How will multiplexed wiring age?

Simon Canfer · Post by **Simon Canfer** » 14 Mar 2004, 21:34

Given my experience of ZX door wiring connectors to give intermittent contact at best, I was wondering how the multiplexed wiring, fitted to later cars, copes as it gets older. A Xsara brochure I have shows the same connectors on the door pillars as the ZX.
On one hand, maybe the digital nature of the signals makes them less prone to poor connectors; or maybe poor contacts could confuse the system and open the windows/unlock the doors when you least expect...
Any experience of problems yet?
Simon Canfer

AndersDK · Post by **AndersDK** » 14 Mar 2004, 22:00

Hi Simon -
The multiplexing wiring on newer cars is not 100% multiplexed. Some of the simple functions requiring only a small signal current (no motor drive power) are still the old system with single wire pr function.
As you know the rear lights clusters takes quite a few wires carrying lamp power on old systems - typically a multiplexed wiring system on newer cars.
A failing wire - is still a failing wire - no matter standard function or multiplex system.
In multiplexed systems - you would have a whole range of related functions missing/failing on a wire fault - like rear cluster lights all failing. Probably the body computer (multiplex ECU) would notify you with an error message on the system display - that would be a sensible implementation on multiplex systems.
I don't consider multiplex wiring faults a complex problem - it's more a matter of thinking new ways of possible malfunctions related to a different way things are implemented.
It's like the shift from carbed to injected engines - where you got rid of some wellknown old type problems - but then got a whole new range of problem types.

monkeyman · Post by **monkeyman** » 14 Mar 2004, 23:13

Good question!
Certain models of XM abroad have had multiplexing fitted for a while. Newer models of Citroens are now fitted with it, as described above, not every system on the vehicle has it. One of the advantages of multiplexing is there are less wires so less connectors and generally less weight, so should be more reliable. The problems at the moment are more software related. I.e downloads are regular occurances to correct running faults. Diagnostic tools are evolving to help the diagnosis of multiplexed problems, but the need to 'Think out of the Box' to fault find is a must! The need for a diagnostic tool in the future when the cars age, to rectify faults will be a must! Guess work will cost ££££££.

Paulxmski · Post by **Paulxmski** » 15 Mar 2004, 03:54

Yes,
we can probably look forward to glass-fibre lighting looms with single point of light source, and bluetooth wireless remote control of most functions door opening locking, engine management ,police control eg; where police wish to speak with driver car is stopped doors are locked on emergency security override - oh oh mobile phone rings car stops in overtaking lane of motorway - especially if it's done by CIT ah ah ha ha

wheeler · Post by **wheeler** » 17 Mar 2004, 00:08

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by Paulxmski

Yes,
we can probably look forward to glass-fibre lighting looms with single point of light source<hr height="1" noshade id="quote"></blockquote id="quote">
Citroen are already using glass fibre communication on some of their sat-nav systems. [8D]

uhn113x · Post by **uhn113x** » 17 Mar 2004, 12:24

Look forward, maybe; buy the car, no

NiSk · Post by **NiSk** » 17 Mar 2004, 12:29

The idea of multiplexing is, naturally, to save costa for the manufacturer, even if they say that multiplexed systems are more reliable - I start getting a bit worried when I read information from one of my customers (Volvo Trucks) that "damaged multiplex wiring harnesses cannot be spliced, they ymust be completely replaced" - sounds like an expensive way of reducing costs! (for us owners)
//NiSk

wheeler · Post by **wheeler** » 18 Mar 2004, 00:19

there is no reason why a damaged 'multiplexed' wire cant be repaired,the wires of a multiplexed BUS are the same as any 'normal' wire on the car (just copper strands) they can be soldered etc if they become damaged/broken just like any other wire.

paranoid · Post by **paranoid** » 18 Mar 2004, 03:25

Lets get real people its Citroen were talking about, if its electrical its gonna be crap, if it carries anything that don't like water its gonna play up no matter how they dress it up.
Oh crikey just realised even the stuff that does like water (heater matrix, radiator) don't last long either,eh whats that dripping noise[:D]

monkeyman · Post by **monkeyman** » 18 Mar 2004, 03:59

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by paranoid

Lets get real people its Citroen were talking about, if its electrical its gonna be crap, if it carries anything that don't like water its gonna play up no matter how they dress it up.
Oh crikey just realised even the stuff that does like water (heater matrix, radiator) don't last long either,eh whats that dripping noise[:D]
<hr height="1" noshade id="quote"></blockquote id="quote">
Water leak? Must be a C3 Pluerial then.........Tee Hee!!!!!

esscargo · Post by **esscargo** » 01 Jul 2004, 08:18

im in australia and have a c3. Ive had it for a year now how do people think they will fare in the future.....?

uhn113x · Post by **uhn113x** » 01 Jul 2004, 13:01

<blockquote id="quote">quote:<hr height="1" noshade id="quote">im in australia and have a c3. Ive had it for a year now how do people think they will fare in the future.....?<hr height="1" noshade id="quote"></blockquote id="quote">
In nine years it will have, like all new cars, reached its eat-by date.....[:(][:(]