rear hatch fails to lock/unlock

[fortow]

This is just another one of the unnecessary bugbears of this over-electronically-complicated vehicle. The engineers were just too anxious to play with the technology. A simple and proven mechanical design would have sufficed. Instead they got fancy and created problems. My lift gate has also refused to lock several times. Leaving it for awhile seems to correct the problem However, if I was at a mall and had to lock the car then there would be a serious issue. If the lift gate won't lock, then the doors won't lock either.

[Terry Stibal]

Unfortunately, these electric motor operated lift gate latching mechanisms are becoming more and more common, not just on smart vehicles. The price of progress, not just over complicated smart technology.

The last three vehicle that I bought had either a remote operated latch (Toyoto Previa and Sienna) or a switch operated tailgate (on the Scion [i]xB) where a touch to a rubber covered button activates the motor that does the magic. All of them worked just fine for the life of the vehicle.

[fortow]

Originally Posted by Terry Stibal

... All of them worked just fine for the life of the vehicle.

Right - what I should have added is that the R&D and as delivered componentry weren't quite up to world standards. There's no reason why these foibles should be continuing. If smart recognizes that there are serious weaknesses like this they should be issuing service recalls to correct the problems, or at the very least inform dealerships about these common problems through technical bulletins and have the parts replaced when owners have their cars serviced whether the car has shown the problem or not. This lock issue will happen to every car eventually. Maybe they already do this - I don't know.

[HerrZ]

My hatch failed to lock one cold and snowy day in March. It acted like it was frozen with ice inside the mechanism. When i got to the dealer, it was still below freezing, but the latch worked. The dealer could not replicate the issue (of course). They tested the circut and found nothing wrong, but installed a new latch mechanism anyways. Kudos to Fairfield CT smart.

[fortow]

Well, it happened again today.

This is not certain but it may have something to do with how the lower gate is shut. I have a tool bag in the rear compartment that sometimes interferes with shutting the gate. On two occasions now when forcing the lower gate shut with this bag interfering, the window hatch refused to lock. The lower gate did shut but may not have shut to the complete satisfaction of smart.

I pushed the locking pawl in but it would not stay in. After opening and shutting the lower gate several times, and locking and unlocking the car, it did decide to work.
In my case, it is quite certain that there is something else occurring other than with the lock itself.

There's no point in changing the lock or switch since it will surely happen again.
The cause/effect relationship here may not be well understood. Even though it occasionally refuses to work, it will eventually lock with either fiddling with the lower gate or just leaving it for a given amount of time.

More investigation is required. What a fun, interesting little car. It has the personality of a devilish little child.