LEAF CANbus decoding. (Open discussion)

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garygTx said:
Has anyone captured a log from setting the charge timer? I suspect that will create a CAN message, so we might be able to set a charge level other than 80 or 100%. That would be ideal for me, as an 80% charge may not be enough for lunch runs/errands, but 100% is really over kill.
This is something we've been looking for for some time but have not been able to identify any messages to start or stop charging. I personally wanted a 50% or "storage" option so I could come home, bring it to the storage level immediately and then let the END timer charge the rest in the morning. I've been toying with adding a simple IR link to a relay on the EVSE to cut power when the target charge level is reached but now that they rolled out the warranty I am less concerned so this became a lower priority.
 
TickTock said:
I wonder if this is a carry-over from ICE vehicles (maybe they were trying to compensate for engine compartment heat skewing the sensor and the same algorithm was copied to the LEAF even though there is no significant heat buildup to speak of).
Very plausible theory. I imagine that stopping at a red light in an ICE when there isn't any wind (especially at a large and busy intersection mid-day with the sun out) would see a large spike in temperatures.
 
It appears the 1CA brake pressure message does not exist on MY2013 LEAFs. I was playing back one of the logs I got from LEAFfan's new car (characterizing his battery ESR) and I noticed I never heard my brake pressure monitor chirp. At first I thought, "Damn! He *is* good!" but on closer inspection I discovered that the 1CA messages were absent from the log. Hopefully there is another equivalent message.
 
TickTock said:
It appears the 1CA brake pressure message does not exist on MY2013 LEAFs. I was playing back one of the logs I got from LEAFfan's new car (characterizing his battery ESR) and I noticed I never heard my brake pressure monitor chirp. At first I thought, "Damn! He *is* good!" but on closer inspection I discovered that the 1CA messages were absent from the log. Hopefully there is another equivalent message.
Appears MY2013 Leafs do share the brake pressure in CARcan msdId:292:D7. Update rate is less frequent but probably fast enough for the monitor. This message is also present on my 2011 so I can use the same formula for all models.
 
TickTock said:
TickTock said:
It appears the 1CA brake pressure message does not exist on MY2013 LEAFs. I was playing back one of the logs I got from LEAFfan's new car (characterizing his battery ESR) and I noticed I never heard my brake pressure monitor chirp. At first I thought, "Damn! He *is* good!" but on closer inspection I discovered that the 1CA messages were absent from the log. Hopefully there is another equivalent message.
Appears MY2013 Leafs do share the brake pressure in CARcan msdId:292:D7. Update rate is less frequent but probably fast enough for the monitor. This message is also present on my 2011 so I can use the same formula for all models.

With B mode I rarely use any friction brakes. I usually use the brake to keep from 'creeping'.
 
Did anybody find a value for the voltage of the 12v buss that
could be observed by passive-listening to the CAN Messages on
either the EV or the CAR CAN bus?

I think that I remember that the value was found in two bytes
of some Request-Response messages, but possibly not in the
passive messages?

Thanks.
 
I spent a little time trying to find a passive message containing it but so far unsuccessful. Now that we know what the sensor is outputting from the active request, it should be easier to find if it exists. On my to-do list...
 
Not sure if you'd be interested, but I've got a similar project going on for my 370Z. Here's a link to my spreadsheet on the 370Z CAN, which seems to share a bunch with the Leaf's normal car CAN. I'm not sure how far I want to take this yet, but I'm posting my progress on my blog as well (http://www.straybytes.com)

https://docs.google.com/spreadsheet/ccc?key=0AnNSKKWgqclKdGhzNDNzUnV4bWctSHhrdjJacUhhR3c&usp=sharing

PS: I find it very odd that we both decided on VB6 to make an interface program. I just happened to have an old copy lying around from college and fired it up.

-Brad
 
Thanks for sharing, Brad, this is a nice contribution. You are right - there are a lot of common messages and I already see a lot of information in your document that we had not yet established for the LEAF. On the Leaf, 292:G appears to be brake pressure or applied friction rather than brake pedal position. It goes away as regen is applied for the same brake pedal position. On the Z, it may effectively be brake pedal position but I wonder if it is really applied friction as it is on the LEAF. Also I do not think 292:D is battery voltage. It mostly hovers around 7f-80 for me too but I know the battery voltage fluctuates from 11-14. Curious, though, I see it dip twice during a short log I took while going through a car wash. I have spent many hours trying to find a passive message containing accessory battery voltage and have come up empty even knowing what the sensor is outputting via the active message. Have you tried querying the 370Z with the 79b/7bb message pairs like we do on the LEAF?

I'll keep looking to see what other gems we can gather. You probably already found it, but here is my spreadsheet with the LEAF messages.
 
TickTock said:
TickTock said:
It appears the temperature messages (EVcan 546:D7 and CARcan 510:D8) do not suffer from the same long delay/time_constant as the dash eyebrow display. I added the ambient to the debug screen on CANary and although I am within 1 degree when the car is at equilibrium, the message is much more responsive to outside changes. I ran an errand this afternoon. When I left the garage (80F), CANary and LEAF dash matched. Within minutes of driving in 110F weather, the CANary (msgID 546/510) temp quickly rose to 109F but the dash only increased to 84. I double-checked the owners manual and it is, indeed, supposed to be outside air temperature (I thought maybe it was showing cabin temperature). I wonder why the dash temp has so much filtering - makes it rather less useful. I think I will add outside ambient to one of the operational screens.
OK. Even more strange - the filter appears to be asymmetrical. This morning my garage was warmer than outside. As expected, the canbus message matched the dash outside temp display when I got in but unlike before when it was warmer outside, it continued to track the dash display perfectly as it dropped from 90F to 86F. So, it appears the dash display delays or filters rising temperatures but not falling. This would be consistent with my prior experience at car washes (temperature quickly drops after passing through the car wash but takes 20 minutes or so to return to something resembling the outside temp).

The Leaf is the nicest car I've ever owned so I've never had an outside temperature gauge before. Do ICE ambient gauges do the same? I wonder if this is a carry-over from ICE vehicles (maybe they were trying to compensate for engine compartment heat skewing the sensor and the same algorithm was copied to the LEAF even though there is no significant heat buildup to speak of).
drees said:
Very plausible theory. I imagine that stopping at a red light in an ICE when there isn't any wind (especially at a large and busy intersection mid-day with the sun out) would see a large spike in temperatures.
Since adding ambient to CANary, I have confirmed that this asymmetric filtering wasn't my imagination. It tracks very close after a long soak (overnight in the garage or at the end of the day at work) and as temperature falls, but not as temperature rises. I drove through a carwash yesterday. Both started at 96F and dropped together to 85F as I passed through. After leaving the carwash, the CANary ambient display climbed at a rate of about 1 degree per minute and got all the way to 97F before the dash ambient display changed from 85 to 86F. By the time I got home CANary was settled at 98F but the dash was only at 92 (but still climbing presumably).
 
TickTock said:
On the Leaf, 292:G appears to be brake pressure or applied friction rather than brake pedal position.
You may be right. I'll experiment a little more with this one to differentiate between the two.

TickTock said:
Also I do not think 292:D is battery voltage. It mostly hovers around 7f-80 for me too but I know the battery voltage fluctuates from 11-14.
I didn't think the numbers seemed right, but it has to be something similar. It seems to dip when I roll the windows up and down, which may be from the inrush current for the motors.

TickTock said:
Have you tried querying the 370Z with the 79b/7bb message pairs like we do on the LEAF?
I have OBD querying working for the 7DF/7E8 message pairs. What is 79B/7BB? Is it specific to a module in the LEAF?
 
brad370 said:
TickTock said:
On the Leaf, 292:G appears to be brake pressure or applied friction rather than brake pedal position.
You may be right. I'll experiment a little more with this one to differentiate between the two.

TickTock said:
Also I do not think 292:D is battery voltage. It mostly hovers around 7f-80 for me too but I know the battery voltage fluctuates from 11-14.
I didn't think the numbers seemed right, but it has to be something similar. It seems to dip when I roll the windows up and down, which may be from the inrush current for the motors.

TickTock said:
Have you tried querying the 370Z with the 79b/7bb message pairs like we do on the LEAF?
I have OBD querying working for the 7DF/7E8 message pairs. What is 79B/7BB? Is it specific to a module in the LEAF?
79B/7BB is the HV Battery. There is no 7DF/7E8 on the Leaf.
 
The 7DF command is a general broadcast OBD2 command. Responses are in the range of 7E8-7EF depending on which module responds. This is standard since 2008. OBD2 PIDs

Edit: I should clarify that it's standard, but maybe not on hybrid/electric vehicles. I'll stay out of your LEAF business and just try to contribute any info I find on the 370Z.
 
Looks like my prior post got missed. I am reasonably certain that CarCan 5B3:D2>>1 contains the SOH value that is read by the Nissan DV-R test equipment and have it on good authority that this is the first thing they look at for any 4 bar losers brought in for warranty work. I have gathered a few datapoints (three cars - mine and two 2013 models) and from those those it appears to be very strongly correlated to AH/65.xx. My car, immediately after getting reset plus the two 2013's indicate Ah/65.6. However, once my car established it's true capacity near 70%, I occasionally get 1% error between the read SOH and the computed Ah/65.6 value. I was hoping we could get this measurement into some more devices so we can get more datapoints and work on a formula to compute this SOH for those devices without access to passive CarCan data.
 
I would like to add this to Leaf Spy. By D2 you mean the second data byte (numbering 1-8).

Use only the high 7 bits or are we dividing by two so the number is xxx.0% or xxx.5% where xxx=0 to 100.

I would just read this number once when Leaf Spy is started as it needs special listen code.
 
Yes, I am using Gary's nomenclature so D2=the second data byte. Appears to be just the upper 7 bits (bit 0 does not give a 0.5% resolution). Lucky for you, this is the same CarCan message containing gids so I suspect you are already reading it :).
 
Gary, you asked if this tracked cap bar loss. The answer is "it should." However, cap bars appear to have ~2month time-constant associated with them whereas this reading is more immediate.

This is what I read from my car when I dropped it off for the sw update on 7/10:
  • Ah = 45.59
    SOH = 68%
    Xfactor = 62.4%
    Cap bars = 9

When I picked it up I read:
  • Ah = 65.6 (seeing this along with the 100 reset value led me to the conclusion that 65.6 is considered 100%)
    SOH = 100%
    Xfactor = 100%
    Cap bars = 12

About 3 miles down the road it changed to:
  • Ah = 65.6
    SOH = 100%
    Xfactor = 50.9%
    Cap bars = 12

The next day after a 100% charge, I read:
  • Ah = 46.92
    SOH = 72%
    Xfactor = 50.9%
    Cap bars = 12

My cap bars are presently at 11 (re-lost the top bar on 9/4). SOH appears to get updated after each charge, but it takes months for the cap bars to reflect this. Since degradation is actually much slower than the step function caused by the reset, I suspect that cap bars should track SOH much more closely than my present condition.
 
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