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CAN bus wired to Diagnostic connector

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OomD:

--- Quote from: kobus on June 23, 2015, 11:16:09 AM ---
--- Quote from: WayneC on March 24, 2015, 09:02:32 AM ---Why BMW did not implement a K-Line to CAN interface in the BMS is a good question, another good question is why they did not retain the K-Line for engine/ABS electronics as they did in the cars

--- End quote ---
AFAIK, there are laws (for environmental reasons) governing the OBD spec on cars (and thus the reason for retaining the K-line on cars because it is part of the spec), but these laws do not apply to motorcycles.

--- End quote ---
Yes there are laws, but those laws do not specify that the K-line interface has to be used. In fact, many modern cars have started using the CAN bus on the OBDII diagnostics connector years ago, as was actually required by the Europeans.

kobus:
It does. The law says you have to implement the OBD spec - and K-line is part of the spec.

The point is that cars have to comply with ODB and bikes do not.

WayneC:
I noticed in some Euro countries that while OBD was not mandated for the bikes, the bikes became caught up by annual emissions checks that are part of rego inspections. Always meant to look into it further but there are so many other things to do other than reading dry regulatory docs  ;D

OomD:

--- Quote from: kobus on June 23, 2015, 12:29:06 PM ---It does. The law says you have to implement the OBD spec - and K-line is part of the spec.

The point is that cars have to comply with ODB and bikes do not.

--- End quote ---
Yes, the law says they have to implement the OBDII protocol. But, there are 5 different physical layers they can choose from:

1. KWP2000 protocol over K-Line, used by most manufacturers, possibly in conjunction with the L line for device addressing.
2. VPW protocol - used by older Ford and General motors and variants thereof.
3. CAN high speed
4. CAN low speed
5. Variants of the CAN but with 29-bit ID instead of 11-bit ID

All of these have to implement the J1979 comms protocol on top of their physical layer. And the J1979 is the mandatory part. However, manufacturers are free to use any of the physical layers... until 2008 that was when Europe deemed CAN a minimum necessity.

So, CAN is a requirement for european vehicles.

kobus:
... but "vehicles" do not include motorcycles. Maybe it's because there are 2 wheels less :)

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