"Keyless No Ford key in car" and "Key battery low replace soon"

[Ann Jennings]

Hi, I've been having a problem with my Ford Focus 2013 (Diesel) recently.  Firstly I had messages telling me the ABS system was wrong and, following a diagnostic check,  a mobile mechanic changed the sensors on both rear wheels.  That seems to have done the trick.  However now I keep getting "Key battery low" etc.  I have changed the batteries on both fobs several times so that is not the case but I still get this message, together (now) "No Ford key in car".  That doesn't make sense as I'm in the car trying to start it.  To get the car to start (while I'm in it) I often have to lock and unlock it using the fob and sometimes I have to remotely open the boot lock (using the fob).  This is the only way I can get the car to start.  Once I do that, there's no problem.   I have been told via a Just Answer mechanic that it could be the immobiliser and that an auto locksmith could reprogram the fobs (?).  Has anyone else had this problem and if so how was it rectified?  Your help would be appreciated.  Thanks

[unofix]

The system just wants reset after the battery in the keyfob has been change. If you are completely sure that the battery is a 'good' one which measures at least 3.3V with a meter and fitted the right way up, then do the following:

Standing outside the car, use either keyfob. Press the buttons on the keyfob and Lock and Unlock the doors 3 times in 10 seconds.

[Ann Jennings]

On 8/20/2022 at 11:13 PM, unofix said:

The system just wants reset after the battery in the keyfob has been change. If you are completely sure that the battery is a 'good' one which measures at least 3.3V with a meter and fitted the right way up, then do the following:

Standing outside the car, use either keyfob. Press the buttons on the keyfob and Lock and Unlock the doors 3 times in 10 seconds.

 

[Ann Jennings]

 

Hi Unofix

Many thanks for that.  I think you may have saved me a lot of frustration (and money).  I am waiting for, yet again,  more batteries for the fobs (Duracell this time) and will fit them when I get them and carry out your instructions.   With the current batteries, on one of the fob at least, it seems to have worked.

I appreciate your advice.

 

Regards,

Ann

[StephenFord]

4 minutes ago, Ann Jennings said:

 

.. I am waiting for, yet again,  more batteries for the fobs (Duracell this time) and will fit them when I get them and carry out your instructions... 

 

Please don't waste time continuously replacing batteries, no matter what brand. You actually need to test them with a multimeter (or dedicated battery tester). You can get these online for £5 or thereabouts, and you can then test every battery you use for the rest of your life without having to simply guess if it's punching out the correct voltage. As already stated by @unofixyou should see 3.3v for a new fob battery, and once it dips below 3v, it'll give issues...