Cell Voltage Loss Inspection test (cell-pair test), P33E6

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GroundHog

Member
Joined
Feb 2, 2014
Messages
24
In the 2013 repair manual, pages EVB160-EVB164 describe the work to do in the event of error code P33E6 (Cell Controller). Steps 3-5 include the CVLI test which instructs that the minimum cell voltage must be 3,712mV or less for the test to be valid and that the proper condition of the test is that the battery must be discharged down to 2 segments or less. The CVLI test has already been discussed in previous threads.

My question is what causes error code P33E6? If you read the repair manual strickly, an out of balance cell module may only need to be replaced if error code P33E6 is registered.

Has anyone had the P33E6 error code?

Does this error code need to be specifically requested? OR is it automatically stored somewhere so that when they "scan for error codes" it can be found.

In the manual it says:
Perform DTC confirmation procedure.
With Consult
1. Turn power switch ON and wait for 10 seconds or more.
2. Select "Self Diagnostic Result" of "HV BAT".
3. Check DTC.
Is P33E6 detected?
YES >> continue to EVB-160 diagnosis procedure which includes the CVLI test.

Is this what the dealer is doing when they 'scan for error codes', or is this a more in-depth error-code check?

Also, the DTC detecting condition for P33E6 is "With the power switch ON and no load condition, the difference between the maximum voltage and minimum voltage exceeds the allowable range."
What is that allowable range? This seems to imply something other than the cell judgement value which is used in the CVLI test. The only specs I can find in the manual is that at a total voltage of 317V, the cell modules should be "approx. 3,200-3,400 mV", and at a total voltage of 393 V, the cell modules should be "approx. 4,000-4,200 mV". These specs are odd because they imply the same voltage range at full charge and at empty, which is clearly not what most people observe. At 317 V (usually 7 GIDs), my module's voltage range is
3092-3376 mV
3055-3350 mV
3012-3353 mV
3013-3334 mV
3058-3327 mV
3008-3326 mV
Depending on what "approximately" means, these should have all triggered the error code, but my dealer says they get nothing when they scan for error codes.

One other question, Has anyone ever had a cell module replaced? I've heard of the people who were contacted by Nissan for this to be done, but does anyone have more of a first-hand knowledge of this being done? I'd like to know the conditions.


Thanks in advance! Maybe we can all help to improve on Nissan's diagnostics.
 
Wow, so just to be sure. If anyone has had their car register this error code, P33E6. PLEASE post your experience and the outcome.
Thanks
 
I've got the P33E6 code on my env200 (MY15, 61000 km), as seen on Leaf Spy Pro. Booked service on Monday, we'll see how it goes.
 
What was the outcome?
I've seen this code on a battery too, also i can see one particular cell gets very low under load.... as low as 2.2-2.4v (30kwh bms updated). Some other weak cells are identified too.
 
Dala said:
I have replaced cells on my own. Here is a writeup if you are interested: http://www.japtoys.net/forum/viewtopic.php?f=10&t=3613

Really nice work! Very impressive. Thank you.
I have the exact same problem in a 2012 Nissan Leaf with 2000km I just bought with a low cell voltage around the middle, turtle+motor power limited and all, but thankfully mine is under warranty and I am way less brave that you are.
 
Dala said:
I have replaced cells on my own. Here is a writeup if you are interested: http://www.japtoys.net/forum/viewtopic.php?f=10&t=3613
Dala;
Quite happy with my 2012 leaf, especially with the "Lizard" replacement battery. However, it does seem that there are two weak cell assemblies - # 75,76. Do you have a recommended procedure that might help rebalance - without "peeling" to the individual cells?

Any success with a replacement business? A company called Fenix Power is working on it in the US - no updates for sometime however :roll:


Leaf bad cells.jpg

My wheels - made a real difference in appearances from the stock SL's (at least IMO)
Leaf wheels.jpg
 
Marktm said:
If I recall, this was when "turtle" was activated. I may have even used the heater until the drive system shutdown. The error code P33E6 was not set.
Your story is probably similar JerrtyAZ then: meets cvli criteria but absent the DTC Nissan is not interested.

In your shoes I would complain of a loss of power and let them figure out why.
 
I have thought of taking it to the same dealer that did the replacement and at least get the facts on record. The problem is that LeafSpy has the "facts" and without a DTC, I don't think they will do anything. I've been working with this dealer on some vehicle to grid initiatives and fleet purchases, so they might take it to their EV "experts"? Probably worth a try.

BTW, the "normal" mv range is 20-30 mv when above VLBW, and the range seems about as expected, so I do wonder if the two cells might need better balancing than the management system can normally provide. Above my pay grade, however.
 
The only fact I would relay is that the car goes into turtle mode when it still has charge in the battery.
 
Guys, I live in Houston, TX - the only steep hills are freeway overpasses where everyone is going between 75 and 95 mph! OK, I might be exaggerating :mrgreen:

It's very interesting-what you are recommending! So you expect that this might actually help throw the code and/or simply be obvious from the "feel" and/or the power level recorded on LeafSpy or even the GOM - that the power level is restricted by the "bad" cells? I think I see where you are going.
 
Honestly, while the cells are lower, I don't know that I'd call them bad. 5.5% SOC is very very low, so they're probably just the weakest two.

Its very different than when you're at 25 or 50% SOC and you see that difference. If that happens, you have bad cells. Given the li-ion discharge curve, those cells are within 5% capacity difference of the others. Replacing the cells would likely provide you very little difference on range.

I used to get 250-300mv differences in my car all the time at VLBW, but that's because it had 7 bars.
 
Lothsahn said:
5.5% SOC is very very low, so they're probably just the weakest two.
Note that the 5.5% SoC in this pack is a voltage of 334 volts. That is way above turtle.

The manual will have to be checked, but I *think* that the LEAF should have full power from VLBW and above.

As for how to document power loss: it may be as simple as less power rings light up on the display under full acceleration; or it may take a simple comparison of say ... 0-60 mph time.
 
Marktm said:
So you expect that this might actually help throw the code and/or simply be obvious from the "feel" and/or the power level recorded on LeafSpy or even the GOM - that the power level is restricted by the "bad" cells? I think I see where you are going.
Right, and you do not need a hill.

Just document that maximum power is hobbled when it should not be. Hills are recommended because they give you an opportunity to floor the go pedal for a longer time. I imagine that flooring both pedals at the same time is the same test.
 
Will set up a "test", take data and get back. Fun project for a retired guy! Just hope I don't have to push my leaf for a block to get to the front of my house after I went too far with battery depletion :shock: I was definitely a newbie at that time!

Interesting concept of pushing both "pedals" - it would seem regen and accel at the same time would cancel, or is the CAN system smart enough to only use the disks brakes when accelerating?
 
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