Yellow dashed line leads to bricking

[JoelH]

Didn't see any threads discussing kind of thing, so here we go....

I charged my car (May 2017 Model S 75D, AP2, MCU1) at the ChargePoint station at work last Tuesday. When I went to move the car after the charge was done (~90%), I noticed a yellow dashed line on the power meter on the energy out side (I'm used to seeing it on the regen side due to low temps or full-ish battery, but never had seen it on the power out side).
Four hours later when I drove home, it was still there and I was limited to 50kw of power. Made it home fine, but not much fun driving with NO pickup at all). On the way home I made an service appointment to have this looked at, as what I was able to find on this issue talked about it being related to high temps. Temps were not high that day (South SF Bay Area).

That night I charged again with my Tesla HPWC up to 95% (was getting ready for possible PG&E blackout). The next morning the yellow dashed line was there, but now letting me use 100kw. A step in the right direction I thought...

Here's where it gets "fun".....

As I made my way to work Wednesday morning, the yellow dashed line was dancing around a bit, with the power limit varying from ~125kw down to 50kw. Then about 5 miles way from work (and 1/2 mile away from the service ctr, coincidentally), it starts to creep down closer and closer to zero. Seeing this trend, I start to divert to the service center. But I didn't make it, as soon the yellow dashed line grew all the way to 0kw and then I got a message that the car was shutting down. One call to Tesla Emergency Roadside Support, and 1 hour blocking traffic, and one tow truck later, and the car is at the service center. I never lost either display and never received any 12v battery warnings. The range still said I had 220 miles.

6 days later and the car is still at the service center and they seem to have no idea what's going on with it.

Anyone have something similar happen? Any ideas what might be going on?

 

[JoelH]

Here’s some shots of the power meter as this played out:

 

[meomyo]

let us know that the sc said....maybe 12v battery?

 

[OrbiterTI4]

I have had the "high power restriction" before, but only in the situation described by the owner's manual - it was below freezing and the battery was running low on charge. Good luck resolving this scenario.

 

[ucmndd]

Looks a lot like the HV battery dying to me.

 

[Bballou]

Maybe a failure of the battery cooling system?

 

[JoelH]

Looks a lot like the HV battery dying to me.

Maybe a failure of the battery cooling system?

Yes, these are the two main culprits I had in mind as well.

 

[JoelH]

Today makes 2 weeks that my car has been in the SC with this issue. Fortunately I got a loaner Model S last week.
"Still undergoing diagnostic testing" is what I get from my service adviser. Anyone else ever have a problem take this long to diagnose?

 

[jayman]

Am I the only one who read the title and thought this was on autopilot? I almost started avoiding all yellow lines. Good thing I read the posts! Good luck though.

 

[BigNick]

I'm thinking that the contactors, or an inter-module connection in the main HV pack are failing causing high resistance (and therefore heat) and the cooling system just can't keep up, so the car continued to reduce power until shutdown was the only option.

 

[Zishan]

I saw the exact same thing Monday morning. I thought maybe due to the low temps, got a little chilly here.

Drove for a few minutes and then finally noticed car was in Valet mode. I was playing around with the app the night before. Had to park and then disable Valet from my app, might be able to do this in car.

Long shot, but I can't see the center of your gauge cluster, where is would say "Valet."

 

[kg7jo-]

I saw the exact same thing Monday morning. I thought maybe due to the low temps, got a little chilly here.

Drove for a few minutes and then finally noticed car was in Valet mode. I was playing around with the app the night before. Had to park and then disable Valet from my app, might be able to do this in car.

Long shot, but I can't see the center of your gauge cluster, where is would say "Valet."

Exact same thing? your car also shut down in the middle of the road? I don't think Valet mode will do that. just saying...

 

[3ry-reset]

I've had this for more than a year but not to 0kW yet - Power limited only at 80+ mph

Tesla finally told me it was a failing battery but since it still retains capacity they won't repair it. I'm down about 100 horsepower right now and my P85 doesn't feel like as much of a Performance car any more.

I was able to determine it is the #9 BMB (out of 16) in my battery by using dev mode's BMS display, it shows that brick outputs almost a half volt lower than the rest of the pack for me now, one of your battery's modules must be completely dead to not just limit power but be totally unable to move.

 

[Zishan]

Exact same thing? your car also shut down in the middle of the road? I don't think Valet mode will do that. just saying...

Yes, I "saw" the exact same thing. Meaning the same dotted lines on my gauge cluster. Just saying..

 

[JoelH]

I've had this for more than a year but not to 0kW yet - Power limited only at 80+ mph

Tesla finally told me it was a failing battery but since it still retains capacity they won't repair it. I'm down about 100 horsepower right now and my P85 doesn't feel like as much of a Performance car any more.

I was able to determine it is the #9 BMB (out of 16) in my battery by using dev mode's BMS display, it shows that brick outputs almost a half volt lower than the rest of the pack for me now, one of your battery's modules must be completely dead to not just limit power but be totally unable to move.

Interesting. One difference I see with my situation, is that mine was not related to speed - it's a hard power restriction, regardless of speed. AND, of course it ended up shutting down the car completely . I'll be sure to update the thread here with the resolution.
I'm scared to death that they'll say "OK, it runs now - not sure what happened. Have a nice day"

 

[3ry-reset]

Mine started out only being there at higher speeds with speed but now it's every drive. I think it might be temperature related, it gets bigger when the battery is warm and smaller with slower driving but it's steadily gotten worse - just not as fast as yours. The actual problem isn't just temperature though, since voltage is measurably different in my single failed module.

I just wish Tesla would repair the pack since they've already told me needs repair.

 

[3ry-reset]

I should add Tesla replaced 3 coolant pumps with newer revisions in my battery during the same visit they told me the pack was failing so they probably think it can be kept alive a little longer to survive the warranty period too. One had just been replaced over the same issue, it was 100% failed but Tesla couldn't detect any problems - maybe that was what caused the module to fail. The other pumps were fine but older revisions.

 

[JoelH]

Today's update says the engineers think it's CAN issue. Think that means some kind of wiring or signal issue?

 

[3ry-reset]

CAN means it's intentional data in your car, it's the network that the car uses to communicate between its pieces. CAN is how AP steers the car, for example, by sending steering input control data to the steering motor. Everything is CAN. If they think it's a CAN issue it means something in your car is telling it to limit power to zero, that data can't be faked but there can be something broken sending an incorrect signal.

 

[JoelH]

My car is still at the SC :-( Will be three weeks tomorrow.

Latest area of interest is "the high voltage system cables between the drive unit and the master charger"

Two questions for anyone who cares to answer:
1) any insight on the above area of interest? Could they be looking for a damaged cable, or loose connector, or...?
2) has anyone had a problem that's taken this long to diagnose?