Vy2 key fob not working

[natsroy]

Hey guys I have done a search but still not sure what to. My fob went from working fine to not locking or unlocking at all the car still runs and drives fine so I assume the slip ring is still getting a signal, I have tried changing the battery but still no change. Any ideas?

 

[tml678]

From memory, the VY key is the same as VR-VX..

Have the small black buttons inside collapsed perhaps? If you open it up and press them, do they ‘click’?

If you sit in the car and manually lock or unlock the doors, will the alternate button work on the fob, ie if you lock the door with your hand, will the unlock button on the fob work (and vice versa)? This will isolate any one faulty button.

If it doesn’t work at all, it might be an issue with the key itself. Can’t see it being the relevant module in the car (BCM I believe) if it still disengages the anti theft function and starts the car when inserted into the ignition

 

[Fu Manchu]

The fault will be the battery.
The slip ring will power the key when low voltage occurs. This means doors won’t unlock etc (this is operated through a different circuit and received via the sun sensor in the middle of the dash.) but the car starts and functions as designed once the key is in contact with the ring.
Changing the battery involves soldering a new battery in (of a particular type which has welded pins on it) into the circuit board.

I’d just get a new genuine key from Mister Minute. Sorted.

Avoid the aftermarket keys. I have a bag of failed ones from over the years.

 

[tml678]

The fault will be the battery....Changing the battery involves soldering a new battery

OP has already changed the battery Fu..

I have tried changing the battery but still no change. Any ideas?

received via the sun sensor in the middle of the dash.

Assuming OP has a Berlina or Calais..

 

[Fu Manchu]

I understand, but changed it using what method? The problem may be the sensor in the top of the dash, though unlikely. There would also be problems with the AC and with headlights if that was buggered.

You can fk up the battery quite easily.

 

[tml678]

I understand, but changed it using what method?

Agreed, but the key still starts the car. If the battery wasn’t installed correctly, the key wouldn’t work at all

 

[Fu Manchu]

BCM door relays could be buggered.

 

[Fu Manchu]

What is the voltage on the old battery?

 

[Fu Manchu]

Voltage on the new battery?
Multimeter earthed to the key and positive to the pin.

 

[tml678]

I’d just get a new genuine key from Mister Minute. Sorted

I’d agree with this too OP, especially if the key is original

What is the voltage on the old battery?

would be in the tip by now..