Posts: 2240
Joined: Tue Dec 17, 2013 10:53 pm
Delivery Date: 22 Nov 2013
Leaf Number: 416635
Location: SoCal

Re: LEAF CANbus decoding. (Open discussion)

Sun Jun 16, 2019 11:48 am

JeremyW wrote: It's likely the CAR CAN bus has been removed from the OBD connector, and replaced with a new "diagnostic bus" that talks just to the VCM, which can relay the message onto the requested module by decoding the query address and sending it onward to the appropriate bus where the module is located.
That's basically what's done on most all vehicles since 2005, i.e. using a single CAN bus with a central gateway (CG) that communicates
with the multiple buses (high speed engine/ABS & low speed single-ended comfort control) to access the various vehicle ECUs. Typically the
CG also controls which ECUs are active in the network, e.g. what comfort features the vehicle has installed.
#1 Leaf SL MY 9/13: 74K miles, 48 Ahrs, 5.2 miles/kWh (average), Hx=70, SOH=78, L2 - 100% > 1000, temp < 95F, (DOD) > 20 Ahrs
#2 Leaf SL MY 12/18: 4.5K miles, 115 Ahrs, 5.5 miles/kWh (average), Hx=98, SOH=99, DOD > 20%, temp < 105F

Posts: 42
Joined: Thu Jul 09, 2015 1:58 am
Delivery Date: 12 Dec 2015
Leaf Number: 004321
Location: New Zealand

Re: LEAF CANbus decoding. (Open discussion)

Sat Jul 13, 2019 12:26 am

JeremyW wrote: Typically the CG also controls which ECUs are active in the network, e.g. what comfort features the vehicle has installed.
Is this likely to be what decides if options such as Cruise Control are enabled? I tried to upgrade my Leaf to this by simply installing the steering wheel button assembly. There was a connector right there in the wheel for the loom to plug in to. Sadly it wasn't as simple as that. I didn't really think it would be but you never know! :D

Posts: 16
Joined: Sat Apr 06, 2019 5:52 pm
Delivery Date: 07 Apr 2019

Re: LEAF CANbus decoding. (Open discussion)

Sun Aug 25, 2019 12:27 pm

I'm trying to put a Nissan Leaf drivetrain into a classic Mini. Getting the complete Leaf components working on a bench has been somewhat frustrating, and is ultimately not the ideal solution—it's a cost-saving measure vs buying aftermarket components.

I'm at the point where I'm ready to shell out more for BMS, charging, and DC-DC conversion, but it seems like a shame to spend another $3k on components that are (arguably) inferior just because I can't communicate with the components I already have.

I'm a software engineer by trade, so I was thinking about building a CAN controller for these components, but I've never messed with an Arduino, the CAN protocol, or anything specific to an automobile's proprietary communications protocol before. It seems like something that would already have been done by someone more knowledgeable, but maybe this hobby is still a niche of niches.

Before I go back through 8 years of this thread, is there a summation somewhere? I've read that the Nissan Leaf CAN bus messages have all been decoded, but I can't find any central location for information that might help me actually control these components...

Edit: If anyone stumbles on this thread from the Greater Internet, a summation is that the first 40 pages talk about decoding and general CAN interface stuff, and after that gets into controlling the charger and motor a bit. Lots of info, but no I-can-use-this-component breakthroughs yet...This forum seems like a good place to search for more information:


Thread on "active" CAN bus stuff (getting info from the BMS/LBC):


There is also a pretty good forum for general EV conversions here: https://www.diyelectriccar.com/forums/

Here's a spreadsheet of all the decoded Leaf CAN messages: https://docs.google.com/spreadsheets/d/ ... Fm0P7ouwg/

Here's a thread that ends with some success in controlling the inverter: viewtopic.php?f=44&t=25027

More inverter details from that thread: http://productions.8dromeda.net/c55-lea ... tocol.html

Jimma Hanna's video on getting the DC-DC converter working: https://www.youtube.com/watch?v=BMhcHkOg-Mk

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