Citroen Xsara Central Locking

After a flat car battery, my Citroen Xsara (2003) remote locking fob (PLIP) stopped working.

After searching on the internet, I found that if you hold the Lock button down for more than 10 seconds whilst the key is in the ignition, it will marry back up to the car and everything will be fine. Well, it didn’t work!

I went into Dutton Forsharw’s in Preston, and was told that sometimes after a flat battery, the car ‘forgets that it has central locking’ - that didn’t make sense to me as it was the fob that was messing me about. The guy took the fob away and came back telling me that it could not be married up to any car, and I’d need a new fob at £140.

I’ve been using the key in the lock for the past week, and today, the car central locking stopped working completely. This is a real problem as it is now impossible to lock the boot!

I found a sequence on the Citroen Owner’s Club Website, thanks to Andy which tells you to:

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

I went through this sequence, and lo-and-behold, the central locking works again. The fob, however, even with a new battery still doesn’t work.

All I can think is that the car computer holds many parameters in RAM, and if the battery voltage gets low, this RAM gets corrupted. When you re-charge the battery, the computer doesn’t reset, and it is possibly this faultily operating computer that talked to my key fob in swaheli and trashed it.

Unplugging and re-connecting the battery enabled the computer to start working correctly.

I’d suggest that whenever a battery in a Citroen gets very low, the computer should be re-set by disconnecting and re-connecting it before doing anything else.

If I’d followed the charger instructions properly, I’d have disconnected the battery to charge it anyway!

Fixing the Remote

I took the car into Dutton Forshaws in Preston, and they told me that the remote was broken, and I’d have to buy a new one. This seemed strange - how could letting a car battery go flat break the remote?

I was only passing through Preston, so took my car into my local Citroen Dealership in Letchworth and asked them. They told me that there was absolutely nothing wrong with the remote, and took the car to the service garage to take a quick look. The guy came back about 10 minutes later with a puzzled look on his face, and suggested that it needed to be brought in for a full service, so I booked it in.

On driving out of the garage, I noticed that the indicators didn’t work - neither did the wipers, nor the headlights … I took it straight back, and the puzzled guy took the car back. 5 minutes later, he cam to me and told me that the lights, and wipers were now working fine … and by the way, so was the remote!!

He had done a full reset of the computer - this is something quite fundamental, and does not appear to happen normally when the battery is removed. I have no idea what this reset is called, but suspect that they are reluctant to do it as the car also looses some other important parameters (perhaps learned engine tuning parameters?).

Anyway, the car is now working fine!

My lessons learned -

1. Follow the instructions properly on how to reset your car after a flat battery.
2. If the daft car repair man tells you something is broken - something that was not involved in the original problem, go get a second opinion.
3. Make sure absolutely everything is reset in the computer, and you may get your keys to work.
4. Use the Letchworth Citroen Repair Centre - they are extremely helpful and considerate.