To avoid any problems with spiked or corrupted ECUs there are number of precautions to be taken. The SRS ECU (airbag), in particular, seems fairly prone to this and damage is often blamed on incorrect battery disconnection or jump starting procedures.
There are two options The first is the method i use for toping up the Battery with DI water. The second is Based on the official Peugeot Method . Peugeot refer to BSI (Body System Interface) Fiat BCM (Body control module)
If you have MES multiecuscan do a system scan to check for errors.

Physical access
Remove the cab carpet and there is the floor panel with coin turn fixings. A 50p piece is good tool, just half a turn on each.I find this easier to do with the door open, before touching the battery.

Method A
Fully charge a spare Battery.
Open drivers window.
Turn off ignition and remove the key and any diagnostic equipment or equipment being charged.
Open Bonnet and leave it up. prepare the jump start terminals. Using jump start cables Connect the battery to the jump start terminals.
The main battery can now be disconnected. And any items removed to allow access for Electrolyte checks.

Method B
Take all required tools into the cab.
If you have a cab radio that has a secure code have it to hand before you start.
If your alarm has special instruction for resetting either have the instructions or contact the supplier/installer.
If you have solar panels and a regulator such as the Votronic series that chrges the SB, or other facility that has a connection between the leisure and vehicle battery systems, I would recommend covering the panels and disconnecting them from the regulator.

Where the instructions state to wait 3 minutes after closing doors etc, I recommend 10 minutes if the ignition has been on within the previous 10 minutes, to allow the system to go into "sleep" mode.
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 (10) minute waiting period.

Note that this procedure on a Ducato or similar van with the battery inside the cabin, requires you to be inside the van with all the doors shut etc. as per the instructions before disconnecting or reconnecting the battery, so do the preparatory work such as removing the floor covering and battery tray cover first, then get inside the vehicle, shut all the doors etc. and after waiting the requisite time, disconnect the battery. The negative terminal often has a clip type clamp, rather than a bolt. which makes things easier.
cab-battery1.jpegCab-battery.jpgCab-BattteryNeg.jpgNote My Battery has extra fuses and gubbins for towing Electrics.
Now remove the terminal cover at the Positive end.
Remove these two screws and the red plastic retainer.
Now slacken the Positive clamp nut using a 10mm ring spanner and lift the lot clear.

Once the battery has been disconnected, wait at least 5 minutes before reconnecting it.
Again we can now access the electrolyte caps or remove the battery.

For removal
Check if vent pipe fitted and if so disconnect.
Shield the cable clamps to prevent them electrically contacting the battery or any metalwork whilst removing and refitting. Remove the old battery.
If you find it easier you can, of course, open the passenger door to swap the batteries once the cables have been removed, but
ensure you close all the doors again and you're back in the cab before refitting the power cables.
Clean the inside faces of the battery clamps.
Clean the terminal posts on the new battery.
Present the new battery.
Be sure to remove both transit plugs
Once the new battery is in, ensure the doors are still closed, refit the vent pipe and battery cables in reverse order (positive first,
negative last).
Wait at least 10 seconds then switch on the headlight switch before turning on the ignition.

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 BCU 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
6 Switch on ignition then start the vehicle and check system functions

If you have multiecuscan do a system scan to check for errors.
  • Like
Reactions: ben