Replaced PDM but dealer still can't get the car to charge

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moonhack

Member
Joined
May 29, 2024
Messages
11
Location
Mexico
Hello everyone and greetings from Mexico.

After having nothing but good experiences with my used 2013 Leaf, I helped a family member buy a 2015 Leaf (6kw, no QC) from an online auction. Sadly, its condition turned out to be misleading and once the battery ran out (after driving it home personally) it got the EV system warning light and was unable to charge, either using 110v or 220v. Everything that could be tried at home was tried, new 12v battery, erasing error codes, and so on, but as it didn't work we towed it to the only Leaf-certified dealership in town.

After a months-long testing process (they only have one Leaf-certified technician and he's also working on every other car in the shop) they concluded it was the PDM as they opened it and found out it was visibly burnt. They also recommended changing three harnesses coming to the PDM but it was going to be very expensive, and as the car was still driveable until the battery ran out I doubt those cables were also bad. The exact part in the car was 292C0-3NF2D, which was awfully expensive new online, but I read here (link) that part no. 292C0-4NP2A was also compatible, and it was accessible enough so we saved up for it and bought it new from an OEM part seller.

The part was new, came sealed on a Nissan-branded box, nothing weird about it. We took it to the dealer and they installed it. But then they called back and said the car still didn't charge, and that there were new error codes coming up. I looked up some things online and apparently Nissan ships new parts that require programming in a blank state, so I told them to try to program it. But they say that they can't do that while error codes appear. They said they were out of ideas (Leafs sold very little here and so the technician has very little practical experience, if any) and that they were going to call Nissan technical support here in Mexico for help.

Now Nissan technical support has replied and, according to the technician, they said that the new PDM part number isn't valid for the car's serial number. I find this very hard to believe as there's lots of evidence online that these PDM replacements are very easy to perform, some people even do it in their garage, some even upgrade their PDM from 3kw to 6kw and it just works.

I would like to send them some official Nissan document where it shows that 292C0-4NP2A is a valid replacement for 292C0-3NF2D, but I can't find it. The link on the original thread with the part list no longer exists. Either way I think this is just an excuse to not work on the car anymore. Can you guys help me find some document where it says this?

On the other hand, what do you guys think is the issue overall? Could it really be the harnesses that weren't replaced, or some other part? I know there are some very knowledgeable people in here, probably more so than in my town's Nissan shop.

Thanks in advance.
 
That is correct. However I assumed it would be fully compatible as I've seen lots of people doing non-direct replacements quite easily...
 
Note that there has been a change in part numbers, where the digit after the dash went from 3 to 4 >>> 292C0-3 went to 292C0-4
 
Not a clue! I did see that some folks have apparently taken the 292C0-3NF3D and used that on the non-QC vehicle--but I would do a thorough web search to verify that. The 292C0-3NF0D 3 kw charger would also probably work, because people have done the reverse swap. Good Luck!
 
So I decided to ask Paweł Drozd, a very skilled Leaf modder, and according to him the new PDM won't work because of different CAN communication. Hold on a second. Could this be solved with a CAN bridge? He says maybe. There's Dala out there who made a 2018 inverter work in an older Leaf with a bridge and some custom code... or maybe the PDM could be reflashed?
 
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I'm a bit baffled that it won't charge. The basic charging messages (0x390, 0x393) and wakeup messages (0x603) are still almost exactly the same between these firmware versions. Usually even with some slightly different messages it will at least still start up.

Yes, it'll be possible to fix this with a CAN bridge but this isn't a publically documented thing. There is currently no comprehensive .dbc file for the charging messages and the differences between generations. So this will require some reverse engineering to get to work.
 
The world-famous Dala just got back to me and also said all 2013-2024 PDMs are plug-and-play, no CAN bridge needed. Well that changes things... I'll try to get those error codes myself and list them here. Maybe it's just a fried harness, or something as easy as clearing old DTCs?
 
UPDATE: The car is still in the dealer's shop, but they sent me a picture of their scanner with the codes that came up. I'm trying to verify if these are all the codes or if there are more, but they are slow to respond.

These are the codes that they sent me:

ABS:
C118C

EV/HEV:
P3194
P31B4
P31B7
U1000
P1574

They all appear as "current" on the scanner. On their screen there seems to be a second page, but they didn't send me that.

What do you guys think?
 
I was told that I should try to clear codes and see which ones stick, so I told that to the tech since I don't have physical access to the car yet... apparently now there are 4 pages of error codes, and because of the CAN communication errors they can't clear them.

This is what comes up now in CONSULT-III:

ABS:
C118C

BCM:
B2193
B2557
B26F2
U1000 (PAST)

SHIFT:
U1000
P18AB

EV/HEV:
P3194
P31B4
P31B7
U1000
P1574
P1610
P1612

BRAKE:
C1A6E
C1A70
U1000
U1510

IPDM E/R:
B2098 (PAST)

I could really use some help from the brightest minds on this forum right now.
 
Those "U1nnn" codes across the several subsystems are CAN Buss communications fault codes and the car will not do much driving or charging without a functional CAN Buss.

A common cause of CAN faults is an old, weak or worn out 12V battery. If the shop haven't kept the battery on a charger then it has likely self-discharged and now the power supply for the CAN is not adequate. Other causes could be rodent damage to wiring or corrosion of contact in connectors.

The first step in every DTC troubleshooting procedure in the FSM---is check the 12V battery. Putting a voltmeter on it is not an adequate check; it can indicate if the voltage is low but doesn't give an indication of capacity.
 
Codes P3194, P31B4, P31B7 and P1574 are also all to do with faulty CAN bus communication. I'd agree that charge the 12V battery (disconnected from the car), or test it and replace it; if that doesn't help, investigate for bad connections or wiring faults in both the "vehicle" CAN bus and the "EV" CAN bus. That's not as difficult as it sounds - most faults can be narrowed down with the 12V battery disconnected and a multimeter on 200 ohm range (there should be a resistance of 60 ohms between CAN-H and CAN-L wires at every connected module; if 120 ohms, one side's open circuit or one of the two modules for the ends of the bus is unplugged; if less than 50 ohms, there's a short circuit; if more than 130 ohms, there's a bad connection or other wiring damage).
 
Thanks for the replies. I went today to the dealer and explained your comments.

They said they would charge the 12v battery, but only a couple hours later they send a picture of a MIdtronics battery tester printout showing that the battery is in good condition with 12.86V, 517CCA and good condition for starting. So according to them it's charged.

Next would be to check wiring faults, right?

I've been thinking about taking the car out of Nissan's shop and sending it to a friend mechanic's shop who is familiar with regular car electronics. Maybe he can figure out the fault faster.
 
Well did they clear the codes after charging the battery, and try using the EVSE again to charge the car? Then read any DTCs?

That's what a mechanic would do if they were trying to troubleshoot an issue, but since that sort of strategy is not in the FSM i would gues that they probably did nothing--waiting for some sign to lead them.

What about some pictures of the so called burnt areas inside the PDM?

Yes indeed all the wiring needed to be inspected and checked for rodent damage, and the connector contacts inspected for corrosion--in order to rule out this as a possibility or find a culprit.

It seems that you will have to be very pro-active in getting this repaired.
 
Well did they clear the codes after charging the battery, and try using the EVSE again to charge the car? Then read any DTCs?
It appears that they're going to do this tomorrow, or so I hope...

What about some pictures of the so called burnt areas inside the PDM?
I attached the only pictures I have. I did not take these, but apparently the three small components pictured were blown away and no longer there.

Yes indeed all the wiring needed to be inspected and checked for rodent damage, and the connector contacts inspected for corrosion--in order to rule out this as a possibility or find a culprit.

It seems that you will have to be very pro-active in getting this repaired.
If there's no other way, then so be it...
 

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I attached the only pictures I have.
It's so sad that the parts that have burned cost at the very most US$5. Though there could be more damage that is not as visible. Now the entire Power Delivery Module was replaced, because of that minor damage. Such wastage.

The problem is to find the people who can figure out what tiny, inexpensive parts to replace, and make the repair.

I'm wondering if 240 V or 120 V AC found its way into the control pilot circuit. If so, the damage may indeed be extensive (and expensive, and perhaps not practical at the component level).

I wonder if it would have been possible to replace just the on-board charger board(s) in the PDM, leaving all the DC-DC and motor controller boards as is. But likely Nissan have decided that the whole thing is one module, and has to be replaced totally if the tiniest part fails.
 
I wonder if it would have been possible to replace just the on-board charger board(s) in the PDM, leaving all the DC-DC and motor controller boards as is. But likely Nissan have decided that the whole thing is one module, and has to be replaced totally if the tiniest part fails.
I think, simply put, that most "mechanic's" and most outside of engineering don't have the knowledge and skill set to diagnose these boards. I include myself.
There are people who do, but the paradox is: they fail infrequently enough that you couldn't make a living setting up a shop to repair them, but for the individuals that can, it turns a very expensive repair to a very cheap one.
Electronics and cars are a mash-up that the skills to repair don't cross over very well. I could do well, but when it comes to board level failures, my only option is to replace the board in question. I could do the soldering if someone could show me the component that has failed (unless obvious burnt/bulging) and suggest a suitable replacement. circuit board diagnoses is a whole different world from even electromechanical stuff.
From Nissans prospective, it would cost more to train their people to be able to work at board level than to let the trouble codes condemn the whole module.
 
but when it comes to board level failures, my only option is to replace the board in question.
That's actually what I meant. My understanding is that the PDM is made up of at least 3 large boards (on-board charger, DC-DC, and motor controller), plus several smaller ones (junction/sensor boards, one that is only present if CHAdeMO option is present, and so on). Plus a lot of metalwork and busbars. It might even be less work to replace just the on-board charger board than to swap out the entire Power Delivery Module. Each board has connectors making it fairly easy even for a mechanic to replace a board, IF (and it's a moderately big IF) the diagnostic process makes it clear which board to replace.

I guess "design for serviceability" isn't enough of a buzzword/catch phrase (yet?) to make this happen.
 
While I find time to visit the Nissan shop again, I decided to dive into the service manuals and look up every single error code that is coming up, to see for myself if it matches up with their description of the problem (that the PDM is incompatible) or if it leans more towards ours (that either the 12V battery is weak, or there's a connection problem).

Well, every single code except for U1510 points at the same thing: check harnesses and connectors of VCM and BCM, and then check VCM and BCM themselves. U1510 seems to be strictly related to the 12V battery. Even the ones in other subsystems all ask to check if there are U1000 errors or EV/HEV errors first, and to address those first. Then I learned that there are indeed, tons of possible error codes for the PDM, including CAN communication errors for the PDM, but as we can see, none of them appear here! Vehicle Charging/PDM subsystem is completely fine according to Nissan's own tools.

I then checked the fail-safe lists on the manuals to see what could cause the car not to charge right now, and very clearly, of ALL the codes, P1610 and P1612 prohibit both starting and charging the car, both of which indicate continuous CAN communication failure between VCM and BCM. Of course, any PDM electrical malfunction would also trigger a fail-safe that prohibits charging the car, but that's not what's happening anymore.

So I think we're getting closer to the fault here. Maybe they didn't connect the harnesses completely, or maybe they mishandled some cable and it broke. Worst case scenario, maybe the VCM got fried?

My question now is, what exactly do I have to test to verify this?
If I'm correct, both the VCM and BCM are behind the glovebox, right?
About the harnesses, where do they plug on the other side?
What tools would I need besides a multimeter?

Thanks
 
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