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

[nlspace]

A DVM with an assortment of clips, pins, and jumper wires can be your best friend in chasing this down.


Ring out the continuity of each suspect wire with due caution to disconnect the 12V supply as needed. e.g don't be probing around and accidentally short out adjacent pins that might be energized.

Get a good set of plastic clip and panel removal tools to get access and inspect wiring and connectors.

Whatever pulse caused the initial damage to the board may have had sufficient energy to internally damage some wire--may not be externally visible but continuity check might find it.

i made this diagram for the early model cars but haven't found the equivalent to make for late models,

 

[nlspace]

The control lines for the PDM come in thru a round circular connector at the back corner (toward the firewall on the right hand side of the car).

The PDM lid can be removed for probing but there is a lid-interlock that would prevent operations with power applied.

There is some connector info on this thread,
https://mynissanleaf.com/threads/po...technical-notes-and-details.35626/post-644387

but i noticed that many of the picture links have expired..? That's a bummer.

The damage to this board looks similar to yours,
https://mynissanleaf.com/threads/6-6-kw-charger-on-2013-s-model.21106/post-642565

 

[moonhack]

Judging from the fail-safe conditions of the error codes, I have a hunch that neither the modules nor the wires are actually damaged... if they were, the car would have been immobilized from the start, but it was actually driveable until the battery ran out. PDM error codes don't immobilize the vehicle, they just prohibit charging. If VCM/BCM communication errors are appearing now, it must be something as simple as a badly plugged connector. Maybe some connector is completely disconnected.

In fact, I would bet the problem is the connector from the engine bay side, as the dashboard was never removed, and nothing was disassembled from inside the cabin. Therefore I would like to check the connections from under the hood. However, I'm having problems finding a wiring diagram for the black harness where the VCM, BCM and other modules plug into.

Could someone post some pictures of how and where these modules plug into the harness where they communicate with each other, particularly from the engine bay side?

Thanks

 

[moonhack]

Well, the saga is over with a happy ending.

Since the dealership techs didn't want to even look at the car anymore, I decided to tow it home, completely dead and filthy inside and out, with the bottom covers removed and placed on the back seat, no gas on the AC compressor, and the wheels all out of alignment.

First thing I found out was that the 12V battery was drained, and only had around 6V. I took it to Autozone for charging and the next day installed it, following the instructions in this post to a T. The car turns on, i-key error comes up. I use LeafSpy to delete most of the error codes, but the P1610 lock is still there. I follow the instructions again to reboot the car, wait 15 minutes before plugging the battery back on, and then follow the instructions on the service manual for removing P1610, which also removes the i-key error. It works, and I clear all remaining errors through LeafSpy. I then plug the car into my 240V home charger and it starts charging right away. 4 hours later the battery is at 100% with 9mV difference between cells.

The car is now chargeable and driveable for the first time in months. The Nissan dealership techs were lying to my face all this time about the PDM being an incompatible part, about the 12V battery being fine and it still not working, and did not even bother trying resetting the car computers to see if the errors were real or not. I paid them extra to physically inspect the harnesses and all they did was to run a check on Consult 3. And they didn't even finish the service in the end. Dala was right all along about it being a plug-and-play part regardless of the model year, and this forum was right about a low 12V battery causing all sorts of errors. It wasn't even a faulty harness as I thought it could be.

Needless to say, I don't think I'll buy another Nissan EV in the future.

 

[nlspace]

Dala was right all along about it being a plug-and-play part regardless of the model year, and this forum was right about a low 12V battery causing all sorts of errors.

Thanks for closing the story about your issue, many times we never hear back on the resolution or status.

That comes back to the first step in the FSM for troubleshooting almost every DTC: Check the 12V battery.

Old, weak or worn out and low 12V battery voltage has been reported on this and other EV forums in hundreds of posts.

 

[Stanton]

Needless to say, I don't think I'll buy another Nissan EV in the future.

I don't think it's the car so much as the service/technician incompetence. Just sayin'
Good EV techs are still hard to find.

 

[cornbinder89]

I don't think it's the car so much as the service/technician incompetence. Just sayin'
Good EV techs are still hard to find.

I think this is sooo true!
A Nissan dealership mechanic has to be up on all there line of ICE cars and one EV! which do you think they will spend most of their time and effort on? Not saying it is right, just how things are.
There are specialty shops that deal in only EV's or Hybrids that are likely worlds beyond the dealership's ability. We need more of these shops.

 

[moonhack]

Yes, the Leaf is a good car, and I plan on keeping mine as long as possible, but with this kind of official service when something goes wrong, extremely slow, full of lies and unwillingness, if I wasn't tech-oriented with a DIY mentality, I would have ended up selling the car to a junkyard and losing a lot of money. In this dealership, which is the only "Leaf-certified" one where I live, everyone is an old ICE car technician type, even the one employee who is supposed to be the Leaf technician. They didn't bother reading service manuals, looking up DTCs, giving it a good think, they seemed to have no initiative to learn a new technology, they seemed burnt out from having the car there and nothing was moving forwards anymore. Anybody else would give up on electric cars or at least on the brand after experiencing that, especially with so much competition with better reputation on service.

 

[moonhack]

I think this is sooo true!
A Nissan dealership mechanic has to be up on all there line of ICE cars and one EV! which do you think they will spend most of their time and effort on? Not saying it is right, just how things are.
There are specialty shops that deal in only EV's or Hybrids that are likely worlds beyond the dealership's ability. We need more of these shops.

Indeed, that was the situation. There were like 30 cars on the shop and only one was electric. And the one tech who "knew" how to fix the Leaf was also working on all other 30 cars at the same time.

 

[MozzoAU]

FWIW the poor skillets you experienced aren't limited to Nissan dealers. My second EV is another make and the dealership experience has been worse than my Nissan dealer to date.

 

[coulomb]

the 12V battery was drained, and only had around 6V. I took it to Autozone for charging and the next day installed it,

That auxiliary battery is running on borrowed time. It won't last, even if it's only a year old. Lead acid batteries don't like being fully discharged.

It may work acceptably with a reduced life, but I'd expect it to be problematic, especially in winter. There is maybe a 10% chance that it will continue to work for years, having only lost a few percent of life.

 

[GentleGiant]

Agreed, change the 12v battery for one that hasnt been drained to nothing; especially if it is a "Calcium Technology" formulation, as opposed to the older (cheaper) Lead-Acid.

I have had nothing but issues with those Calcium tech batteries since they came out 20 years ago; and at one point was getting a free replacement from Halfrauds every 18 months; as they would suddenly stop holding a charge beyond 24 hours.

 

[moonhack]

That auxiliary battery is running on borrowed time. It won't last, even if it's only a year old. Lead acid batteries don't like being fully discharged.

It may work acceptably with a reduced life, but I'd expect it to be problematic, especially in winter. There is maybe a 10% chance that it will continue to work for years, having only lost a few percent of life.

Good to know. At least it has a warranty so it's not on me if it fails.

 

[LeafNissan1]

The Nissan dealership techs were lying to my face all this time about the PDM being an incompatible part, about the 12V battery being fine and it still not working, and did not even bother trying resetting the car computers to see if the errors were real or not. I paid them extra to physically inspect the harnesses and all they did was to run a check on Consult 3.

Hopefully you paid them by credit card, (always, always use a card), and now you can dispute the dealership's entire bill.

In the US, when you file a dispute with your credit card company, be sure to mention the FTC, Federal Trade Commission, and the FCBA, Fair Credit Billing Act of 1974 and tell them that the charges were fraudulent, fraudulent being the important keyword, do not fail to use it or your credit card company may be hesitant to work with you. They don't like to be involved and often try to put it back on the cardholder to resolve the matter. Hopefully, Mexico has similar protections.

I've had dealerships try to pull similar flagrant malpractice stunts with me over the years and have always prevailed. I also do not hesitate to file a lawsuit, if necessary, when companies try to screw me. Hopefully they'll think twice in the future before covering their incompetence at the expense of their customers.

 

[MikeinPA]

I then plug the car into my 240V home charger and it starts charging right away. 4 hours later the battery is at 100% with 9mV difference between cells.

I love it when things work out. So the QC PDM will work on non-QC vehicle with no modifications? That is very useful to know. The nonQC PDMs run around 4k, and the QC PDM are about half that.

Thanks!

 

[Dala]

So the QC PDM will work on non-QC vehicle with no modifications? That is very useful to know. The nonQC PDMs run around 4k, and the QC PDM are about half that.

Thanks!

That is correct. You can even enable the QC functionality by adding a few wires:

Glad it got solved @moonhack !

 

[moonhack]

Well, only a few days later I'm back with a new problem.

The car was finally charging and driving fine, but two days ago my dad thought about using the radio on accessory mode until the car shut itself down, right after charging the HV battery to 100% and unplugging the car... then yesterday we tried to turn it on and the EV system warning plus the turtle mode lights turned on, as well as the red low 12V battery light... I thought immediately about plugging it to charge, but there was no beep, no dashboard lights, no green "plugged in" light, nothing, just the "flick" sound that something makes inside the port after plugging it in.

I tried rebooting the car several times, by disconnecting the 12V battery and connecting it back after several minutes, as per the usual method. But the EV system warning and turtle lights won't go away, and the car won't charge.

LeafSpy keeps showing 2 errors only: P3196 and U1000, specifically as follows:

>P3196-00 0B EV/HEV CAN Error EVC-274
>U1000-00 0B EV/HEV Can Comm Circuit
U1000-00 4E HV BATTERY CAN Comm Circuit
P3196-00 4E HV BATTERY CAN Error EVB-99

They cannot be cleared, even after repeated reboots.

I checked P3196 on the service manual, and it seems to be directly related to low 12V voltage. It says:
"When VCM detects an error signal that is received from PDM (Power Delivery Module) via CAN communication" and "Make sure that 12V battery voltage is 11 V or more."
Otherwise, if it's not that, it could be the PDM or VCM, according to the manual.

So I checked the 12V battery with a multimeter and it was falling from just over 12V to 11.6V when the car was turned on. Also, it was clearly not charging. As you know, this battery was already previously deeply discharged for a long time, then just the day before it was discharged as well. Then we know that the Leaf's 12v battery charging system isn't that good. So I took it again to Autozone to recharge. I couldn't get it replaced by warranty as they seem to have mistyped my phone number when I bought it.

Well, today I took the battery home, which according to them had been charged to 13.38V at that moment. As you can tell it wasn't topped to 14V or more. I installed it on the car, and nothing. The EV warning and turtle lights are still there. There still doesn't seem to be any reaction from the car when the charging cable is plugged in. I retried deleting codes with LeafSpy, rebooting many times, even using my other Leaf's known-good battery on the problematic car (that one actually showed less voltage on the multimeter than the bad battery), but nothing changed.

I tried requesting ECU versions via LeafSpy and to my surprise "CHARGER" does not show up anymore. Due to this, and the fact that there's absolutely no reaction from the car to plugging in the charger, except for that "flick" sound, it seems that there's an actual lack of power, or at least very important communication to the PDM.

I really don't think the PDM is dead again, as it had been charging fine just before that, the error did not show up immediately after charging, and my EVSE is well-protected against power surges. Plus, when it actually dies, it tends to be detected by the VCM, there are beeps when the charger is connected, but electrical problems are detected inside the PDM and charging is prohibited. But, what could it be then?

Is there any fuse or relay I could check? Maybe the PDM harness has a faulty connection with intermittent issues? Is the whole car so sensible to low 12V power that now I need a brand new battery charged up to 14V to get the PDM to work? But if so, then how does my other Leaf work perfectly with seemingly less voltage? Maybe something triggered somewhere and needs to be reset physically?

The case is open again. Any help will be appreciated.

 

[nlspace]

When the pack is Full, then it will not charge.

An old weak or worn out 12V battery can cause a multitude of faults. If it had been depleted earlier, then again recently, well it is likely no good. It might appear to take a charge but has no capacity and lays down under load.

And the 11 volts in the FSM is carried over from ICE car manuals. An EV can't tolerate a low voltage supply to the numerous ECUs, plus the CAN buss.

It's possible for a low 12V battery to fail during driving or charging and cause secondary damage that "bricks" the car.

 

[moonhack]

When the pack is Full, then it will not charge.

Thanks for the insight. The thing is that by this point the battery is already at 80% since I drove to the Autozone hoping to have the battery replaced... and the car should at the very least beep when plugging in the cable, or show the green "plugged in" light, but none of that happens.

What I find weird is that even with a known-good battery from my other Leaf the problem persists and the codes won't clear. Why could that be?

 

[nlspace]

So the car starts to READY and drives okay, but it won't charge?

Do the DTCs still show up with the CAN buss fault as the error codes?

CAN errors can't be cleared; they will clear on their own once the buss is back up and working properly. This must be a localized vs widespread panic CAN failure or else the car would not go to READY.

There are 12V power lines into the PDM for the OBC, one is hot all the time and the other is switched on to enable charging. There are little fuses on the control board for these 12V feeds--maybe a fuse has blown?

The 12V is used to create secondary LV supplies for the control board, e.g. 3.3V, 5V, 16V, etc. The CAN buss controller chips need these LV supplies in order to function.

Maybe there is some other reason for your issue, and hopefully the DTCs will help reveal some clues.