Apparently there's a routine to be followed when disconnecting and reconnecting. Don't know how important it is to follow in reality, I've swapped my cab
battery without following the above and nothing happened??From a fiat forum.
BSI (Body System Interface) Reboot Procedure (Ducato Body Control Module)
PROCEDURE FOR
BATTERY DISCONNECTION
Whenever a vehicle
battery has to be disconnected, switch off all equipment, interior lights etc, close the doors leaving the driver’s window open.
Switch off the ignition and remove the key and any diagnostic equipment.
Wait a full 3 minutes before disconnecting the
battery.
The BSi must be allowed to go to SLEEP i.e. into "active economy mode". Do not operate any equipment on the vehicle during this time. Remember, even opening the bonnet will wake the BSi on a vehicle fitted with alarm.
If the
battery is under the bonnet, open the bonnet first and leave it up.
ALWAYS disconnect any diagnostic equipment and do not operate any other vehicles in the vicinity during the 3 minute waiting period.
PROCEDURE FOR
BATTERY RECONNECTION
Unless otherwise instructed by Peugeot or Product Service, you must always carry out the following procedure, often referred to as a "soft re-boot", to minimize the possibility of the BSi corrupting its own software when reconnecting the vehicles
battery supply.
Ensure the procedure for
battery disconnection has been adhered to and importantly all BSi functions were switched off with the driver’s window left down.
1 Close all doors
2 Remove ignition key if left in ignition
3 Reconnect
battery. DO NOT open any doors
4 Wait 10 seconds
5 Switch on headlights through the driver’s window
6 Switch on ignition then start the vehicle and check system functions