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2005 Grand Caravan with 168K. Rear liftgate will not close using either key fob or switch. On the way down it reverses about 1/4th of the way. It works fine manually. I replaced weak struts 3 years ago and it has worked fine until now.
Help Please.
Thanks
 

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Welcome to Allpar. It may be sensing interference on the way down, this will trip the reversing function for safety. Rusty or sticking hinges or lift struts? If those are OK, the binding may be in the power liftgate mechanism itself? Try to isolate the excessive friction if that is the issue.
The power liftgate module (PLM) can show switch states and store fault codes on a good scan tool (like the DRBIII or equivalent).
 

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The automatic full raising and lowering of windows in later Chrysler products (where you just have to press/pull the button a moment for the window to go all the way up/down) has a safety reversing feature, there is a Calibration Process in the owners manual to perform if the windows are reversing or stopping before they should. Don't know if there is the same for the power liftgate, but its worth looking in the O.M. to find out.

The windows and some power sliding doors and liftgates have the safety feature to auto reverse if they encounter resistance. The windows and sliding doors certainly seem to me, sense the current draw of the motor to determine if it encounters resistance. As the vehicle ages, wear and other factors can increase the resistance to raising/lowering/sliding the windows/doors. I'm sure you noticed old cars often have doors and windows that do NOT move as smoothly or easily as a new car.

So like IC said, these normal wear and tear things that resist the doors and windows opening are making the vehicle incorrectly sense that the door/window is encountering resistance and triggering the autoreverse, incorrectly thinking something got in the way and for safety the liftgate should be reversed as NOT to harm someone or damage something. If there is a "Calibration Process" that would account for the extra resistance in the liftgate and its hinges from wear and tear.

My '02 Grand Caravan had a power sliding door. When it would refuse to close, erroneously triggering the auto-reverse feature, several times. Often all I needed to get it working correctly was to clean and lubricate all the hinges and sliders as well as clean the seals. (I had young kids and made long trips, the result of spill snacks from kids made for very sticky sliding door seals that had a much higher resistance to opening/closing the door as it engaged the seals.

Just lubing the hinges may be all that is needed. I know the O.M. says to use white lithium grease to lubricate chassis hinges, but personally I have found penetrating oil, WD-40, does a much better job and makes far less of a mess. The penetrating oil often doesn't last as long, but the white lithium grease may NOT penetrate into the surfaces of a neglected and rusty hinge as well either. At least doing the WD-40 first, and more than once, to penetrate and break up corrosion, and then maybe go back in a month and use white lithium if you prefer.
 

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KOG
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Mobil 1 0W-20 makes probably the best hinge lube, thin enough to penetrate, but won't evaporate any time soon. Motorcycle chain lube can also work very well as it will penetrate and then thicken to stay in place. Silicone spray for seals/gaskets/latches.
 

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Mobil 1 0W-20 makes probably the best hinge lube, thin enough to penetrate, but won't evaporate any time soon. Motorcycle chain lube can also work very well as it will penetrate and then thicken to stay in place. Silicone spray for seals/gaskets/latches.
I've also seen those making their own custom brewed chain lube, state to use lighter weight Mobil1 synthetic oil as the base. So you're on to something there.

There are two different kinds of "Silicone" spray, there is rubber and vinyl surface conditioning spray (Armor All, etc) and there is Silicone lube spray. The silicone lube spray is pretty rare and its nasty stuff, made my skin crack when I accidentally oversprayed onto my fingers. You're talking about the Rubber/Vinyl Conditioning Spray Armor All or an equivalent from another brand, correct?

If the door seal (especially the sliding door seal on the mini-vans) is really sticky/gooey (those with kids know what I'm talking about), you really need to scrub it with a bucket of soapy water and a rag to get up all the goo, then do the same for the metal sealing surface on the door. Then when it dries apply the Armor All, that keeps it somewhat slick and non-sticking to the door.
 
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