Reboot the BSI

BSI = Built-in Systems Interface = Body Control Module

The BSI unit is basically a computer which handles a multitude of functions such as odometer value, central locking, lights and immobiliser. Some later BSI units are liable to corrupt their own software program if not "woken up" in a specific way after programming keys or battery disconnection.

 see here for further info on the fuses in the BSI 

Process of Rebooting the BSI in a Peugeot:
  1. Unplug any diagnostic tools from the vehicle.
  2. Make sure all the gadgets are switched off, the driver's window lowered and open the bonnet.
  3. Then close all the doors and take the key out of the ignition.
  4. Wait for 3 minutes, disconnect a battery terminal and wait for a further 15 seconds.
  5. Re-attach the battery terminals and wait a further 10 seconds keeping the doors closed.
  6. Turn the side lights on through the open driver's window.
  7. Switch on (don't start) the engine and check everything works.
  8. With the key in the ignition, press and hold down the lock button on the key for 10 seconds.  This should re-establish the link between the security system and the key.
  9. Check the central locking system by unlocking and locking the door consecutively.
  10. Start the engine and finish checking everything works.
Any other procedure could cause malfunctioning of different units which depend on BSI.

If your car won't start or the doors won't work even after a reset, try removing the link HS (or SH) in the BSI for 15 minutes and then replace it. This may also reset some of the preferences but should at least get you going!

The BSI and the ECU MUST be matched together; it is not possible to fit a second hand BSI to a Peugeot.

Repair is an alternative for replacement of the BSI
see the  BBA Reman information here