Reverse actually drove car forward!

[ekendahl]

My wife is having no luck with our new Tesla. Today she put it in Reverse, and when she pushed the accelerator, we went forward. I was sitting next to her and could confirm that the gauge cluster said “R,” and the rear camera was displayed. When she let go of the brake, we stood still. As soon as she touched the accelerator, we moved forward! Unfortunately, we ran out of space going forward, so we couldn’t test it more (and I didn’t think to grab my cell-phone and film it). She decided to put the car in Park and then in Reverse again. This time everything worked as expected.

Has this happened to anyone else?!?! Somewhat scary. I’m glad she was driving as I tend to push harder on the accelerator!

 

[murphyS90D]

Forward and reverse does not involve gear changes. The field rotation of the three phase motor is reversed. Whether that is done with solid state relays or actual relays I don't know. That should be reported to Tesla along with the date and time and time zone it happened in so they can pull the log and investigate.

 

[David.85D]

Please also remember the car will roll with gravity in either direction with no accelerator input once “hold” is released. I use this sometimes when parking on a steep driveway. Avoids changing “gear”...

 

[croman]

This was a bug with Raven drivetrain vehicles when stop mode first rolled out.

Never heard of it before or since that rollout.

 

[immolated]

Bug with stop mode providing negative feedback on small inclines

 

[maximizese]

I've had this happen to me as well on our 2013 S85 when the MCU1 got all glitchy and with a lower SOC%. I pulled into a SuC lot with 20% SOC and a frozen display. I put the car into reverse to back up into a stall and saw the "R" on the instrument display, but the rear camera didn't show up (display was frozen). The car lurked forward as I lightly pressed the accelerator. What was odd is that car seemed to be in some sort of limp-mode where the car wouldn't move at all without pressing the accelerator. I had "creep mode" on, was on a flat surface, and had to press the accelerator about 25-33% down to get moving.

Since it something was clearly wrong, I parked into a space in front of the SuC stall and did a two-wheel scroll button restart before proceeding. The car restarted and everything was back to normal. I mentioned this to the Service Center but nothing showed up in the log that would explain it. Sometimes I feel like I need a camera to document anomalies like these because I wouldn't believe it either unless I saw it. This only happened once in the 36K miles that we've driven the car.

 

[mongo]

Forward and reverse does not involve gear changes. The field rotation of the three phase motor is reversed. Whether that is done with solid state relays or actual relays I don't know. That should be reported to Tesla along with the date and time and time zone it happened in so they can pull the log and investigate.

No relays, this is not a fixed speed industrial motor setup. The motor's three phase inverter controls speed and direction.

 

[ekendahl]

I appreciate the answers and suggestions. I think it was an issue with "hold" and a minimal incline. Our front wheels were on gravel and rear wheels on pavement. I suspect hold did fine, but when my wife carefully pushed the accelerator, the hold mode released, but there were not enough electrons pushing "backward," so we rolled forward. I would consider it a bug. I know my wife was careful, but the SW shouldn't let the car move in the wrong direction when releasing the hold. We were not able to recreate it after switching back to Neutral, but I suspect that was because the incline was now even smaller, and it would have worked anyway. I'm not 100% sure.

 

[tranzndance]

I appreciate the answers and suggestions. I think it was an issue with "hold" and a minimal incline. Our front wheels were on gravel and rear wheels on pavement. I suspect hold did fine, but when my wife carefully pushed the accelerator, the hold mode released, but there were not enough electrons pushing "backward," so we rolled forward. I would consider it a bug. I know my wife was careful, but the SW shouldn't let the car move in the wrong direction when releasing the hold. We were not able to recreate it after switching back to Neutral, but I suspect that was because the incline was now even smaller, and it would have worked anyway. I'm not 100% sure.

It has happened to me and I've adapted to it. My husband's 3 works the way we would expect it to work: don't move in the opposite direction, even on an incline/decline. How new is your new car? If it's a Raven, there's a setting called Stopping Mode so the car would behave the way you would expect.