New Problem

[Doug_G]

Got my car back from service yesterday. A firmware update installed last night.

Start the car this afternoon. Got:

Cruise Control Disabled.

Weird.

Had to leave for Xmas dinner. Tapped the throttle.

Both Pedals Pressed.

Uh, no they're not.

Hmm brake lights are stuck on. Constant beep beep beep while driving.

Supposed to go on a road trip tomorrow. Brilliant timing.

 

[Dakkor]

Look like brakes are stuck or something.. or E-brake? Weird.

 

[meloccom]

Sounds like the brake pedal sensor has failed or got knocked loose during service.
Shine a flash light up under the dash, it might be something simple, or not.

 

[dj905]

Hi Doug,

Sorry to hear about your problem. I had something similar happen last winter... my brake lights were stuck on, and my car would not start up properly. In my case, it was complaining about not being able to find the key as well. This happened after a drive during a particularly slushy period.

Bottom line is that I left the car in the garage overnight and the problem went away - never to return. The service centre investigated and thought that it was possible that the Body Control Module (BCM) got damp. I believe that it is located near the passenger footwell.

I hope that you are able to get the problem resolved... or you will have to take the roadster on your trip ;-)

Best wishes to you and your family for a Merry Christmas and Happy New Year,

David

 

[Doug_G]

Thanks David that's good info.

I have reasons to suspect the brake light switch. It turns out if you don't touch the brakes for a while it turns off.

Doesn't explain the cruise control message though. So maybe the module is the problem.

On the other hand, maybe I got a wrong firmware build last night. Timing is coincidental...

 

[mrElbe]

Cruise control gets disengaged when brake light goes on. Looks like brake pedal switch problem. Have you tried pulling up the brake pedal with your toes underneath?

 

[Doug_G]

Yes, it's not the pedal.

 

[Doug_G]

David, I think your experience has just repeated. I left the car sitting for five hours and the problems have disappeared.

 

[number12]

Did you reset both ways?

 

[Doug_G]

Yes, first thing I did was reset both.

The problem is intermittent it seems. Comes and goes.

 

[Doug_G]

Well I decided to go ahead and take it to Toronto. No brake warning issues yet, but after 45 minutes the cruise control failed again. Supecharging at the moment...

 

[dj905]

Well I decided to go ahead and take it to Toronto. No brake warning issues yet, but after 45 minutes the cruise control failed again. Supecharging at the moment...

Doug, I'm glad to hear that the problem cleared up. I hope that everything has been ok with your trip. Let us know if you discover anything further.

David

 

[Doug_G]

After the supercharger the problem did not recur. Never mind autopilot... it was nice just to have cruise control.

 

[Doug_G]

Happened again. Was just driving on the 401 and the cruise control failed. Brake lights on, both pedal pressed message. Lasted maybe 20 seconds. Have to shut down car toget cruise back.

Annoying mostly, but brake lights stuck on is a sadety issue. Fortunately it isn't doing it that often now.

 

[Doug_G]

Made it back. At one point the brake lights stuck on for 20 minutes... fortunately the traffic was light by that point. It disabled stability control and traction control that time. Fortunately the roads were dry (in fact we scurried home to avoid the incoming freezing rain storm).

 

[Doug_G]

They're coming to get the car tomorrow. Really annoying to drive around with constant BEEP BEEP BEEP "Both Pedals Pressed". Never mind that the brake lights are stuck on.

Seems to happen much less often if the cabin is toasty warm. If it's cold the problem is constant.

 

[Doug_G]

So this just gets funnier. I had a loaner car over the holidays. Tesla tells me that they fixed it, and my car will be coming back today.

Then I got the Service Invoice. It says they replaced the brake pedal switch. Personally I would have bet it was an electronics module or something rather than the switch - if it happens on power-up it instantly displays "Cruise Control Disabled" while my foot is still on the brake. How can it know there is anything wrong with the switch at that point? Reading further I see they they couldn't reproduce the problem. Uh oh. Speaking as an engineer who has been around this loop many times in my career... I hate intermittent problems!!!

Sure enough, a few hours later the driver is rolling the car off the truck and I can already hear BRAP BRAP BRAP! BRAP BRAP BRAP! Yep, wasn't the switch. Please roll it back on the truck, thanks!



Meanwhile the loaner has a bad ground somewhere, and keeps making random error messages that instantly disappear again. Service offers to replace it with an Enterprise, but that's okay... I'd rather drive the Tesla!

My sympathies to Service. This car is being cantankerous!

 

[green1]

Intermittent problems are always a royal pain.

However I also have limited patience for technicians that make obviously wrong guesses based on the available information in these cases (such as the pedal switch when it happens before it can know that's an issue) If they get the wrong module, that's understandable, but when they change something that really can't be the issue?

I have had a supervisory role with technicians doing troubleshooting in the past (not on cars) and there were many times where I'd look at one and say "do you want to re-think that?" based on similar such things. Too often someone will replace the easiest part to change, rather than the one most likely to be causing the problem.

 

[Doug_G]

Well I'm sure they're doing their best. They apparently weren't able to reproduce the problem for whatever reason. That makes it a lot more difficult.

I suggested that it seems to happen more often when the car is cold soaked. So they left it outdoors for two days and it still didn't do it. Go figure! The car is being perverse.

As for the precise pattern of the symptoms... I doubt they considered my input as authoritative, and may not have actually gotten all the details I passed along. Very few of their customers are engineers experienced in debugging complex systems...

 

[S'toon]

Well I'm sure they're doing their best. They apparently weren't able to reproduce the problem for whatever reason. That makes it a lot more difficult.

I suggested that it seems to happen more often when the car is cold soaked. So they left it outdoors for two days and it still didn't do it. Go figure! The car is being perverse.

As for the precise pattern of the symptoms... I doubt they considered my input as authoritative, and may not have actually gotten all the details I passed along. Very few of their customers are engineers experienced in debugging complex systems...

They should have shipped it to SK. -34 when I went out to get groceries after breakfast today. Coldest place in Canada this morning.