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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

Hi,

 

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

 

Keith



#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?



#6 keefie

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Posted 13 November 2018 - 12:23 PM

The speedo works now, turns out that there was an earth point on top of the gearbox and unscrewing that, cleaning it and doing it back up again fixed the problem.


  • Ozzie, gray and discv like this

#7 Ozzie

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Posted 14 November 2018 - 08:24 AM

thanks for the feedback , another one for the fault ' book '

 

time to start archiving all this useful info. judging by recent comments in General Discussion 

 

I find clipping the web page to Onenote the easiest way .