xsara picasso dash mpg doesn't change - ECU?

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captainkephart
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xsara picasso dash mpg doesn't change - ECU?

Post by captainkephart »

Hi All,
I have a 2008 xsara picasso 1.6 DOHC petrol ... it's been a pain with engine fault light on and off and O2 sensor issues for over a year.
But now, a new fault. The dashboard display is working fine, but when I cycle through to the MPG display (not the real-time one), it's been showing 40.9mpg for weeks - it doesn't change. Does it sound like the ECU has given up calculating (or displaying) the computed value?

This is new ... normally mpg goes down if I do a motorway journey and gradually up again if if doing pottering about.
The reading was reset about 500 miles ago ...

I'm doing a full tank to full tank mileage check to see if it agrees with the dash reading.
Other than that the car runs fine - quite sporty.

Should I be worried?
Ciao, Captain K

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Paul-R
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Re: xsara picasso dash mpg doesn't change - ECU?

Post by Paul-R »

How many miles since you last reset the miles? The greater the number of miles the longer it takes for the MPG figure to change to match different driving conditions. Until, finally, at 6214 miles (that's 10,000 Km) the display freezes at whatever is showing.

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captainkephart
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Re: xsara picasso dash mpg doesn't change - ECU?

Post by captainkephart »

Hi Paul R, Thanks for asking. Was reset about 500 miles ago ...

PS: Nothing to do with this fault, but on a previous Piccie it was fun to go to the maximum miles in MPH mode, then change it to KMH - display very confused!

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Re: xsara picasso dash mpg doesn't change - ECU?

Post by Hell Razor5543 »

I prefer to drive them with the display set to live MPG. Then, when I go down long slopes using engine braking (and the right gear for the slope) I regularly see 999.9MPG!

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Paul-R
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Re: xsara picasso dash mpg doesn't change - ECU?

Post by Paul-R »

At 500 miles it'll take quite a bit of driving at a markedly different economy to have an effect. Unless you're keeping this mileage to show an average between fill-ups (which is what I do) then try resetting the mileage.

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captainkephart
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Re: xsara picasso dash mpg doesn't change - ECU?

Post by captainkephart »

Thanks Paul, that is, of course, the obvious thing to do!
For some reason I'd got locked into the idea that 40.9mpg was impossible for this car (previously it's always been in the upper 30s).
Ciao, Captain K