Hi,

I got the above msg on my keyless start S Max recently. Built up the courage and changed the battery thus morning, as well as programming it with the remote.

The problem is that it still displays the same "key battery low" msg.

I've gone into the messages setting but am unable to reset.

Any guidance would be appreciated.

Thanks

If you have reason to doubt the integrity of the replacement battery, or may have inadvertently replaced the old with the same (believe me, it happens!), try another one.

Re-programming isn't necessary if the battery is replaced and fob reassembled quickly.

Thanks,

Tried it, also tried with disconnecting battery as suggested by another member on the forum. Still the same.

Msg being displayed with both fobs.

Any suggestions?

Many thanks

check the voltage output of the battery to ensure its kicking out enough juice. You can get bad batches of batteries where the voltage is about half of whats reported, and that would generate this error,.

There is a known error with C-max whereby the battery warning doesn't reset.

It required a Body Control Module (BCM) reprogramming at a Main Dealer.

It sounds like the same issue with your car.