new PDM, very strange issues

Had the PDM blow in a freak incident at a charging station about two weeks ago: parts of the QC?! circuit was burnt out, and the car had a permanent "EVSE plugged" status which basically disabled the car. It happened when we attempted to plug in to start the charge at public L2 charging station (weird how it affected the QC part....). Eventually had to be towed to the dealer, and got a new PDM replaced under warranty (whew). The replacement part was 292C0 3NF7D. While waiting for the tow I also noticed that the 12V was sitting low at 11.6 when the car was on, and since the battery was the original and *could* be on its last legs, I made a note to replace it ASAP.

It charged fine on the AV charger at Nissan, but during the very next L2 charge at a public station it ended abruptly at around 70% or so. After that, the car disabled itself when we attempted to leave (as we were pulling out of the parking spot, the EVSE plug status suddenly came on and car was suddenly disabled again). This time, re-connecting the 12V eventually cleared the status. I decided to replace the battery just in case. Since then we were able to drive normally, but charges at various stations would suddenly stop, and then for a while we wouldn't be able to charge. Did a close to full charge (97) on the AV charger at Nissan over the Christmas break and left it there.

On the 26 of December we took the car home from the dealer, and we did some short charges over the next few days on public stations (30 minutes each time), as well as a 30 minute quick charge without problem (other than being -25 and charge rates were super slow). We finally got our JuiceBox installed, and was able to do longer charges at home. This afternoon, we did another charge from 20% to about 80, and the charge again stopped abruptly. Trying to pull the car out of our driveway it suddenly disabled again with the EVSE plug light. This time since we were in our back yard, we had time to dig a bit further: the 12V battery was again sitting low at 11.6V according to LeafSpy, signalling that the 14V->13V startup routine didn't run. After we disconnected and reconnected the 12V, the voltage on the 12V went back to normal (starts off at 14.4, then goes down to 13V after a bit), and, as expected, the EVSE plugged status disappeared and the car was drivable again.

Anyone else seen anything like this before? Initially when considering the AV EVSE vs public chargers we thought it may have been the diode issue, but now it looks like something else completely since charging generally starts off fine on other chargers. Our current guestimate is that somehow the charger can randomly malfunction during a charge, and if it does, seem to crash the system in such a way that the 12V program gets messed up, and certain critical features in the car rely on the 12V having enough power (such as clearing/checking for the EVSE plug status). This is pure conjecture of course... also the 12V battery may be a complete red herring as we've left the old battery disconnected for quite a few days out in the cold and it's still reading 12.6V. Haven't load tested it yet, but it's *probably* still OK based on what we're seeing above with the new battery.

Will be bring it back to the dealer when they're open next on the 2nd of January, but at this point they're not really sure whats going on so any external points of reference could be helpful.

Thanks in advance!

addendum: No DTCs at all before or after the 12V disconnect and everything else looks normal expect for the 12V being at 11.6 when system is on (which indicates not charging from traction battery at all)

jt123 said:

addendum: No DTCs at all before or after the 12V disconnect and everything else looks normal expect for the 12V being at 11.6 when system is on (which indicates not charging from traction battery at all)

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I would measure current draw in conjunction with voltage decrease/ increase physically with a meter to the 12v system.
Accessory battery under voltage conditions definitely have caused a lot of various problems although non that I have read on this forum have been the culprit of any charging problems to this point.
Suspect charging algorithm of dc to dc converter or abnormal load on the 12v system .
Could also be a coolant circ problem ( I know ambient is cold} but circulation is needed during the charging cycle as the internal components can still overheat.

thanks!

yeah, at this point our guess is also something with the charging circuit. since its been super cold outside (-25 degrees C), if it doesn't cool properly there's a chance it would still work without overheating due to the ambient temperature. the time it stopped prematurely a few times before christmas was indeed when it was a bit warmer out (like, -10 degrees haha), and the most recent time it crapped out was after a long-ish charging session (10kWhr was added)

will be bringing it back to the dealer as soon as service opens again after the holidays.

update: today i found out that the coolant tank for the EV system was EMPTY. perhaps they forgot to fill it, perhaps it has a leak, but i've topped it up.

i heavily suspect there's a cooling issue going on. things are acting up more in the balmy -8C weather (as opposed to the nearly 2 weeks of -15C and below), and the car will even lose power while driving (this happened before adding back the coolant). putting in the coolant may have helped, but there's a chance its not circulating properly or something. charging still fails after a while and then the car has to sit with the 12V unplugged, but also now needs to rest otherwise the ready light will briefly come on and then off again, showing EVSE plugged or simply not able to get into Ready mode (but can go neutral in this case). maybe the water pump is toast after running empty for so long? leaving it for a while and coming back later: bam everything works normally until the next charging malfunction.

talking with the dealer has been super frustrating as they're clearly not interested in servicing the vehicle: first they were adamant that there wasn't such a thing as EV system warranty, and then after they fixed the issue they weren't certain that things were all clear (only replaced the fault that i came in for, which was the "EVSE plugged" status that was caused by a burnt out charging circuit). and now further charging related issues is now a "new problem" which i'd "probably" have to pay for. also there is definitely a lack of awareness regarding how the damn thing even works: they kept on insisting that if there was a coolant issue leading to overheating, there would be warning lights. but from what i can see the only temperature related issues pertain to the battery system. it's almost like they're encouraging us to just escalate the problem so that Nissan can deal with it higher up.

anyway, i've decided to taper off on doing troubleshooting for Nissan and we're currently pursuing legal options to push them firmer to just fix the issue, replace the vehicle, or just terminate the lease and reimburse us for the payments we made during the period that the car was malfunctioning.

the kia soul ev, with a much longer standard factory warranty and a few better design considerations, is starting to look more and more appealing...

Just keep in mind that the Soul EV has been showing battery degradation as bad as Nissan's.

Good to know! The redeeming factor for battery life here is that it’s cold for a large portion of the year. The 2014SL we have is sitting at 48000km and 96% SOH. For many Canadian Leafs even a 2011 that doesn’t have 10 or 11 bars is a cause for concern.

At this point we’re more concerned with the warranties available: the Leaf is about to run out on the EV system warranty and based on the repair experience while even under warranty, we really don’t want to deal with any out of warranty repairs... a fellow 2013 SV owner at the same dealer is facing a $3k AC repair out of pocket on a leased vehicle. Kia has substantially better basic and EV system warranties. Of cours the flipside is knowledge regarding the car overall is probably worse given how few of them there are compared to the Leaf...

Just sent out the paperwork for the legal warranty... will see how Nissan responds.

update: fixed!

intermittent short on a low voltage signal harness to the PDM, caused by some water that was freezing/thawing. cleaning out and reconnect seems to have solved it. (fingers crossed). how that water got in in the first place is something we're still not sure of (i have some theories), but because so much time and hassle has been spent by everyone involved, and we didn't end up paying through the nose for it, we're going to leave it at that as a satisfactory outcome dealing with Nissan overall.