Long road trip addition to your thread.
2021 MYLR, just bought lightly used with 11,000 miles 3 weeks ago. Went on a 2000-mile round trip getaway with the two kids, wife and gear last week. Denver area to western KY. Paid for 1 month of the FSD subscription to see how it does on such a long drive on I-70 through eastern CO, KS, MO, IL and KY. Some observations on phantom braking we experienced (often).
Current SW rev: 2023.12.5.4
1. Afternoon departure temp on May 26: 71 F, rain storm was chasing us on our way out, but it was sunny where we were heading.
2. Headed east on E-470 tollway, speed set on autosteer/navigate to 75 mph (speed limit is 75 mph).
3. Within 20 miles, first phantom event - hesitation and drop from 75 mph to 71 mph, then slowly back to 75. No cars near us, one car about 3/4 mile ahead. None behind us or beside us. We were traveling in the center lane of three lanes.
4. No more until I-70 east somewhere before Limon SC. No cars near us, cool temps in the 70s, no mirages, mostly cloudy. no overpasses, no shadows, good lighting, no wind. Phantom braking hammers everyone from 75 mph to 51, then gets to 60, drops again to 55, then slowly gets back up to 75. Bug report recorded on car. SOC was around 60% at this point.
5. Charged up to 72% at Limon, then off to Colby, KS.
6. Third phantom braking event near Kanorado (Kansas/CO state line) - not as severe, but noticeable. Drop to ~68 mph, then back to 75. Car was coming up on our left rear quickly. Some cars in the distance, and one about 1 mile back. Again, nothing was around. Disabled auto steer, switched to TACC cruise control only.
7. Made it to Colby with no events, then within 20 minutes of leaving Colby SC, another event, but on cruise control/TACC, not autosteer. Yet another bug report recorded on the mic.
8. Halfway between Hays (worst SC on I-70, by the way) and our stop for the night hotel in Salina, getting dark, still only on cruise control, another hard event. No cars near us yet again. Temp around 78 F.
9. Salina for the night.
10. Salina to KY - absolutely no phantom events on autosteer/navigate or cruise. Side note: Autosteer lane change on the FSD subscription absolutely sucks. Changes lanes to "faster lane" for no reason (I had it set to not wait for me to confirm and just change lanes, Mad Max setting). No cars in front of us or behind us. I let it do it's thing, and within 3 minutes it wants to exit the passing lane and does so, albeit not very smoothly - a slight drop / hesitation in speed and then it moves over, no cars anywhere behind us. Then within 1 minute, it wants to move BACK into the passing lane for no reason. This continued and many times I had to deny the lane change because it made no sense and in a couple of cases, was going to be pulling into an oncoming speeding car! So I turned all of this off and went to the regular lane change on my prompt, not the auto or suggested.
RETURN TRIP:
KY to Salina: NO phantom braking events. None. Temps in the low 90s, sunny, plenty of mirages, cars, and opportunities for some "fun" phantom braking through crazy traffic in St. Louis and KC (what is with drivers there, btw??). But nothing happened on autosteer/nav.
Salina to Denver:
1. Left early morning on a Monday, low traffic, sun behind us, temps around 64. Within 30 minutes our first phantom event. 80 mph to 71. I had decided this time to just let them happen and work through the entire "event" unless there were cars nearby, upon which time my plan was to disengage and take control.
2. Several more phantom events occurred for the next 4 hours, usually in very desolate parts of I-70 with very little traffic. There were mirages and some traffic here and there, and I switched in and out of cruise and the autosteer. Neither mattered - about 6-8 more events happened equally and some were within a few minutes of each other - varied from minor to WTF just happened (!!) braking.
3. Decided to tweak some things. Turned off Automatic Emergency Braking setting. No change - another event occurred about 45 minutes later.
4. Turned AEB back on, then turned off the FSD navigate on autosteer subscription setting, setting me to basic autopilot.
5. Drove from Limon to almost I-25 via I-70 and E-470 highways on both CC and autopilot - approximately 65 miles - with ZERO events.
Observations (totally anecdotal):
1. All events happened between Denver/Salina KS and Salina to Denver. NONE occurred east of Salina on either leg of the trip (and those were 11 hour legs each way). Temps were anywhere from 64 to as high as 92. The events never happened on the warmer, sunnier climate days, but rather the cooler, cloudier days with little to no traffic.
2. Kids' tablet cellular signal loss on gaming/streaming seemed to coincide with the events, and both of our phones had very low LTE signals (Verizon). When an event happened late on the last part of the eastern KS trip, the kids would say they were kicked off their games.
3. We have premium connectivity annual subscription.
4. Three events we were actually able to TRIGGER. My wife decided to swipe down on the navigation screen to expand the destination list and SC charge time requirements, and just as she swiped up to collapse, an event occurred. We were on autosteer/navigation FSD setting at the time. Then I tried the same thing she did, and literally was able to recreate a phantom braking event when I swiped up to collapse. The third one happened when I set the car to just cruise control and then cautiously repeated the navigation expand/collapse process (warning the kids and my wife in the process!). Third event occurred - 75 mph to 61, then back to 75 slowly (another bug report recorded).
Summary of observations, theories of causes:
1. Doesn't matter if car is on navigate w/autosteer FSD or cruise control. Events occurred.
2. Turn off navigate w/autosteer subscription - we had no events for 65 miles. Probably coincidental since we were coming into the Denver metro area by this time.
3. Is there a link between bad cell signal in remote areas and phantom braking?? We had no events until we got into the western plains of KS and eastern blah of Colorado.
4. What was the deal with our being able to trigger three straight events by messing with the navigation screen? Wasn't able to recreate again later that same day.
5. We logged at least 20+ bug reports and plan on setting up service call with dates of the events, telling them to look at all data just before each bug report. Hopefully this will help their engineering team solve this issue.
FYI, this is our 2nd Tesla vehicle. We also own a '15 MS 70D with the upgraded MCU2, autopilot and free unlimited supercharging. Still can get 230 on a full charge out of the rated 240 range when new (!!). Took the car to / from Topeka 3 weeks prior (mid-April) to buying the MY, and absolutely loved the autopilot functionality. Rarely had to remind the car I was alert with my hand on the steering, zero events, running on SW version 2023.12.9 and a cool 83,000 miles. Was by far the most awesome experience aside from the longer SC stops (I can accept longer stops when it's free!) and some lane changing quirks where the car would change lanes and then have to come back to center after going a bit too far left/right in the lane. It was soooo relaxing to look around and let the car do its thing. Completely different experience with the new MYLR.
One random side note - after having free SC on the MS 70D Topeka trip (we never do SC long trips in that car), having to pay for SC sucks, and is way more $$ than I thought. Last year we took our '21 Suburban to KY and spent $406 in gas round trip at $3.25 / gallon and a crappy 17 - 19 mpg. Total spend on MYLR supercharging on the same route? $301. Not much of a savings for adding more time on the trip...but hey, we're doing our part for the earth, right?
Sorry for the long post, but I'm hoping it helps others with their phantom braking issues! And maybe a lurking Tesla engineer will take note!
