84 talking to my racecapture a few years ago and I just could not get it - there is virtually no info available but I stumbled across a few things recently that helped me piece it together (I actually just integrated and Emtron in another car with a racecapture which motivated me to find a solution for the M84).

So here it is:
- In Motec Ecu Manager Software navigate to Adjust->General Setup->Communications->CAN Setup
- set VCS/PDM CAN Address to 280
- make sure you terminate the M84 end with a 120 ohm resistor (literally just wire one between the 2 CAN wires where they come out of the ECU)

In Racecapture the common settings are:
Baud: 1M
Sub ID: disabled
Mask: 0
CAN Bus: whichever one you have wired the Motec to
Signed
Big Endian
Bit Mode: No

Channels:

Ground Speed, address: 280, byte: 2, length:2, multiply by 1, divide by 10, +0
RPM, address: 280, byte: 4, length: 2, multiply by 1, divide by 1, +0
Gear, address: 280, byte: 6, length: 2, multiply by 1, divide by 10, +0 (I did not use)
Efficiency, address: 281, byte: 2, length: 2, multiply by 1, divide by 10, +0 (Not sure what this actually is!)
Throttle Pos, address: 281, byte: 4, length: 2, multiply by 1, divide by 10, +0
Engine Temp, address: 281, byte: 6, length: 2, multiply by 1, divide by 10, +0
Air Temp, address: 282, byte: 2, length: 2, multiply by 1, divide by 10, +0
Oil Pressure, address: 282, byte: 4, length: 2, multiply by 1, divide by 10, +0
Fuel Pressure, , address: 282, byte: 6, length: 2, multiply by 1, divide by 10, +0
User 1, address: 283, byte: 2, length: 2, multiply by 1, divide by 10, +0
User 2, address: 283, byte: 4, length: 2, multiply by 1, divide by 10, +0 (I have oil temp on this channel)

brentp
Site Admin
Posts: 6274
Joined: Wed Jan 24, 2007 6:36 am

Re: Motec M84 CAN Bus Settings

Post by brentp »

This is great, thank you for the update.

We can get this CAN mapping imported into our presets; could you email us a saved copy of your RaceCapture configuration file?
Brent Picasso
CEO and Founder, Autosport Labs
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