Q70 key not working after battery replacement

[Normski]

Hi,

New member here from the UK. Proud owner of a 2015 Q70S 2.2d (diesel!) Sport Tech...

Loving the car but like any used car it comes with some things to sort out.

First off was that one of the key fobs wasn't working (intelligent key). I presumed the battery and replaced with the correct CR2025. However, the remote locking/boot opening is not working. The key is recognised inside the car if I hold it near the stop/start button so my thinking is that the car has lost the "pairing" with the key.

Have trawled the internets/YouTube etc and tried various things that folk have done on the likes of Q50/60 but alas nothing seems to work for me.

Thoughts?? All help really appreciated folks!!

Cheers, Noman

[VStar650CL]

The RFID system in the fobs is passive, it requires no electricity and will work even if the fob transmitters are both stone dead. It sounds like the transmitters in your bad fob are dead horses. Dealers all have a "quick test" tool to see if a fob is actively transmitting anything, and most will run it by the tool for free if you ask.

[Normski]

Ahh nuts. Thanks for the info @VStar650CL. Was dreading a visit to the dealer. Just called them and they want £180 per hour (min 1hr) for any investigation...

Will have to see if there's anyone else who can sort before I head to the main dealer.

[Llebcire]

I had this issue with the 2025 - there's information online that states the correct battery is the 2032. The voltage is the same, but the 2032 is slightly thicker and the 2025 doesn't consistently work.

Try the 2032 and see if that fixes the issue.

[Normski]

Thank you for all the suggestions/tips. Took it to an auto key specialist here in London. Turns out a few main things:
1. They reported these keys do not loose their coding.
2. When replacing the battery part of the key had been damaged. This was sorted relatively inexpensively and while I waited (around 20mins) for £35.
3. As reported by a few members, the key does have a habit of not making correct contact with the battery (poor design) so watch out.

Anyway, all now sorted! Thanks for your help guys. Now onto the other issues on the car. Infiniti pulled out of the UK a few years back and unfortunately didn't sell particularly well here. So finding a specialist is nigh on impossible

[VStar650CL]

They reported these keys do not loose their coding.

They're correct about that. The code in the fobs is stored in a permanent "WORM" (write-once read-many) memory, which is why the code is still accessible through RFID even if the transmitters are both stone dead. When key registration gets "lost", it's never the fob's fault. It's always because the re-writable EEPROM or flash memory in the BCM (or IMMU/ECM on earlier cars) got wiped or corrupted. That's usually fixable just by reregistering the fobs, causing the car to rewrite the corrupt memory.