Tailgate close button not working

[DaiRees72]

My next move would be to check the wiring at the hinge point. I've found broken wires inside those rubber boots on many vehicles in the past, repeated flexing causes them to fail.

[pierremcalpine]

Originally Posted by DaiRees72

My next move would be to check the wiring at the hinge point. I've found broken wires inside those rubber boots on many vehicles in the past, repeated flexing causes them to fail.

Thanks, good tip. I have had to do this with my friend's 2004 V70 but I would have thought that they improved the design for the 2008+...maybe I was wrong!!! When I pulled his out of the side panel all but one wire were totally severed. I think they changed the location of the wiring on mine - they come up through the top centre of the tailgate...I suppose it's still possible for a wire in there to be frayed though...

[pierremcalpine]

Well, the verdict is that a new POT module (power operated tailgate module) is required (according to dealership). Part #31217840. The cost of this online is $400USD. Ouch. My local dealership wants $800USD for parts and labour. Ouch x2. That's a steep price to pay so that a close trunk button works.

So, having been a faithful owner of a V40 for over a decade and having replaced a $2 relay on the CEM instead of spending whatever crazy amount of money a new CEM costs just to get the headlight working, my curiosity is now really peaked.

Obviously there's no way the entire CEM is fried, just one little component. Now I just have to figure out which one it is and determine whether the component itself is removable/replaceable. Unfortunately, this is not my forte. Any one have any ideas? I plan to get access to the POT once the weather warms up.

Does VIDA have detailed electrical schematics of the POT itself, I wonder? I've got VIDA but haven't really explored what info is available for the electrics.

[DaiRees72]

Hmmm, my inherent distrust of dealerships would lead me to check all connections and wires for continuity before spending anywhere near that kind of money. Then I'd get the part number of this POT module and start searching the interwebs for a 2nd hand one out of a scrapper.

This just sounds like the time a friend had a £1000 lcd instrument panel replaced on his Mondeo (under warranty, luckily) when the fault was eventually traced back to a £14 sensor.

[pierremcalpine]

Well the saga continues. The tailgate continued to behave weirdly so I decided that I was going to throw a new POT module in. Before I did that, I bought all the relays for the old POT and replaced them all just for kicks to see if the relays were faulty. No dice. In fact, once I did that, not only would the button not close the tailgate but I no longer had the power open available to me either...nice.

Today, I got the dealership to load the software for the new POT. I'm back to square 1: I'm now able to open the tailgate without issue but it still won't close!!!

The mechanic has suggested that replacing the pinch sensors is the next logical step. $80USD each. This does make some sense as one of the pinch sensors has been partially detached for the last 9 months. It became detached at the top and then just peeled downwards off the body over the course of the last year.

Buuuuut, now I'm wondering...is there a way to short the pinch sensor so that the POT is fooled into thinking there is no issue...I have very limited patience with the electronics side but am wondering if anyone one has a good idea on how I could short one or both sides out to see if that allows me to close tailgate successfully with the hatch button.

Any ideas?

[volvo for ever]

if tailgate opens electrically ok and wont shut with but 1st thing to check is when tg open is tg light working this is good tip you will probally find its lost its earth its the same earth for switch that closes tg ,,it gets its earth from tail gate lock there is 2 earths in there pin 3 and 4 pin 4 gives light and switch the earth ,,

hope this helps

if you remove tg panel on the pot green plug think it 2nd black wire thats earth piece a bit of wire in and then straight to swith then test it that it will close this will prove its lost its earth

[pierremcalpine]

Originally Posted by volvo for ever

if tailgate opens electrically ok and wont shut with but 1st thing to check is when tg open is tg light working this is good tip you will probally find its lost its earth its the same earth for switch that closes tg ,,it gets its earth from tail gate lock there is 2 earths in there pin 3 and 4 pin 4 gives light and switch the earth ,,

hope this helps

if you remove tg panel on the pot green plug think it 2nd black wire thats earth piece a bit of wire in and then straight to swith then test it that it will close this will prove its lost its earth

Hmmm, thanks - interesting. Are you referring to the "dome light" by any chance? I've been having some issues with it as well as it isn't always working. Coincidentally I replaced the dome bulb yesterday (with a LED) and all of a sudden the tailgate started to close properly again...I'm convinced these two things are related!

[volvo for ever]

i believe the catch is faulty my friend not giving out earth if it happens again see if boot light works when sytem is down update if fault reoccurs

regards

[pierremcalpine]

Thank you for the reply. Is the "catch" the same as what volvo would refer to as a lock motor or motor actuator? That was their suggestion too as to what to do next. Not a cheap piece though at $300usd.

[pierremcalpine]

Originally Posted by volvo for ever

if tailgate opens electrically ok and wont shut with but 1st thing to check is when tg open is tg light working this is good tip you will probally find its lost its earth its the same earth for switch that closes tg ,,it gets its earth from tail gate lock there is 2 earths in there pin 3 and 4 pin 4 gives light and switch the earth ,,

hope this helps

if you remove tg panel on the pot green plug think it 2nd black wire thats earth piece a bit of wire in and then straight to swith then test it that it will close this will prove its lost its earth

That totally makes sense - thank you for the tip on how to bypass earth. Is there a Reason why I could not keep that solution as a perm fix?