Odd FSD fail

[sleepydoc]

I started a trip using FSD 69.2.4 yesterday and within 2 blocks it gave me a panic disengagement with the red steering wheel as it approached a stop sign. I disengaged, made the turn, then reengaged a bit later and noticed it failed to make a turn, even though the route was correct on the map. Then I noticed something odd - the red arrow on the map representing the car was pointing the wrong direction. When I looked at the compass, it was also wrong (but matched the arrow,) saying I was heading north rather than southeast. As I drove the arrow on the map would inch northward, moving off the road, and the map would continually recalibrate, then every 15 seconds or so the arrow would jump back to the road and the process would start again.

What was interesting was that it appears the nav system intermittently checks the GPS data for location and between those checks it seems to use the direction and speed data to interpolate the car's position. There doesn't seem to be any mechanism for it to reconcile a discrepancy between the GPS data and the compass/vehicle speed data. It also appears that there was a software bug affecting the compass data.

I'm guessing that's what caused the system to panic - there was a significant discordance between the FSD camera input, the GPS data and the compass data. I've never actually seen this before or seen it mentioned here but I wonder if this has happened other times when I haven't noticed. If the compass is subject to software bugs, it could easily cause spotty issues.

 

[KLam]

GPS rely on satellites signals for positioning. Sometimes it fails. I know this because I use GPS when playing golf. Sometimes the GPS just failed to lock on to give my position for whatever the reasons.