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JeremyW
Posts: 1545
Joined: Sun Nov 13, 2011 12:53 am
Delivery Date: 23 Jun 2012
Leaf Number: 19136
Location: San Gabriel, CA

Re: LEAF CANbus decoding. (Open discussion)

Tue Nov 19, 2013 5:10 pm

So I got a PCAN tool to help do some decoding of the CAN buses, with emphasis on helping decode climate control and remote queries. Playing around with it today, I used TickTock's doc to help find climate related values on the car CAN bus. Here's some observations:

510 byte 4- tracks "climate control" under the energy info screen exactly (goes up and down in lock step)
50a byte 18- 1A/1B observed with AC on (too cold for full AC power), up with compressor engagement (when I hear the compressor kick on) and slowly drops down to 18 when turning off climate control. I think it is "refrigerant pressure signal detection value sent from VCM" as listed in the service manual

5a9 byte looks to be eco mode flags for climate/other reasons. I observed a change when switching back and forth between eco and drive (but remained stationary) but NOT between drive and park.
Climate on (heat):
eco 16 30 de c3 50 00 00
drv 78 14 50 0d 83 00 00
Climate off:
eco 87 18 b0 de c3 50 00
drv 86 16 80 0d 43 00 00
The first byte varied by 1 bit in a few readings though.

Remote climate/SOC:
I observed a new message header/address of 68 on the EV CAN bus that appears exactly 1 time when invoking a remote climate request. I tried sending this through PCAN View but it didn't do anything. Bummer. I suspect it is the TCU (it is on the EV bus according to the service manual) but there might be more to it...

I'm looking at trying out CAN Trace for a free 30 day trial, but it's 495€ for the full version. :shock: It does have some very nifty "database" options which can convert hex to "real world" values, and there is logging and other features... wish they made a "lite" version!
Former 2012 SL leasee 6/23/12 - 9/23/15
Former Fit EV leasee.
Now driving Spark EV and Model 3.

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TickTock
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Delivery Date: 31 May 2011
Leaf Number: 3626
Location: Queen Creek, Arizona
Contact: Website

Re: LEAF CANbus decoding. (Open discussion)

Tue Nov 19, 2013 5:34 pm

Nice find! 510:4 is something I was looking for (I want to take climate control power into consideration for my DTE just like the Leaf does).

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TickTock
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Delivery Date: 31 May 2011
Leaf Number: 3626
Location: Queen Creek, Arizona
Contact: Website

Re: LEAF CANbus decoding. (Open discussion)

Wed Nov 20, 2013 6:31 am

On the 50a message above, I assume you mean byte 4. Also what is the payload for of msgId:068 for CC request?

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TickTock
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Re: LEAF CANbus decoding. (Open discussion)

Wed Nov 20, 2013 7:52 am

I added msgId:510 byte:4 (5103) to my watchpoints on CANary and observed a few more details. The MSB appears to be CC on/off. When I turn off the heater, bit7 is immediately cleared but the rest of the bits drop more slowly to zero. I was watching the power into the battery (did all this while parked BTW) and confirmed that the actual power draw also tapered off with those bits so they do appear to be an indicator of climate control power. I also noted that 0C corresponded to 1.5kW and 18 to 3kW (dropped the msb). I never saw odd numbers so it appears only bits 6:1 are valid. So, shifting right, that makes 6=1.5kW and C=3kW or 0.25kW per tic.

I plan to subtract this power from the power being drawn from the battery for the purpose of computing (and recording) driving efficiency and adding it back in when displaying so the variability due to CC use will be eliminated and the driver can see the impact of turning CC on/off immediately. No big revelation, the Leaf already does this - CANary will just do it better. :-) Nice find, Jeremy!

like2bike
Posts: 68
Joined: Sat Mar 23, 2013 9:35 pm
Delivery Date: 19 Mar 2013
Leaf Number: 00581
Location: Long Island, NY

Re: LEAF CANbus decoding. (Open discussion)

Thu Nov 21, 2013 7:36 pm

TickTock,
I'm fairly sure that the GIDs field in your canmsgs document is incorrect. On my MY13, I find it is at CarCAN msgID 5B3, Byte4:bit0 to Byte5:bits7-0 (Byte0 to Byte7 ordering). Your list is a great help, thanks for the effort!
2019 Chevy Bolt LT with DCFC and DC I, II
2016 Leaf S with QC
2013 Leaf S with QC, sold to a friend 8/19
Long Island, NY

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TickTock
Posts: 1701
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Delivery Date: 31 May 2011
Leaf Number: 3626
Location: Queen Creek, Arizona
Contact: Website

Re: LEAF CANbus decoding. (Open discussion)

Thu Nov 21, 2013 9:26 pm

like2bike wrote:TickTock,
I'm fairly sure that the GIDs field in your canmsgs document is incorrect. On my MY13, I find it is at CarCAN msgID 5B3, Byte4:bit0 to Byte5:bits7-0 (Byte0 to Byte7 ordering). Your list is a great help, thanks for the effort!
Quite right. Thanks! I have corrected it.

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TickTock
Posts: 1701
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Delivery Date: 31 May 2011
Leaf Number: 3626
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Contact: Website

Re: LEAF CANbus decoding. (Open discussion)

Mon Nov 25, 2013 2:47 pm

Greg has been off the grid for a few weeks but is now back. He is more than happy share his learnings:
GregH wrote:Send:
792: 03 22 12 10 for ampacity
Returns
793: ?? ?? 12 10 xx xx
My code shifts this number xxxx>>4 to get an approximate amps

792: 03 22 12 30 for line voltage
Returns
793: ?? ?? 12 30 xx xx
My code shifts this number xxxx>>7 to get an approximate volts.
garygid wrote:Good work, my friend.
Do you have the MsgIDs that GregH uses to determine the
J1772 Pilot signal percentage or Max-Amps value?

It would be nice to see what current capacity each EVSE has
to offer.

Cheers, Gary

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garygid
Gold Member
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Joined: Wed Apr 21, 2010 8:10 am
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Leaf Number: 000855
Location: Laguna Hills, Orange Co, CA

Re: LEAF CANbus decoding. (Open discussion)

Tue Nov 26, 2013 8:25 am

I am so very pleased that you (several) guys are
discovering these great data-gems in the LEAF.

The first seeds of CAN investigations sown by turbo2ltr
approximately 3 years ago are really bearing fruit.
Well done, all.

Sincerely, Gary
See SOC/GID-Meter and CAN-Do Info
2010 Prius
2011 LEAF, 2014 Tesla S85
2018 & 2019 Tesla Model 3
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Solar PV: 33 x 225W -> 7 kW max AC
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JeremyW
Posts: 1545
Joined: Sun Nov 13, 2011 12:53 am
Delivery Date: 23 Jun 2012
Leaf Number: 19136
Location: San Gabriel, CA

Re: LEAF CANbus decoding. (Open discussion)

Wed Dec 11, 2013 9:51 pm

Sadly, there is no "magic" can bus command to wake up the VCM or the rest of the leaf. The Telematics module wakes up the VCM over a dedicated logic line, according to the service manual. The command I was seeing 68C (I thought it was 68 but I wasn't looking closely enough!) seems to be the first message on the bus when starting the leaf regardless of mode (you pressing the start button or doing a remote request). The payload for 68C is 00 and appears only one time at the start.

:(
Former 2012 SL leasee 6/23/12 - 9/23/15
Former Fit EV leasee.
Now driving Spark EV and Model 3.

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JeremyW
Posts: 1545
Joined: Sun Nov 13, 2011 12:53 am
Delivery Date: 23 Jun 2012
Leaf Number: 19136
Location: San Gabriel, CA

Re: LEAF CANbus decoding. (Open discussion)

Wed Dec 11, 2013 9:59 pm

On a lighter note, on the car can bus:
54B byte 4 is user requested fan speed
50A byte 4 is 80/A0 for off/on (respectively) of the rear defrost.
Former 2012 SL leasee 6/23/12 - 9/23/15
Former Fit EV leasee.
Now driving Spark EV and Model 3.

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