C4 Grand Picasso woes

[BMRuss]

Have a 2011 C4 Grand Picasso, been a lovely thing for a year, but now encountering a strange problem.

Flashed up on the dash that it needed a new battery, so installed one I did (was a PITA of a job!).

When I put the key in the ignition after putting the new battery in, it flashed up Electronic anti theft fault, car would just crank over but not start, full power to everything with the new battery, so I guess an immobiliser problem.

My key fob (my wife's car so I have the spare) wouldn't lock / unlock the car, but her key would, my key starts the car, but hers doesn't!

Then last night I went to unlock it with her key and nothing and nothing with mine, just the handbrake light would come on inside the car, then it would work again 20 minutes later.

Is this a case of going to a main dealer once I can get in it and start it and have the keys re-programmed or a new set of keys?

All from changing the battery, French electronics aaarrggghhhhhhhhhhhhhhh

[megamaniac]

Did you follow the procedure to reinitialise after changing the battery,or did you just try and start it straight away?

[BMRuss]

I just tried to start it straight away, didn't know I had to do anything else?

[BristolRich]

Does yours have the small fuse box mounted ontop of the battery? If so it might be worth checking them to make sure they are ok - There are instances where these have "popped" on swapping over to a new battery.

[BMRuss]

It has got the little fuse box on top yes, I've checked that and all seems to be fine.

I'm interested in this reinitialising business as I've not heard of that before so any further info would be gratefully appreciated

[megamaniac]

Put the driver's window down, lift the bonnet and ensure all equipment is switched off.
Ensure all doors are closed and remove key from the ignition.
Wait for 3 minutes, disconnect the vehicle battery and wait 15 seconds.
Reconnect the vehicle battery, wait a further 10 seconds (do not open doors.).
Switch on the side lights through the driver's window.
Switch on the ignition and check system's functionality.
Hold lock button on key down for 10 seconds.
Remove key open & close door test central locking system.
Start the engine and complete the system's check.

Copied from Citroen Owners Club

[BMRuss]

Thank you very much for the above, I shall try this later and report back.

In the meantime, my wife's key no longer remotely locks or unlocks the car, but now does start it, even with the 'electronic anti theft faulty' message, weird!

[BMRuss]

Tried the above but didn't work, but thanks for taking the time to post it.

Looks like a trip to Citroen is in order!