Is the USB warning on page 165 a real concern?

[flamaest]

Can someone please confirm if this USB warning on page 165 is something to be concerned about in the BOLT? I assume it is the same system logic for the Volt/Spark.

page 165:

Disconnect the connected USB
storage device when the vehicle
is off. If the vehicle is turned on
while the USB storage device is
connected, the USB storage
device may be damaged or may
not operate normally.

I plan on keeping an iphone connected to USB, leaving it in the car. I wonder if USB draws power from the 12-volt when the car is off. I am hoping it does not.

 

[SeanNelson]

Can someone please confirm if this USB warning on page 165 is something to be concerned about in the BOLT?

I have no insider knowledge of this, but it really smells like CYA to me. I can't imagine any voltage spike that would damage a USB drive that wouldn't also cause problems for all the other electronic systems in the vehicle. I'm pretty sure the design wouldn't allow it.

 

[Pigwich]

Yeah there might be some back EMF voltage spikes when the starter disengages

I'm calling BS. There's so many electronic things in this car that would blow up if they had dirty power. I can't see how this would be possible.

On the other hand, MAYBE they're more worried about the file system getting corrupted if it's being accessed while you power up / down or that the OS in the head unit keeps stuff in a write cache that it doesn't flush often enough. This sounds like exactly the kind of thing that gets forgotten about.

 

[CGameProgrammer]

Ignore this. I use an ultra-low-profile USB flash drive for music and just keep it attached and haven't had any problems. Once in a while when I turn the car on it's unable to read the device; even the LED on the drive remains off, but unplugging it and plugging it back in fixes it. However this only happens rarely. I think it's a bug with the car's software.

 

[GetOffYourGas]

On the other hand, MAYBE they're more worried about the file system getting corrupted if it's being accessed while you power up / down or that the OS in the head unit keeps stuff in a write cache that it doesn't flush often enough. This sounds like exactly the kind of thing that gets forgotten about.

This is why you should always "eject" a USB stick from a PC before removing. However, this is only a problem with writing to the device, not reading. What would the Bolt be writing to a USB device?

 

[Schnort]

A lot of media players put some sort of database on the media. This database could hold all the extracted or downloaded metadata to make the player more responsive after the database is built.

 

[GetOffYourGas]

Ah, that makes sense.

I'm still foggy on why this would be a problem when you turn on the car. It seems to me it would be a bigger problem if you unplugged the USB device while the car was on.