2016 V40 T2 R-Design - Both key fobs suddenly not working
 

Hi Folks,
New to the forum so hope this is formatted correctly.
Left the house this morning and tried to unlock the car - nothing.
Went and got spare key - nothing.
Changed Cr2430s in both fobs - still nothing.
Took off the manual lock trim on the passenger side door (why oh why is it on the passenger side?) and entered - alarm went crazy.
At first, neither fob would work in the slot to start the engine, but in panic may have forgotten to press clutch.
Eventually, main fob works in slot and engine starts. Folding wing mirrors are still not deployed though as they engage when the fob is used to unlock.

Questions:
Any idea what could have caused this? Car continues not to respond to either fob on any buttons (locks, lights, horn, boot etc.)
Is there a manual way to deploy folding wing mirrors?
Also managed to knock the rearview AND rearview stem off when getting from passenger seat to driver's seat. Any idea how to reattach the stem? I'll be a monkey's uncle if i can figure it out.

I am now having the same issue. Both my fobs do not work anymore with new batteries. The battery went flat on the one, so I used the other. Got a whole pack of replacement batteries.

When I replaced the spare's battery it stopped locking/unlocking the car. Still works in the ignition, but doesn't lock the car. Using the old battery does still work but I am getting a low battery warning.

I thought maybe I just have bad batteries, so I bought more from 5 different stores. All the same. No new battery works in the key fob, but the old battery is working.

Is it the wrong battery type/size? No, its the CR2430 (3V) which is the exact same one in there now.

This is just above me. I went through all 58 pages of the Volvo V40 2012 to 2017 forum and looked at all the fob related posts. Nothing helps. I can't imagine I need a new fob which most are recommending.

Now I went to other models and other forums and in the V50 they recommend updating the CEM at the dealer. Does that make sense?

Any solutions
 

Hi Both I have exactly the same problem, do you have a solution?

Thanks, Dan

Solution
 

just thought I would share what happened to me:

i changed both of the fob keys to no avail - it was the car batteries.

So the V40 has a main battery and then a smaller battery - the smaller battery charges off the main battery and I assume that was dead - because the main battery was almost dead (battery warning message).

I opened the car with the manual key and then started the car and kept in revving at around 3000 rpm for an hour.

This didn't solve the problem immediately but it did charge the main battery ( check with a meter) then the next day I did the same thing, then the third day it worked.

The smaller battery trickle feeds off the larger one so I think the consistent charge on the larger battery solved he problem.

Hope this helps!

Every thing works now - i will make sure to use the car at higher revs a a bit more and also vary that with the out door temp fluctuations