While the previous software installations on on my Model 3 have worked very well, 2 weeks ago my car updated to build 2019.5.15 and my car's performance immediately changed for the worse. I have cleaned the camera lenses and windshield glass to make sure that is not the issue. Here are the symptoms:
When in either auto pilot or cruise control mode, the car will, occasionally, aggressively decelerate for no apparent reason. It has happened several times on straight sections of divided, well-marked highway with no vehicles or notable physical objects ahead. This is very dangerous as it could easily cause a rear-end collision. It frequently happens when changing lanes to an unencumbered lane; where you would expect the car to accelerate to the preset speed. Instead the car will rapidly decelerate - eventually resuming acceleration to the preset speed after a period of time. The danger is that cars behind me would anticipate no reason why I should suddenly decelerate. Using AP or cruise control has become nerve racking.
Automatic lane changing frequently does not work (nearly half the time). Given the manual turn signal, the car will approach the dashed line and will bounce off, rapidly retreating to the original lane. Once on a virtually empty stretch of perfectly straight and level highway, I gave the M3 more than half a mile to change lanes. The AP bounced off the dashed line about 10 times before I had to take manual control as other vehicles were approaching from behind. To them, I must have appeared to be an intoxicated driver and they proceeded to pass me carefully. For whatever reason, navigate on autopilot is able to signal and take exit lanes without difficulty.
When I approach stopped vehicles ahead, the adaptive cruise control leaves an inordinate amount of space between me and the car in front of me. If I touch the accelerator to close the space, the car sometimes will lurch and jerk, unless I disengage the cruise control altogether. This is not a serious issue.
When resuming from a stop, the start of the acceleration use to be very smooth, but it now jerks to a start. This is not a serious issue, but it was much nicer before. For the comfort of my passengers, I now start the acceleration manually and then shift back into cruise control.
Here's why this is a very significant problem. Sudden deceleration is a serious safety issue that I cannot remedy with driver oversight. If cruise control were to fail to slow in time, the driver can press the brakes manually. However, if the automatic system hits the brakes, there is nothing I can do to "un-hit" them except to disengage the system, but by that time, the car has already slowed dramatically and I am already in the midst of a dangerous situation. I'm looking forward to getting safely beyond software build 2019.5.15!
When in either auto pilot or cruise control mode, the car will, occasionally, aggressively decelerate for no apparent reason. It has happened several times on straight sections of divided, well-marked highway with no vehicles or notable physical objects ahead. This is very dangerous as it could easily cause a rear-end collision. It frequently happens when changing lanes to an unencumbered lane; where you would expect the car to accelerate to the preset speed. Instead the car will rapidly decelerate - eventually resuming acceleration to the preset speed after a period of time. The danger is that cars behind me would anticipate no reason why I should suddenly decelerate. Using AP or cruise control has become nerve racking.
Automatic lane changing frequently does not work (nearly half the time). Given the manual turn signal, the car will approach the dashed line and will bounce off, rapidly retreating to the original lane. Once on a virtually empty stretch of perfectly straight and level highway, I gave the M3 more than half a mile to change lanes. The AP bounced off the dashed line about 10 times before I had to take manual control as other vehicles were approaching from behind. To them, I must have appeared to be an intoxicated driver and they proceeded to pass me carefully. For whatever reason, navigate on autopilot is able to signal and take exit lanes without difficulty.
When I approach stopped vehicles ahead, the adaptive cruise control leaves an inordinate amount of space between me and the car in front of me. If I touch the accelerator to close the space, the car sometimes will lurch and jerk, unless I disengage the cruise control altogether. This is not a serious issue.
When resuming from a stop, the start of the acceleration use to be very smooth, but it now jerks to a start. This is not a serious issue, but it was much nicer before. For the comfort of my passengers, I now start the acceleration manually and then shift back into cruise control.
Here's why this is a very significant problem. Sudden deceleration is a serious safety issue that I cannot remedy with driver oversight. If cruise control were to fail to slow in time, the driver can press the brakes manually. However, if the automatic system hits the brakes, there is nothing I can do to "un-hit" them except to disengage the system, but by that time, the car has already slowed dramatically and I am already in the midst of a dangerous situation. I'm looking forward to getting safely beyond software build 2019.5.15!
