Fuel Light And Chime.

[sonic113]

Ok guys to keep this short and to the point a few weeks back I did a Rom update with elm config to enable eco mode and dds and all works fine.

Thing is since the update I notice my low fuel light comes on now at 62 miles to Empty in stead of the usual 50 miles to empty. It does not chime at 50 at all. Has any one else noticed this or know why this is and if it can be reset back to the standard light and chime at 50 ,25,12 miles to empty?

Is there a setting or something within elm to alter this maybe?

Any input would be greatful. I'm just trying to get to the bottom of why this has changed after the update. All else is running 100%.

[JW1982]

On the newer firmware versions of the MK2.5 instrument cluster the fuel warning message and warning light are not displayed on fixed values anymore but adaptive. The remaining distance on which the low fuel warning light and message are displayed are calculated by some variables like for example current fuel consumption, average fuel consumption, driving style and speed.

This is a self learning system which becomes more and more accurate over time.

[sonic113]

On the newer firmware versions of the MK2.5 instrument cluster the fuel warning message and warning light are not displayed on fixed values anymore but adaptive. The remaining distance on which the low fuel warning light and message are displayed are calculated by some variables like for example current fuel consumption, average fuel consumption, driving style and speed.

This is a self learning system which becomes more and more accurate over time.

Thanks for reply . So through time this should settle itself down ?

Also does this mean that the amount of miles to empty can vary before the light/chime comes on depending on other variables (driving speed, driving style) and it won't be fixed anymore like the older version at 50,25 ect?

[TomsFocus]

How can it be variable? Don't understand the point of it myself? Is it now based on the 'time' you'll use the remaining fuel rather than the number of miles you'll cover?

Mines on the solid 50 and 25 anyway, just intrigued. :)

[sonic113]

How can it be variable? Don't understand the point of it myself? Is it now based on the 'time' you'll use the remaining fuel rather than the number of miles you'll cover?

Mines on the solid 50 and 25 anyway, just intrigued. :)

not sure myself fella. I always thought it would be solid on the 50,25 ect as before the update. Im intrigued myself to find out whys it not doing as before and coming on at 62 miles left now.

[JW1982]

How can it be variable? Don't understand the point of it myself? Is it now based on the 'time' you'll use the remaining fuel rather than the number of miles you'll cover?

Mines on the solid 50 and 25 anyway, just intrigued. :)

The value at which the fuel warning light illuminates depends mostly on the current fuel consumption related to the average fuel comsumption. If the system a higher fuel consumtion than the average fuel consumption the fuel warning light will be illuminated a bit earlier.

The original MK2 instrument cluster of my previous Focus MK2 used fixed values for the fuel warning light. After I installed a 2010 MK2.5 instrument cluster I noticed the adaptive system. My current Focus MK3 does also have this adaptive system. Usually my fuel warning light is illuminated at about 90 to 100 Kilometers remaining.

I also discovered that that the memory of the adaptive system will not be erased by reprogramming the instrument cluster. I installed a MK2.5 instrument cluster to my MK2 which came from a scrap car with the same type of engine and a very low mileage. This worked without any problems and the adaptive system adapted itself within a few gas fillings.

Other people who installed a MK2.5 instrument cluster from a different engine type and with a much higher mileage do often have the problem that the adaptive fuel warning light does not function correctly. In some situations the fuel warning light is even illuminated at about 200 Kilometers remaining. The higher the mileage of the instrument cluster the longer it takes to adapt to the new situation.

[TomsFocus]

The value at which the fuel warning light illuminates depends mostly on the current fuel consumption related to the average fuel comsumption. If the system a higher fuel consumtion than the average fuel consumption the fuel warning light will be illuminated a bit earlier.

Thanks, that makes sense, but still seems pointless I must admit. So it's like you've got 'an hour' or fuel remaining at the current consumption, rather than purely the number of miles. Just seems they went to a lot of effort to fix something that worked perfectly well already lol.

[sonic113]

I will keep an eye on this over the next few fillups to see if it does change or if it stays the way it is.

I will keep post updated in due time.

Thanks for replies.

[Celticfan]

My Mark 3 does the same. Mileage to go varies between 50 and 62 depening on my driving.

The first time I just thought they had decided to show the alert earlier.

[johnH]

I have a 1.6tdci mk3 and the light comes on at 70 miles range. But i notice this figure goes up and down with usage such as harsh accelleration, hills, wind and when the cat down the street farts lol

[sonic113]

I will keep an eye on this over the next few fillups to see if it does change or if it stays the way it is.

I will keep post updated in due time.

Thanks for replies.

I have a 1.6tdci mk3 and the light comes on at 70 miles range. But i notice this figure goes up and down with usage such as harsh accelleration, hills, wind and when the cat down the street farts lol

good to know Im not the only one fellas lol!

Thanks to all for the input here. I will keep an eye on it as I said over next few fill ups and see how it progresses.

[troy45]

I noticed similar when going from a 2006 ST to a 2010 facelift model - is it correct to say that the adaptive system is working more off an amount of fuel left in the tank than the miles to go figure?

So if it's going to throw the light on with e.g. 7L of fuel left in the tank, then going off a historical average fuel consumption figure you'll see different 'miles to go' values triggering the light depending how frugal you've been driving.

Having filled up last night after driving several miles past 0 left , the miles to go' value is pretty meaningless if those last miles are driven more 'enthusiastically' than the rest of the tank was ;)

[Celticfan]

I had a 56 plate mk2 and an 09 plate mk 2.5. They both showed the light at 50 and the beep at 25 miles. The mk3 I have it varies so I assume it's different to the earlier models.

But I have gone 'below' 0 and it still was ok.