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P85D Lost power on road, "Pull over safely"

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wk057

Former Tesla Tinkerer
Feb 23, 2014
6,499
17,123
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So, I was setting out on a late day trip to get a few things done. Maybe ~125 miles of driving planned. I also was planning to stop and try out the new CHAdeMO adapter since I would be within ~5 miles of a station.

Anyway, car was acting a little oddly. Since the .167 update, during very light acceleration up to highway speeds I would feel a shudder from the rear somewhere between 30-40 MPH about 30% of the time. Was inconsistent enough that I chalked it up to something with torque sleep that needs tweaking and I was going to write Tesla about it tonight when I got back. This happened ~4 times today.

Was heading down a 45 MPH road at about 57. Had the cruise set. No cars in front. Was taking a very slight curve in the road and the cruise disengaged by itself. No errors or anything, just as if I had tapped the brake or something. Hmm... so I resumed it and it went back to work.

Less than half a mile later I disengaged cruise to regen to a stop to make a left at a light. A couple of seconds into that and I got this dreaded message:
2015-02-22 18.03.11-1920.jpg


No other alerts showing either, just this one.

Pretty sure I heard the contactors open (under light regen, was slightly downhill at the time) (Edit: Looking at my picture above more closely I see slight power draw from what I'd assume was the cabin heater... so maybe they didn't open?), car lost propulsion and regen immediately and behaved as if it were in neutral. I was going about 40 MPH at the time, and in this case I actually started to accelerate since I was initially using regen to slow for my upcoming left turn on the downhill. Last second I decided the left turn lane was not where I wanted to be without power, so I cut across to the right turn lane which was a bit larger of an area to stop safely.

Parked in the picture above. Took a couple of pics. Called Tesla roadside/tech support (877-79-TESLA). Surprisingly was about 8 minutes to get someone on the line. While I was waiting I had gotten out of the car and was just pacing around aimlessly (I tend to do that when on the phone). My fiance was inside waiting. About 5 minutes into the hold time I heard the contactors close while standing outside the car.

"Interesting," I said aloud to myself.

I hopped back in, still on hold (~6 minutes). Car was fine. Started, put it in drive, and set course for home.

Tesla rep got on the line right after this, and I explained everything to him. He was a little confused initially when I told him I was driving home.

Long story short, he didn't have any immediate information. After asking multiple times if I felt safe driving home he put in a request for service to look at it and get back to me.

Car made it home with no other errors or the shudder from the rear I had experienced prior. I decided to put off my errands until tomorrow, however, just to be safe.

All of that said, I'm both concerned and relieved. Concerned because I have no real idea what the actual issue is/was. If I had to throw out a guess I'd say it has something to do with the latest update. Relieved because the car cleared the error on it's own and I was able to drive back home without needing a flatbed trip.

Hopefully they figure it out, because I'm probably not driving it again until I get at least a cause nailed down by Tesla.
 
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Pretty sure I heard the contactors open (under light regen, was slightly downhill at the time) (Edit: Looking at my picture above more closely I see slight power draw from what I'd assume was the cabin heater... so maybe they didn't open?)... About 5 minutes into the hold time I heard the contactors close while standing outside the car.

I've read about the "contactors" and problems with them in other threads but don't really understand what they are, or what they do. Can someone please explain it? What does it sound like when they open and close and when does that happen?

Good luck in getting it diagnosed, WK057. I wouldn't want to drive it either until I knew the problem was determined and solved.
 
Very sorry to hear about this. I also felt a shudder once today since upgrading to .167 last night.
I really hope this isn't a widespread issue, and if it is, that it can be correct by another software/firmware update.
Please do keep us posted on what, if anything, Tesla finds from your incident.
 
I've read about the "contactors" and problems with them in other threads but don't really understand what they are, or what they do. Can someone please explain it? What does it sound like when they open and close and when does that happen?

Good luck in getting it diagnosed, WK057. I wouldn't want to drive it either until I knew the problem was determined and solved.

The contactors are a pair of high voltage relays that separate the high voltage battery from everything else. When they are open, there is no 400V power outside of the battery pack itself (and thus no propulsion power.) It's a safety feature - the computers have to make sure everything is safe before they close the contactors to allow power to flow.

Most of the time the contactors opening is a symptom/side effect rather than the problem itself - they need to figure out what the computers saw that led to them deciding the contactors needed to be opened for safety (or diagnose the 12V power problem that caused them to be opened even though the computer didn't command it, though that seems unlikely in this particular case.)
Walter
 
Most of the time the contactors opening is a symptom/side effect rather than the problem itself - they need to figure out what the computers saw that led to them deciding the contactors needed to be opened for safety (or diagnose the 12V power problem that caused them to be opened even though the computer didn't command it, though that seems unlikely in this particular case.)
Walter

Actually the contactors themselves are most often the culprit. That's why Tesla is proactively replacing older ones with a newer gen that it believes to be more reliable. Thought this issue had been resolved in the D models.
 
Actually the contactors themselves are most often the culprit. That's why Tesla is proactively replacing older ones with a newer gen that it believes to be more reliable. Thought this issue had been resolved in the D models.

I don't know much about the contactors issues, or the contactors at all really. But it sounded like wk057 thought it was probably a software issue related to the new firmware version. And correct me if I'm mistaken, but if it was something like the old contactor issue that you refer to, that you thought was corrected in the D models, wouldn't it not have resolved itself the way it did? I'll reword that. Doesn't the fact that the problem resolved itself mean that it wasn't a hardware problem with the contactors themselves, but rather a software problem?
 
Car needs service, power reduced

Shortly after getting version 6.1....167 installed I had to go out for about 1 1/2 hours or so. I didn't really notice anything different or unusual though I was wondering if one of the motors was making a higher whine than normal (probably the front). Just as I was approaching my home I got an alert to say that the car needs service and the power was reduced. I did do one 1/2 launch shortly before the problem occurred (just aggressive throttle really).

I was wondering if one of the motors had been shutdown but the person I talked to in technical support seemed skeptical as there were no other log messages. I didn't really notice the reduced power though I was taking it easy; however, if the front motor had been shut down presumably I wouldn't notice unless I did a launch or something.
After I got home I talked to Tesla support who referred ithe problem to the vancouver service center.

I decided to see what would happen with a reboot but in fact by the time I got back into my car the message had cleared. I rebooted the main screen and then drove around my neighborhood for a bit with no further ill effects.

Maybe I discovered the new "Torque coma" feature?​
 
Have a P85D.
Updated to the new FW (.167)
Had the same / similar issue.
After the update, I was driving it for about 15+ mins and a cryptic message came up on the screen. (Car needs service, power reduced)
It was Sunday, the service center wasn't open so I called and left a message about the issue because this is my primary driver.

I decided to reboot the main screen (middle buttons) and after the reboot I took the car out for a 10+ min drive and the issue didn't come back.

I did get a call from a Tesla Service rep about the issue and she asked if I did a reboot on the car, I said yes, and she asked if the problem went away and I said "so far"
She said, this was a known issue with the new FW they pushed, I told her they should probably document this.

So I'm hoping its gone away and doesn't rear its head again.
 
Follow up...
i got a call from the Vancouver service center who told me that there might be a temperature issue and they wanted to check a few possible causes including a possible kinked coolant hose. They had a ranger about 150 miles away who was willing to come and meet me, even though I was at a movie by the time the technician arrived. The technician met me in a mall parking lot where it was -7C, (20F) and he took apart the car and checked a few things that had been suggested. Unfortunately/fortunately nothing was found so he left me (the car was fine at that point).
About an hour later, after driving around he city, the message came back again. Once again it was cleared simply by shutting down the car and getting out.
I've reported this reoccurrence and I'll await their suggestions. In the meantime I haven't suffered any noticeable loss of driving and today I had no further warnings during some spirited driving.

- - - Updated - - -

Have a P85D.
Updated to the new FW (.167)
Had the same / similar issue.
After the update, I was driving it for about 15+ mins and a cryptic message came up on the screen. (Car needs service, power reduced)
It was Sunday, the service center wasn't open so I called and left a message about the issue because this is my primary driver.

I decided to reboot the main screen (middle buttons) and after the reboot I took the car out for a 10+ min drive and the issue didn't come back.

I did get a call from a Tesla Service rep about the issue and she asked if I did a reboot on the car, I said yes, and she asked if the problem went away and I said "so far"
She said, this was a known issue with the new FW they pushed, I told her they should probably document this.

So I'm hoping its gone away and doesn't rear its head again.
Funnily enough yesterday my technician had not been told about .167 and did not have it on his laptop. Of course I mentioned that I had just installed the new update so maybe things have moved on since then.
(btw, my license plate reads AMPED)
 
Doesn't the fact that the problem resolved itself mean that it wasn't a hardware problem with the contactors themselves, but rather a software problem?

This is likely not going to lead to contactor replacement. There's been a lot discussion about it in the context of this thread tho. Hence my comment.

Actually, a number of owners have been able to limp into a SvC even after having the contactors open under load. Or it has been noted that they become "unstuck" after a while. Never had this issue so can't say for sure. Just based on what I've read here.
 
Same thing happened to me today (P85D with .167 update from last night), and it resulted in a particularly dangerous situation. Was going thru some uphill twisties where you lose sight of cars in front/behind you every 3 to 5 car lengths. Came around a right-hand turn and heard "beep-beep-beep", which I had only heard before when the "early collision warning" alarm went off. A moment later I got "car needs service" and all power disappeared underfoot -- I was left stranded on the uphill side of a blind curve with no power available at all.

Very scary as I sat there trying to figure out what to do -- pulled over as far as I could in the 10 feet of coasting I had remaining before coming to a standstill, but was still sticking out 2/3rds in the road (since there was no shoulder), and put my hazard lights on. Just then I saw a large truck come up behind me emerging from the blind curve -- fortunately he wasn't going that fast -- so I honked to be sure he saw me. After he passed, I decided to put the car in Reverse, then into Drive again, and luckily power was restored and I was able to drive out of there.

Whole incident probably lasted 45 seconds, but I was scared sh**less.

One other thing -- at one other point in the drive I felt something funny -- a "lurch" when traveling downhill that caused the car to lose speed for a moment -- then all continued as normal.

I called Tesla Service and they said they pulled the logs and forwarded to a service advisor, who is to call me tomorrow.

For anyone else who this has happened to, was there a "3 beeps" audio alert associated with your power shutdown? Or was what I heard an indication that collision warning system thought that hillside next to me was another car? (Just trying to figure out if "early warning detection" is correlated with "power shutdown" in .167)

Needless to say, this is an awfully bad bug to instantly lose all power when traveling at speed, and could have resulted in serious injury. This incident has shaken my faith in Tesla QA and the pace with which they are updating software for the D.

-- David
 
Same thing happened to me today (P85D with .167 update from last night), and it resulted in a particularly dangerous situation. Was going thru some uphill twisties where you lose sight of cars in front/behind you every 3 to 5 car lengths. Came around a right-hand turn and heard "beep-beep-beep", which I had only heard before when the "early collision warning" alarm went off. A moment later I got "car needs service" and all power disappeared underfoot -- I was left stranded on the uphill side of a blind curve with no power available at all.

Very scary as I sat there trying to figure out what to do -- pulled over as far as I could in the 10 feet of coasting I had remaining before coming to a standstill, but was still sticking out 2/3rds in the road (since there was no shoulder), and put my hazard lights on. Just then I saw a large truck come up behind me emerging from the blind curve -- fortunately he wasn't going that fast -- so I honked to be sure he saw me. After he passed, I decided to put the car in Reverse, then into Drive again, and luckily power was restored and I was able to drive out of there.

Whole incident probably lasted 45 seconds, but I was scared sh**less.

One other thing -- at one other point in the drive I felt something funny -- a "lurch" when traveling downhill that caused the car to lose speed for a moment -- then all continued as normal.

I called Tesla Service and they said they pulled the logs and forwarded to a service advisor, who is to call me tomorrow.

For anyone else who this has happened to, was there a "3 beeps" audio alert associated with your power shutdown? Or was what I heard an indication that collision warning system thought that hillside next to me was another car? (Just trying to figure out if "early warning detection" is correlated with "power shutdown" in .167)

Needless to say, this is an awfully bad bug to instantly lose all power when traveling at speed, and could have resulted in serious injury. This incident has shaken my faith in Tesla QA and the pace with which they are updating software for the D.

-- David
This sounds more like wk057s problem but I wonder if these issues are related. In my case I didn't lose power completely, just had it reduced.
 
Was the normal 3 beep notification that happens any time an alert pops up, even something like "Door open" when in drive. Same noise.
Luckily in my situation there was virtually no traffic on the road I was on.

The lurch you mention is probably what I was describing as a shudder in my thread. Happened a few times before the loss of power in the ~16 miles prior.
 
FWIW, I talked to Cindy at the Palo Alto store / service center.
I should probably make an appointment anyways since I need to have my right small window fixed since air is seeping in through there.
Hopefully this issue doesn't come back or they push a new bug fix for it soon.
I love the concept of OTAs, don't enjoy driving beta software that can cause this kind of issue.

Same thing happened to me today (P85D with .167 update from last night), and it resulted in a particularly dangerous situation. Was going thru some uphill twisties where you lose sight of cars in front/behind you every 3 to 5 car lengths. Came around a right-hand turn and heard "beep-beep-beep", which I had only heard before when the "early collision warning" alarm went off. A moment later I got "car needs service" and all power disappeared underfoot -- I was left stranded on the uphill side of a blind curve with no power available at all.

Very scary as I sat there trying to figure out what to do -- pulled over as far as I could in the 10 feet of coasting I had remaining before coming to a standstill, but was still sticking out 2/3rds in the road (since there was no shoulder), and put my hazard lights on. Just then I saw a large truck come up behind me emerging from the blind curve -- fortunately he wasn't going that fast -- so I honked to be sure he saw me. After he passed, I decided to put the car in Reverse, then into Drive again, and luckily power was restored and I was able to drive out of there.

Whole incident probably lasted 45 seconds, but I was scared sh**less.

One other thing -- at one other point in the drive I felt something funny -- a "lurch" when traveling downhill that caused the car to lose speed for a moment -- then all continued as normal.

I called Tesla Service and they said they pulled the logs and forwarded to a service advisor, who is to call me tomorrow.

For anyone else who this has happened to, was there a "3 beeps" audio alert associated with your power shutdown? Or was what I heard an indication that collision warning system thought that hillside next to me was another car? (Just trying to figure out if "early warning detection" is correlated with "power shutdown" in .167)

Needless to say, this is an awfully bad bug to instantly lose all power when traveling at speed, and could have resulted in serious injury. This incident has shaken my faith in Tesla QA and the pace with which they are updating software for the D.

-- David