FA+
Shop
A Flaw in the Firmware
12 years ago
General
Hey, have you got a Mark IV Volkswagen Golf? Know someone who does? Here's a fun little experiment you can try.
Unlock the car and open the driver's door to cancel the re-lock timeout. Close the door. Press the hatch release on the key fob, then lock the car with the key fob. Note that the doors lock, the corner lights flash but the horn does not beep.
Walk around and open the hatch. When you close the hatch, the horn will beep, signaling the alarm is now armed.
Now we're gonna do it again with one small difference.
Unlock the car and open the driver's door to cancel the re-lock timeout. Pull the hatch release switch on the inside of the driver's door, close the door and lock the car with the key fob. Note that the doors lock, the corner lights flash but the horn does not beep.
Walk around and open the hatch... SURPRISE!! Did you just wake up the whole neighborhood when the alarm went off? Fumble with the key fob for a minute before unlocking the car to disarm the alarm.
Strange, isn't it? Logic would dictate that if the comfort and control module knows the hatch can be opened, it shouldn't arm the alarm. And it doesn't... if you release the hatch with the key fob. But there's some sort of bug if you release the hatch with the switch on the inside of the door, even though it looks like the alarm isn't armed, it'll reach out and bite ya when you open the hatch.
And it's completely repeatable. In fact, I did it over the weekend to make sure I remembered it correctly before writing this up. I do have follow-ups to do though. Does the alarm LED flash by the door pin when the alarm is sneakily armed? And when the release times out (without the hatch being opened) does the system then beep-and-arm, as usual? I may check those out too and report back.
Of course this is a fun little bug that does nothing more than annoy and surprise. Now that cars are becoming more and more computer controlled, who knows what bugs are laying in wait for that perfect combination of events to release dire, dire consequences.
For those of you confused about "releasing" and "opening" the hatch, on MkIV and MkV Golfs, pressing the button or switch for the hatch allows it to be opened. You can hear the mechanism in the door shifting. However you still must pull the handle (or use the super-stealth logo on the MkVs) to open the hatch. If 30 seconds pass without the hatch being opened, the mechanism will reset.
I'm sort of curious if this same bug exists in Jettas or Passats, but I have a feeling when you press the trunk button, the trunk pops open right away. So you can't "release" the trunk and then arm the alarm. Anyone with a Jetta or Passat willing to speak up on this?
Unlock the car and open the driver's door to cancel the re-lock timeout. Close the door. Press the hatch release on the key fob, then lock the car with the key fob. Note that the doors lock, the corner lights flash but the horn does not beep.
Walk around and open the hatch. When you close the hatch, the horn will beep, signaling the alarm is now armed.
Now we're gonna do it again with one small difference.
Unlock the car and open the driver's door to cancel the re-lock timeout. Pull the hatch release switch on the inside of the driver's door, close the door and lock the car with the key fob. Note that the doors lock, the corner lights flash but the horn does not beep.
Walk around and open the hatch... SURPRISE!! Did you just wake up the whole neighborhood when the alarm went off? Fumble with the key fob for a minute before unlocking the car to disarm the alarm.
Strange, isn't it? Logic would dictate that if the comfort and control module knows the hatch can be opened, it shouldn't arm the alarm. And it doesn't... if you release the hatch with the key fob. But there's some sort of bug if you release the hatch with the switch on the inside of the door, even though it looks like the alarm isn't armed, it'll reach out and bite ya when you open the hatch.
And it's completely repeatable. In fact, I did it over the weekend to make sure I remembered it correctly before writing this up. I do have follow-ups to do though. Does the alarm LED flash by the door pin when the alarm is sneakily armed? And when the release times out (without the hatch being opened) does the system then beep-and-arm, as usual? I may check those out too and report back.
Of course this is a fun little bug that does nothing more than annoy and surprise. Now that cars are becoming more and more computer controlled, who knows what bugs are laying in wait for that perfect combination of events to release dire, dire consequences.
For those of you confused about "releasing" and "opening" the hatch, on MkIV and MkV Golfs, pressing the button or switch for the hatch allows it to be opened. You can hear the mechanism in the door shifting. However you still must pull the handle (or use the super-stealth logo on the MkVs) to open the hatch. If 30 seconds pass without the hatch being opened, the mechanism will reset.
I'm sort of curious if this same bug exists in Jettas or Passats, but I have a feeling when you press the trunk button, the trunk pops open right away. So you can't "release" the trunk and then arm the alarm. Anyone with a Jetta or Passat willing to speak up on this?
What was that about the 'super stealthy' logo?
You press the top-half of that bright, shiny VW logo. The logo tilts along the horizontal axis and that pops open the hatch. The first time I found it, I scared myself. I was idly pushing at the logo and suddenly it tilted inward! Was not expecting that. ^_^
Random trunk-related story: I once got bitten by a Caddy, when I worked for Avis. They had the 'mostly close then electrically pull shut' trunks, and I closed it, noticed it hadn't closed all the way, put my hand under the edge to reopen to reclose JUST as the motor started pulling it shut...
Fun part, is doing this after I get home from work. And I work 2nd shift.
I've found three accounts, though in all three there is the possibility the driver was simply faking it as a compensation scam. Here's one:
http://www.independent.co.uk/life-s.....h-8494031.html
It did occur to me once that since the Prius does regenerative braking before friction braking, some part of that brake pedal has to be electronic. If that's a mechanical dead-zone before it actuates the master cylinder or if it's all electronic, I don't know. But if it's all electronic... I worry...