KEYFOB BATTERY REPLACEMENT MG5 FL

[SUPERAL]

Following the low battery warning on my keyfob,I replaced the battery. However the key now refuses to function.
1. I have tried 3 x different batteries
2. The car does not recognise the key in the back up position.
3. The spare key still works fine.
4. I have tried the simultaneous lock/unlock process.

-Why does a seemingly simple process of changing a battery cause such a problem (I had similar issue with an MGEV 2years ago). What is my next step - go to a dealer?.

 

[Alb]

Perhaps the next step is to remove the battery and insert it the right way round!

 

[google1901]

There's a link for solution provided via another with similar experience:

View attachment 42850

 

[PeterHR2]

Did you do Step 9: 'Set the vehicle power mode to READY to resynchronize the key with the vehicle'?

 

[EvTek23]

There is a similar thread from @viki2410 titled:
Battery Key Change - Now won't work

The solution there was to disconnect the 12v battery

 

[SUPERAL]

Going it working. There was a disc on the negative side of the battery, which I peeled off and voila it worked. It was just too obvious to see! Thank you to respondents.

 

[Alb]

Was this the "nasty taste" disc?

 

[SUPERAL]

Was this the "nasty taste" disc?

Well, on the packet it does say "baby secure" so I guess it was. The packaging itself was almost adult proof.

 

[Alb]

Saved the baby and fooled the adult then
The last set of batteries I bought had the same but there were clear instructions on the pack about removal. It's a simple but very worthwhile safety feature.