Prevent garage from closing on car liftgate

I have a rule in Rule Machine setup to close the garage door when the outside lux falls below a certain threshold (aka it’s dark outside) and it’s been open for more than 5 minutes. The problem is sometimes it takes longer than this to bring the groceries in and then the garage closes on the lift gate to our Ford Explorer. So for now i’m trying to avoid this by sending and speaking a message that the garage is closing 3 minutes before the garage actually closes. That way I have 3 minutes to intervene. I would like something more robust. What is everybody else doing? Right now my thought is to put a tilt sensor on the lift gate, but my concern is it coming and going from the z-wave network. Would this cause problems?

Yes, but you can build failsafe around that too. Why not using a switch (virtual or physical) to prevent the closure while you’re unloading the car? When you’re done, you turn that switch off and the 5 minutes auto closures will resume…

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Can you expand on this some? not sure how? Check for the latest event from the device or something?

Because that would require manual intervention. I’d like this to be automated.

Then maybe a motion sensor would be more helpful? As for safety, it greatly depends on your habits, I guess. I have my garage door opening/closing in conjunction with presence sensors, car sensors, st modes…

  1. Add a second hardwired ight beam sensor to the doorway that is always broken by the lift-gate.

  2. Add a Tilt Sensor to the lift-gate that reports when it is down, and add that as a rule condition.


That’s a great idea! I test mine regularly just because my door closes automatically and I may have kids running around when it happens.

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You could install a motion sensor and change your automation to “close garage door 5 minutes after last detected motion”.

Putting a sensor on the car which then goes in and out of range of the hub isn’t terrible, it’s basically the same as taking the batteries out of the sensor and putting them back in, but I wouldn’t risk any health and safety issues on it. It might fail to reconnect to the hub appropriately.

I don’t think SmartThings is reliable enough for this kind of safety issue anyway, though.

It can be difficult to add a second trip light sensor to the garage door itself because the door coming down will typically break the beam and then send the door back up. This is why door beams are usually so low to the floor.

You can try putting a trip beam a few inches in front of the door inside the garage so that the door itself doesn’t break the plane of the beams but the open lift-gate does. Some garage door controllers will let you add a second trip beam and some won’t. Of course then if you walk around behind the back of the car while the garage doors closed it might open again.

Another alternative is the old-fashioned “hang a tennis ball from a rope” so that the liftgate hits the tennis ball and then put a tilt sensor on the rope. That way when the car leaves, the sensor doesn’t.

But I still personally hate automatically closing garage doors that work off of anything other than a person viewing the door and ordering the close. The potential for injury is just too high. But that’s just me. Well, me and the manufacturers of automatic garage doors and underwriters laboratories. :wink:


You could always just brick it. When you don’t want the door to close, set a brick in front of one of the senses.

It’s not fancy and pretty, but it will never fail you.


I didn’t even think of an extra set of the safety beams mounted high! They are cheaper than I thought, too. I’ll have to find the owners manual for my opener and see about the feasibility of adding another set. Only problem with this route is the automation would never run. But I suppose once I go out and close the lift gate I could manually hit the button on the way in…but that’s so old school.

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I like the motion sensor idea… Sounds like that guy knows what he’s talking about… That our he’s a great BS’er…:sunglasses:

haha. We tend to get home, unload refrigerated items, feed the kids, put the kids to bed, and then eventually get the rest of the groceries. So the motion sensor wouldn’t help much since there may be an extended period without motion. Although i do need a motion sensor out there for when I’m working in the garage to keep the lights from turning off on me…

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You can probably wire them up in series.

You could use a contact sensor and wire to the light beam. So every time you cross it to get to the car it would reset the timer.

This is where HA gets cloudy. If you are remembering to manually trigger switches (or bricks) to prevent the door from closing, you might as well just close the garage door yourself when you are done.

The only truly automated way I see to do it is install a second set of eyes on your garage that break with the tail gate up. But then you have to set your ST rules to keep trying to close the door until it actually closes.


update! I got a Nyce tilt sensor on clearance at lowe’s for $9. After exchanging it at another location for the newer model that works with ST, I paired it and put it on the tailgate. I then updated all my rules that close the garage to only run if the tilt sensor is closed. We will see how this works with the car coming and going from the Zigbee mesh.


Just saw this, but I wanted to mention that You might consider changing it to not run if the sensor is open instead of running only while the sensor is closed. In engineering this would be called a “dead man rule.”

It’s all about addressing potential failures.

Say the sensor dies while it’s closed. The battery fails, it’s out of range, or it physically drops off the car and you leave it behind at the office.

The way SmartThings works is that it will continue to be reported as closed. So that means the rule could run even if the trunk door was physically open because the system thinks that the sensor was still closed. That means the garage door might come down on the car because your rule thought the trunk was closed.

Now let’s consider the opposite situation – – the sensor dies while it’s open. So the system continues to report it as open. Even if the trunk is closed. That one means the garage door will not automatically close because it still thinks the trunk door is open. Which isn’t good, but probably isn’t as bad as the garage door closing on the trunk mistakenly.

But it all depends on your purposes for having The rule. Maybe you want the dead man condition to be open, rather than closed.

It’s just worth thinking about both ways – – which consequence works better for you?


Thanks for the input JD! That is an interesting scenario to keep in mind. I guess the risk is the garage hitting the liftgate or the garage staying open all night. I’ll have to think on this one!

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