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jeffk · 11-20-2020, 07:58 AM

Here's a consideration. The tailgate is probably tied into the cars locking system. Most cars starting out locked, when unlocked with the FOB (it will NOT happen if you use the unlock buttons in the car), will, if no one opens a door in a period of time, relock themselves.

If they open the tailgate with the FOB, and do not open any other door, the locking system might decide that, in a minute, it should relock the car, INCLUDING closing the tailgate.

The issue about systems like this is that the programmer of the cars electronics must anticipate EVERY possible situation and build a proper response. In sophisticated programming environments, engineers grab various, predesigned software modules without fully understanding exactly HOW those modules work, in detail. An example in this case. Suppose a general locking software module for a CAR is extended by the engineer. He ADDS on the ability to deal with the tailgate, opening and closing it. But buried in the original module is the timeout relock feature. In the original CAR application, all that happens is the doors relock. No big deal. In the SUV, it ALSO closes the tailgate, a physical, possibly dangerous action. The software designer did not add this functionality when he added the tailgate capability. It was buried in the original code which he did not build and did not think about. If the previous designer of the CAR code was good, he documented this but minor features might not be documented. Then the new programmer needs to read the existing documentation. Maybe he does or doesn't and again, a minor function like this could be overlooked.

Confirmation tests for this would be:

1. When the problem does happen, is the SUV always locked when they open the tailgate with the FOB? A likely scenario is coming back from shopping and putting packages away.

2. With the car locked, unlock it with the FOB, open a door, and open the tailgate with the FOB. Does the automatic close ever happen?

The funny thing is, the software is trying to be "helpful" by a one touch, close all the doors and lock the car. It becomes a problem when the auto relock is triggered. Unintended consequences because the passenger doors can't be automatically closed. The tailgate is a similar, but not EXACTLY the same kind of door. The locking button on the FOB is a similar but not EXACTLY the same locking mechanism as the buttons in the car because only the FOB triggers the auto relock. The software needs to recognize and manage all these subtleties and the programmer needs to anticipate them all.

11-20-2020, 07:58 AM	#13
jeffk Senior Member Join Date: Feb 2004 Location: Center Harbor Posts: 1,130 Thanks: 201 Thanked 421 Times in 239 Posts	Human error? (Not the owner) Here's a consideration. The tailgate is probably tied into the cars locking system. Most cars starting out locked, when unlocked with the FOB (it will NOT happen if you use the unlock buttons in the car), will, if no one opens a door in a period of time, relock themselves. If they open the tailgate with the FOB, and do not open any other door, the locking system might decide that, in a minute, it should relock the car, INCLUDING closing the tailgate. The issue about systems like this is that the programmer of the cars electronics must anticipate EVERY possible situation and build a proper response. In sophisticated programming environments, engineers grab various, predesigned software modules without fully understanding exactly HOW those modules work, in detail. An example in this case. Suppose a general locking software module for a CAR is extended by the engineer. He ADDS on the ability to deal with the tailgate, opening and closing it. But buried in the original module is the timeout relock feature. In the original CAR application, all that happens is the doors relock. No big deal. In the SUV, it ALSO closes the tailgate, a physical, possibly dangerous action. The software designer did not add this functionality when he added the tailgate capability. It was buried in the original code which he did not build and did not think about. If the previous designer of the CAR code was good, he documented this but minor features might not be documented. Then the new programmer needs to read the existing documentation. Maybe he does or doesn't and again, a minor function like this could be overlooked. Confirmation tests for this would be: 1. When the problem does happen, is the SUV always locked when they open the tailgate with the FOB? A likely scenario is coming back from shopping and putting packages away. 2. With the car locked, unlock it with the FOB, open a door, and open the tailgate with the FOB. Does the automatic close ever happen? The funny thing is, the software is trying to be "helpful" by a one touch, close all the doors and lock the car. It becomes a problem when the auto relock is triggered. Unintended consequences because the passenger doors can't be automatically closed. The tailgate is a similar, but not EXACTLY the same kind of door. The locking button on the FOB is a similar but not EXACTLY the same locking mechanism as the buttons in the car because only the FOB triggers the auto relock. The software needs to recognize and manage all these subtleties and the programmer needs to anticipate them all.