How to Set Up a MoTeC C125 Dash Using a Link ECU
Custom CAN Messaging, Data Channels, and CAN IDs Made Simple
If you're running a MoTeC C125/C127 dash and want to feed it custom data from a Link ECU, the key is understanding CAN stream setup, data mapping, and why we choose custom CAN IDs for flexibility and future-proofing. In this guide, Ill walk you through how to:
- Set up a Link ECU to transmit data via CAN.
- Configure the MoTeC C125 to receive that data.
- Choose smart CAN IDs that avoid factory protocol conflicts.
Step 1: Setup Link ECU to Transmit Data via CAN
In Links PCLink software:
1. Go to ECU Controls > CAN Setup > Streams.
2. Choose a free stream like Transmit Generic Dash or a User Stream.
3. Set the bit rate to match your MoTeC (we're using 500k but typically 1Mbit/s).
4. Set CAN ID (decimal) to something high and unique were using 1000 (Hex 0x3E8).
Tip: Each CAN ID acts like a labeled container your dash listens to.
Step 2: Add a Second Stream for Compound Data (if you want to send more than one message in a single stream).
Use another stream (e.g., User Stream 6) with a different CAN ID like 1101. This keeps data types separated and organized.
Step 3: Configure MoTeC C125 to Receive Link Data
In Dash Manager:
1. Go to Communications > CAN Setup.
2. Add a new CAN section (e.g., Link ECU CAN).
3. Set the Rate to match the Link ECUs setting (e.g., 1Mbit/s).
4. Under Received Channels, manually assign the data you want to receive that isn't already checked off (Engine RPM, MAP, Throttle Pos, etc.)
You can see the "Alignment:" is Word Swap that would signify endianness being Least significant or Little endian Motec's wordage. If it was Big Endian it would read "normal".
Step 4: Sending compound messages through one CAN ID
In the image below you can see we send multiple item's that aren't found in Links "transmit generic dash" file. such as: Coolant pressure, Closed Loop fuel corrections, Boost aim/target, Lambda aim to name a few.
I wont go into detail on how that's done because this post would get long fast. Here's a few pictures of what the received message looks like.
each block of three messages have a unique ID starting from 0 - 16 with the base ID of "1100" and within that message we would have the first 3 items be ID 0000 and the next be ID 0001 and so on and so forth. Lastly once we're done with the data we want to receive and or transmit we need to setup the display to show what data we want to view on the dash display.
You can choose whatever you like, we even can display PDM data from output currents, output status, faults with an output and much more.
Here's what it should look like once it's all finished up.
First we build the dash display loom, Include every possible input/output including GPS, Digital Inputs, Both CAN 1/2 and the ethernet communication cable. Which can be purchased from us. https://ae-race.com/products/motec-c125-c127-dash-display-wiring-loom
There's so much more that this dash is capable of for instance it can be used for inputs/outputs. Logging up to 120mb using Motec i2 analysis software.
Custom shift lights fully user configurable, Warning light's for engine temperature, low oil pressure, over boost, Lean air/fuel condition while in boost the sky's the limit.
All of this data can be sent to the ecu for General purpose rev limiters as well.
Say we're running a MonsoonX ecu and we're limited to the 4 x analog voltage sensor inputs. We could use the dash as a data hub to send over up to 10 more analog inputs (4 of them being low resolution inputs) and 3 more speed inputs either VR or hall effect.
This dash is a lot to take in and not cheap, yet it's so much more capable than anything else on the market for being consumer grade.
Want a Prebuilt Link-to-MoTeC Template?
I'm working on releasing downloadable CAN stream templates for:
- C125 / C127
- Link G4X/G5 ecu with custom streams.
- Alarms/message's
- Custom 2D/3D table setup
- Page display / next line via CAN keypad button presses
- Fuel level setup with fuel% remaining display.
👉 Email Tuning@ae-race(dot)com or DM me on Instagram [@aerace_fab].
Thanks for reading and hopefully learning.