Brought car in for annual, had fan/blower cleaned, it stopped running, overheated and now PEM dead

[MileHighMotoring]

This sounds like the fan connector on the bottom of the PEM. The contacts are marginal at best, and if they aren't mated really well, they will burn (oxidize) and make even less contact (in a downward spiral) to the point that the PEM complains. In my case, this was associated with "Drive Train Service Required" messages on the VDS, and errors 1144 and 1146 in the logs. If you have those, that's the issue.

The unfortunate thing is that once the contacts are burned, they need replacement. The cable end (going to the fans) is relatively easy and cheap, but the connector on the PEM is not considered a repairable item at the SC. We ended up working with the factory to swap for a remanufactured PEM. I paid for the labor ($800-ish), and the cost of the connectors themselves (I think it was a few bucks). You might have your SC contact the Rocklin, California SC for guidance on this. If the contacts burned because the technician didn't seat the connector properly (to be clear, not the cause in my case), you even might argue that they pick up the whole cost of the repair.

There's a thread from my saga: Error code #1111? (My roadster is still needy) and also another one by another victim here: #1146 DMC Motor Fan Problem?. I think there are others too...

Good luck!

Greg.

Greg, you're a hero. Honestly, go get yourself a g.d. cape. I'm buying.

I mentioned this to the manager and while it took nearly a month to get it all done, they were able to replace the tiny part inside the connector and charged me $840 in labor only.

 

[gregd]

YEA! Glad I could help!

 

[wiztecy]

I mentioned this to the manager and while it took nearly a month to get it all done, they were able to replace the tiny part inside the connector and charged me $840 in labor only.

Does anyone know why this connector keeps frying? Has anyone reported this issue on a 1.5? I haven't seen it... Odd that it keeps popping up and if owners (2.x?) can prevent this from happening in the future.

 

[ML Auto]

Does anyone know why this connector keeps frying? Has anyone reported this issue on a 1.5? I haven't seen it... Odd that it keeps popping up and if owners (2.x?) can prevent this from happening in the future.

Probably due to the fact that you have to unplug it every time you do a PEM cleaning, which as you always point out is a lot more on the 2.0 - 2.5.

 

[wiztecy]

I would think all versions would be on schedule for their annual's / cleaning. Unless the Roadster's that are failing have been in for multiple annuals / year due to customer complaints of elevated PEM temps and/or poor performance. Tesla pulls the 1.5 PEMS off and hits them with compressed air which I'm sure barely anything comes out, so I'd think the removal of that connector would be stressed just as much. Plus most of the 1.5's have had more annuals than the 2.x's due to their earlier build and delivery dates so I'd expect the 1.5's to go out first. Again, with samples there's more 2.x's out there so statistically you'd see those more often. But I would think at least one 1.5 would of exhibited the issue if the same connector is being used. Otherwise why is it building up resistance there at the connector? Possibly the 2.x is pushing more current. I know from the 2.0 I drove the PEM blower was howling when it was pushed to do its job, was impressed. I forget if that one motor dual blower below is howling or the fan inside the PEM. Tesla surely are putting more juice to get that fan spinning so its definitely pushing more current.

 

[gregd]

The 2.0 fan upgrade was my thought too for a contributing factor.. Presumably a bigger motor (anybody have the specs?) for the net higher airflow, but no change in the connector. So, it's probably marginal to begin with, and then with an at least yearly disconnect / reconnect cycle, after a few years it's shot.

 

[PV-EV]

I had the blower connector at the PEM fry in my 2.5 with the upgraded blower motor. If I remember correctly the new fan pulls 45 amps on startup and 15 amps when running. The original pulled 22 amps on startup and 12 amps running. The Molex connector is rated for 18 amps. Pretty marginal setup IMHO. Not to mention that the wires to the blower seem pretty small. The plating on the connector might not hold up well to wear and tear and/or the spring mechanism of the female pins gets weak. The connectors are only rated for 25 matings. Mine failed after about 8. Fortunately you can buy just the female pins for about $2 each and replace them yourself but you have to do this before burning up the connector on the PEM side, which is a circuit board right angle header. The parts are readily available. I suspect that a lot of PEM failures can be traced to the failure of this one part.

 

[adiggs]

I had the blower connector at the PEM fry in my 2.5 with the upgraded blower motor. If I remember correctly the new fan pulls 45 amps on startup and 15 amps when running. The original pulled 22 amps on startup and 12 amps running. The Molex connector is rated for 18 amps. Pretty marginal setup IMHO. Not to mention that the wires to the blower seem pretty small. The plating on the connector might not hold up well to wear and tear and/or the spring mechanism of the female pins gets weak. The connectors are only rated for 25 matings. Mine failed after about 8. Fortunately you can buy just the female pins for about $2 each and replace them yourself but you have to do this before burning up the connector on the PEM side, which is a circuit board right angle header. The parts are readily available. I suspect that a lot of PEM failures can be traced to the failure of this one part.

If I'm understanding your comment correctly (and I freely admit to having the data/software skill rather than a hardware / electrical engineering skill), and considering the larger context of many failures of a weak part / weak design, is there proactive maintenance that could be incorporated into the annual service to improve the reliability of that connector, and avoid the freakout and long repair windows that follow failure of the connection?

You mention the connectors being rated for 25 matings, with anecdotal evidence of more frequent failure. Maybe every 5th annual maintenance, proactively replace the connectors as part of the annual maintenance for a few extra $$ and minutes of labor. That sounds really cheap to me compared to thinking the PEM is fried, or even needing the $840 labor repair @MileHighMotoring had to go through (and the month of downtime).


I'm asking out of curiosity and to expand my own understanding. Also thinking ahead to my next annual service - it'll be #4 or #5 for my car and I'm wondering about proactive steps to avoid this problem entirely.

(I'm also wondering if this is the sort of thing that Tesla adds to the Roadster annual maintenance cycle - do this bit of proactive work every 5 years say).

 

[hcsharp]

I plan to use DeoxIT on those connectors every time I unplug them.

 

[gregd]

Great idea! I wonder if the service guys would do that if we asked nicely during our annual de-leafing of the drive train? Would that be something they would have in the service department, or should we bring our own?

 

[Mark77a]

I plan to use DeoxIT on those connectors every time I unplug them.

Good tip .. thanks > https://www.amazon.co.uk/dp/B003D8EA7A/ref=cm_cr_ryp_prd_ttl_sol_5 (and available in UK )

 

[skadax]

I'm glad you got this issue sorted out.

I had the exact same thing happen to me last year after annual service. Essentially same services done as you and about 1 week later I was driving the car and gave me the overheating message and stalled me in the middle of the road. I had it towed to Tesla as well and they concluded the PEM connector was the issue. They did not admit to any fault during the service but like you I find it very strange to consider this only a coincidence. They ended up replacing the PEM (with a remanufactured sport version on my otherwise base 2.0) as well as replacing the PEM fan. Luckily I was under CPO warranty still and this was all covered at their cost.

The fact that it happened to both of us in the exact same way, and I'm sure to others, makes me a little worried that the service techs are not entirely trained/being careful with this part of the annual service.

I'm just livid right now. I had the Roadster in for a $1,000+ annual service last month and had them clean the PEM fan, flush coolant, everything they recommended and more. I've driven the car only a few times, and the other day I drove one mile and got a warning that the car was overheating and it stopped, literally one mile. I had it towed to Tesla and they're saying the PEM and the fan assembly are both garbage and I need to spend $10,000 + labor (a few grand I assume). The car ran perfectly before the service. I find it impossible to consider it merely a coincidence that they worked on the PEM fan and it promptly died and killed the PEM.

Any ideas on how to handle this? Honestly I'm in shock right now. I want to scream, but the service reps at my service center aren't at fault so I can't blame them for relaying this to me. I need help. Any advice?

 

[int32_t]

I'd be tempted to replace that connector with something significantly stronger -- both mechanically and electrically. Solder a short pigtail directly to the PEM and run it outside to the larger, stronger connector. Secure with loads of hot glue as strain relief, or maybe find some holes to zip-tie the pigtail to.

Might save a lot of angst. (On the other hand, it might cause a little, too, if something goes wrong!)

 

[hcsharp]

Both solder and hot glue melt at the temperatures where you'd want to protect it, although if it was soldered it may not ever get very hot to begin with. It's protected with a 25A fuse. The connector could theoretically be replaced with a better one but you have to take the entire PEM apart to get access to it.

 

[PV-EV]

I soldered a pigtail onto my PEM much as you suggest and it has been working satisfactorily ever since. Heat shrink and tape provide strain relief. I agree with hcsharp that it would be a real job to dismantle the PEM enough to replace the male connector. To be properly repaired a person should upgrade the whole circuit, from PEM to blower, including the wire.

 

[MileHighMotoring]

Isn't the PEM dismantled to do the repair I just had done? So ... do this repair once, or do it every few years (potentially) ? Or am I misjudging what part was replaced?

 

[ML Auto]

The board with the fan connector is fairly easy to remove. Once the PEM cover is off the board comes out with a few connectors and bolts. You don't need to disassemble the PEM.
Here are some pics. The fan connector is the 4 pin one on the left.

 

[PV-EV]

Very nice info. Thanks for posting the pics. I picked up the right angle connector from digikey but chickened out on digging in that deep to replace it. Looks like a good project for the winter!

 

[dpeilow]

Now I've got the PEM fan issue as well. I mentioned to Tesla that I thought it was developing and on the first trip out after sorting the HVAC pressure issue now I get my first #1144 while charging last night.

The temps below were seen after some moderate 60 mph driving on the way back.

 

[dpeilow]

Here's a supplier for the PEM / Motor fan in the UK, if any out of warranty owners fancy doing a DIY swap. Looks like they also have the evaporator fans too.

Centrifugal Blowers - Ventilation


It's the double blower 12v SPAL fan, type 14-AP74/LL-22.

£99.36 + VAT, or £127.03 inclusive of VAT & Delivery.