From my orignal post:
Peugeot Vehicle computer explanation
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Like many homes Cbus is a system that links, wiring, sound and communication systems in one. The Cbus system allows for only two wires + and - in the cars with the data or computer codes travelling on top of the copper wires, thus saving the excessive wires from conventional systems and saving costs to the owner and the manufacturer. The system can be upgraded and fixed and best of all there are no moving parts apart from the engine.
Also in many of the forums, owners adding a new stereo or stacker or even alarm is a painful issue, peugeot did not create this system to make life difficult for the owners they did however make it easy to install an approved system by a quick software download. The multiplex computer operates where all switches /stereo doors windows come in to the unit as an input and out as an output, keep that in mind next time you try to install something.
Take a stereo for example all power/speakers and switches are received by the computer and send out the corresponding command eg speakers for sound. If you take away the peugoet stereo you cut the link to the computer and the speakers thus no sound, the only way to fix that is to join to the speaker wires seperately, the future problems are the mulitplex system will receive a reverse current and eventually may cause issues-may cause.
Believe me peugeot should be commended for this system, as I have created modules that control lights, indicators, alarm, locking, wipers, etc and believe me it was a headache 1 for mounting and wiring and two for fault finding.
The bottom line is that you
-cannot turn economy mode off
-cannot replace your indicators with leds unless they contain resistors
-cannot just plug a new stereo in without a software upgrade
-cannot install a stacker without a software upgrade
-cannot install a peugeot genuine alarm without a software download
You Can however
-install an aftermarket alarm - only if it is a mutliplex upgrade system
-install an aftermarket stereo if you don't want to use the peugeot controls
but you may need to change the software if it is a post 2004 307-407-607 etc
Computer fault messages:
-Economy mode- battery saving will shut down all consumption items to allow you to at least start the car
-Oil low check oil, uneven road surface or your oil may be low
-STOP- engine failure call a tow truck!!
This is a reference only -please add for info as desired.
Don't cut the wires just make sure the connectors are not cheap chinese ones, the sound will be worse with those connectors, go for reputable audio conversion brands. Make sure their is only two wires on each speaker..