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Speedo glitch and worrying wiring

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#1 keefie


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Posted 26 February 2018 - 12:00 AM



We've had this current Picasso since October. It's a 52 plate but only done 56k miles.


Last Sunday morning I drove a few miles and all was fine, but next time I drove it, that afternoon, the speedo had gone crazy. I've put a video of it here. I have also noticed that when parked if I blip the throttle the speedo reads non-zero and the "Parking Brake" warning comes up, as the car thinks it is moving. Often when driving and on overrun, the speedo reads 0, whereas when I have any throttle on at all it reads a flickering set of random numbers.


I had replaced several of the bulbs in the instrument cluster, so I took that out again and reseated both connectors. I also had a look behind the panel by the steering wheel. What is going on here? This does not look like a factory wiring job!


Pic 1

Pic 2

Pic 3

Pic 4


It looks like the thick red wire on the left has been removed from somewhere and the connector is taped up. Then a thick green wire has been spliced into either the yellow or orange wire and fed, via a fuse, into a relay, along with another thick red wire that comes out of the fusebox. A thin black wire comes from the relay, via another fuse, and disappears down the side behind the carpet.


I don;t think the dodgy wiring is connected to the speedo fault as it has been there since I got the car, so, I have two questions:


1) How to get the speedo working again - none of the posts I have found on here seem to have exactly these symptoms

2) What should I do about the wiring?


Thanks for your help



#2 ChrisGibbard


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Posted 26 February 2018 - 09:47 AM

Looks like some-one has had the speedo problem before. http://www.citroenpi...ault/?hl=speedo


The wiring looks to be professional  and not a "cowboy" job. Wonder if it had anything to do with a manufacturers re-call on this year and model. You could un-plug the relay to see what doesn't work, although I wouldn't recommend that. But the relay type should tell you what it does.


My best guess is that if you take out that fuse your heater fan will not work.

#3 keefie


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Posted 15 June 2018 - 12:47 PM

I ordered a new speed sensor. The next morning the speedo started working fine. It carried on working fine for 3 days, during which time the speed sensor arrived. Then it stopped working again and went back to showing seemingly random numbers


I have now replaced the sensor but the fault has not fixed.


I guess there may be a wiring fault, but how would it cause the throttle-related problems?



#4 thehytheman


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Posted 17 June 2018 - 09:22 AM

I had this on my mine it turned out to be the ABS sensor.

#5 keefie


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Posted 27 June 2018 - 01:23 AM

How did you trace it to the abs?