Hey guys, I'm a 2008 S40 owner. These days I encountered a trunk malfunction: it won't open anymore. Here I'm gonna share all I learned during these days.

So, if you encountered a trunk malfunction, please follow this checklist:

1. Is the trunk's button switch broken?
=If so, buy a button switch from Volvo retailers and replace it. Use screw drivers to undo the button column over the number plate and then replace it.
Here is exactly an example of solving this kind of trunk malfunction: =If not, proceed to the next item

2. Is the trunk's wiring hardness broken? Because S40's trunk wiring hardness would bends 180 degrees when you close the trunk, after a few years it would be broken.
=If so, consult your owner's manual and check your car if it's U.S. model or not. If it's U.S. model, it would be equipped with an emergency latch inside the trunk lid, you will be able to open the trunk temporarily by using this way, and then proceed to replace the wiring hardness.
Here is an example: =If not, proceed to the next item

3. Fuse malfunction caused the trunk won't open
=If so, Consult your owner's manual, and the fuse compartment is located in front of the right front seat. Follow the manual's guide to unlock the compartment and check the fuse for Trunk (which is No. 77 item in the compartment). If the fuse is blown, congratulations this is the easiest problem that can cause the trunk malfunction, you can buy a new fuse and replace the blown one.
While actually I don't think this would be possible. Because the circuits for trunk related electrics won't really be overloaded...
=If not, then you don't have any other item to turn to.

Why?

Because if your beloved S40 is not a U.S. model car, and your trunk cannot be opened, you will have no solutions to open it, not to mention to fix the malfunction. For many other cars, they all have manual ways to open the trunk if the electric one is broken. But here in Volvo S40, wow, the designer rely everything of trunk release switch on the electrics, and the electrics are so unreliable to withstand the metal fatigue!

If you are in the same situation as me, I would say, the mechanics in Volvo distributors have told me that in this case the only way out will be cutting and breaking the whole trunk lid and trunk lock from inside and then replace them all. I won't do something like that, it's pretty heartbreaking to do so. I will leave it there.

So, hope you guys won't encounter the same thing, and replace your trunk's wiring hardness on a regular basis before it finally went down. And also, try to install an emergency latch if your S40 is not U.S. model.

Thanks for reading and hope everything goes fine with you.