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Connecting to Bosch DDU7 dash over CAN

Richard Luciano

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I have a Link G4 extreme (serial 12xxx). I have a Bosch M4 motorsports ABS unit and Bosch DDU7 dash. I have connected the DDU7 and M4 with the Link G4 by the CAN bus connector. The DDU7 sees the data from the M4. But I have not been able to get ECU data to the DDU7.


Here is the Link configuration. It is the generic dash setup:


I have confirmed that the DDU7 is communicating with the M4 ABS and the yaw sensor over CAN. They are communicating at 1 Mbps. 

Here is the DDU7 CAN input setup page. I believe 3E8 hex is 1000. For RPM I set the multiplexer value to 0. I have tried with the extended box checked and unchecked, it does not work either way. Do I need to change the endian settings? Or what do I need to change?

RaceCon copy


Hoping someone can help.


Richard Luciano

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Here are a few things:

- The CAN Id is correct 1000 (0x3E8)

- The CAN Id is NOT extended

- The data is sent in frames of 8 bytes.

- The first byte (byte 0) indicates what data is in the frames.  This is what is referred to as the compound Id.  When byte 0 is zero then it indicates the frame contains RPM, MAP, MGP.  When byte 0 is 1 the frame contains BAP, TP, Injector Duty Cycle

- The multiplexer field specifies the compound Id.  While technically it is 1 byte long, how you have it set up should be OK as byte 1 is always zero.  Besides the extended box being checked, everything looks correct to me in your picture.

- Some CAN setups change the byte numbering when you go from little to big endian.  Eg a two byte variable at byte 0 in big endian would start at byte 1 when little endian.

Are you able to receive anything?  Or is the data just erratic?

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