see here for some explanation under the heading: UNEXPLAINED ENGINE MALFUNCTIONS: Why do cars suddenly shut down and/or suffer strange electrical problems like the dashpanel lighting up or going out completely?
Vehicle Area Network (VANbus) is a bus used on some PSA group vehicles for body control - superseded in later models by:
Controller Area Network (CANbus) is a vehicle bus standard designed to allow microcontrollers and devices to communicate with each other within a vehicle without a host computer.
The "Vehicle Area Network" protocol was designed and used by collaboration between PSA (Peugeot-Citroen), Renault and BMW. Subsequently the European Union decided to take the US standard and make that a requirement (a good choice). PSA found a way to continue to use VAN by only having the engine ECU talk CAN to the main computer (that would be the BSI) and everything else talk VAN. Probably for cost reduction PSA then switched everything over to CAN. A nice example of EU legislation doing a good job of getting every car brand in line and achieving cost reductions because of that.
So - early 1007's (the vast majority) had the CAN-VAN protocol: the engine ECU is CAN and communicates with the CANbus protocol with the BSI and there is a CANbus that is connected to the OBD-II connector. That meant they complied with the EU standardization rules but the remainder of the car used VAN-protocol.
Later cars, probably for simplicity and sheer availability of other ECU's, Peugeot switched over to full CAN. The 307's were switched to full CAN in the beginning of 2005 so the 1007 probably just missed that window and was converted to full CAN in 2007
Yves adds: Note that Peugeot has a pretty conservative implementation of their CAN/VAN bus wiring. Almost all devices have their own pair of wires to a separate port to the BSI, with some minor exceptions. The advantage is that a single unit cannot disable the whole car. I have once seen a Renault disabled because the mirror was damaged, I'm not certain but I assume the mirror-wire probably disabled the car?
PP2000 is the dealers software - code readers will not go as deep into the electronics as PP2000. They can be bought on-line - then you will know almost as much as the Peugeot dealers.
However PP2000 is not that easy to set up as most will need to mount the software as a virtual machine on top of the existing operating system. I eventually bought an old laptop, installed XP3 and PP2000 runs beautifully in native XP3 - OR you could trailer it to a dealer . . . .
This is typical of ALL modern cars; not a failing of Peugeot or the 1007. The anti-theft immobilisers on modern cars have to be one ahead of and protect your car against sophisticated thieves these days.
I would prefer a simple switch on an elderly car myself and if I knew how to do it on the 1007, I would!