Trip Computer...

[belial]

First i would like to say hello to everyone as i'm new in your nice family.
I want to ask something about the trip computer. I am an owner of a 1400cc 75hp exclusive gasoline C3. I really don't understand what is the meaning of the trip computer for citroen. The only way i can use it is for counting the kilometres that i already have covered. :D My brother's car "Toyota corolla" can say how many kilometres are left for you to cover with the rest of the gas... What am i doing wrong?

[citron]

Hello!
First , sorry about my poor english!
I'm a new (one week) c3 owner, and in the fisrt days i have the same
problem. Then i talk whith local dealer and :

You have to click on the "o" symbol of the stick control of radio ( the one
that change the CD track on windscreen wiper comand)

Each clik changes the information on bord panel (how many kilometers, instant consuption , averages ...)

I hope this can help !

[mirimushu]

Hello,

I'm owning a C3 1.4i, 75 BHP petrol engine (TU3JP).
I noticed a somehow strange behavior of the trip computer:

When going down on an incline and doing 'engine break' (sorry, I don't know the exact term - I mean pressing no pedal so the velocity is kept constant by the engine resistance) it takes quite a long time (~10-12 seconds) for the trip computer to finally show the '0.0' instant consumption.

The instant consumption is slowly decreasing from its 'straight & level' value (for instance 6.5 l/100Km) to the 0.0 l/100 Km.

On other cars I drove the instant consumption is going to 0.0 far more quickly (max 2-3 seconds) during an engine break.

Are your C3s doing the same or do I have a problem with the ECU?

Thanks a lot!

P.S. Sorry for my poor English :lol:

[pork_pie]

A trip computer in all cars are 100% inaccurate and should be taken with a pinch of salt.

Drove a Xsara Hdi 110 down a hill once or twice and got 99.9 mpg shortly after setting off.

Sometimes if I set the computer to "instantaneous MPG" then I got 999.9mpg on many occasions.

The reading lack credibility like a political party mainfesto.

If you want accurate MPG use the old fashioned way.

A calculator and a pen to note down the mileage.

[hertsnminds]

The mpg or l/100km indicator is pretty much just an instant economy meter. It shows how much load the engine is under.

30 mph uphill in 3rd gear will give a different reading to 30 mph downhill in the same gear. If you are breaking and going downhill the engine is under zero load hence a reading of 0.0 l/100km or in the UK 999.9 mpg.

As for the Average readings these are not mentioned at all in the owners handbook and they average from the time they were last reset. To find out how to reset the averages see this website
[url="http://www.c3pluriel.org.uk/"]http://www.c3pluriel.org.uk/[/url]
and look in the TIPS section

All of the indications (fuel gauge, mpg or l/100km and the averages) seem to be very inacurate. The one thing that seems to be very acurate is the speed reading usually about 1 or 2 mph out compared to my GPS reading

Ian
Orange 03 Senso

[mirimushu]

OK, but the accuracy of the "instantaneous fuel consumption" is my second concern.

My first concern is the [i]time[/i] needed by the "instantaneous fuel consumption" to hit the 0.0 l/100Km (or 999.9 mpg). Why it needs about 10 seconds for this? The engine is under zero load since the moment I lift the foot from the accelerator pedal.

It looks to me that the "instantaneous fuel consumption" behave like an "average fuel consumption for the last 10 seconds".

Can you please check if your C3s are behaving the same?
If not, I may have a problem with the engine management.

During drive tests, I've checked the "instantaneous fuel consumption" on a Skoda Fabia and a Seat Cordoba and for these cars the "instantaneous fuel consumption" reaches 0.0 l/100 KM very quickly (about 2 seconds from the moment I lift the foot from the accelerator).

[pork_pie]

Hello

Dont worry.

10 seconds for a unit to give out a reading is perfectly acceptable.

Units on Toyotas and Hondas I have driven take an eternity to register such high figures.

Instantaneous does not hold any degree of credibility whatsoever.

A car does not do 999mpg or 0.0l/100km.

What about the fuel the car uses when it is at tickover speed? Can you travel 100km on no fuel?

The same degree of credibility applies to average consumption display.

Don't worry about the fuel computer.

It is a useless feature.

[stimc3]

The instantaneous readout on the C3 is calculated by the ECU & onboard computer. The same system is employed on the Picasso. Readouts or 999.99 are achieved due to the simple maths that are employed in the calculation. The update is only performed on the Picasso every 10 secs on early cars and 20 seconds on later cars.

On the HDi engine if you are going down hill and touch the brake pedal you swicth OFF the fuel supply.

The equation is Miles per gallon or distance traveled divided by fuel used. So you are still travelling so the distance is half a mile but the fuel used at that instant is zero.

If you divide anything by zero you get infinity. The readout is limited to 999.99 or 99.99 MPG so it displays this. As soon as you put your foot back on the pedal the readout rapidly reverts to lower numbers.

Whether the redaout is a waste of time or useful is upto the owner.

[pork_pie]

So that oil level gauge?

You believe that is accurate?

That is another bell and whistle that should have been omitted and the money that was used to research such a contraption should have been spent on better glue.

It may be up to the driver to judge whether its accurate or not but there is nothing wrong with lifting the bonnet up with a rag and finding out the oil level properly.

Nor is working out the MPG the good old conventional way with a pen and calculator and noting down the mileage.

Then again the odometer is not accurate either!

ARRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRGH.

Used to commute from York to Scotch Corner for 6 months Monday- Friday. Used three different cars. One was a Micra and the other was a Lexus.

Both registered a weekly commute of approximately 600 miles.

The other car - a Citroen C3 registered 630 miles.

So in 52 weeks one could accrue a shade under 1500miles.

ARRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRGH.

Technology is a drag.

Haven't some Pug 307 drivers had a problem with odometers that grossly overread?