2011 Fiesta Titanium 1388 petrol. The "average speed" and "average mpg" have reset (themselves). All other functions are OK. Why would that happen? All I can add is that this is a low-mileage car (49,000) and I don't use it often...last refuelled August 2017,...yes, that's right August 2017! The trip-computer tells me I have "84 miles" range left! Ideas?

Has the battery dropped very low while the car has been unused?  The memory for these is only 'short term' so resets if the voltage is lost. They aren't stored in the same place as the mileage which is a 'long term' memory.   They may even reset after several months of no use.

The range is not stored anywhere but calculated when you switch on the ignition.

Thank's...The battery may have dropped but never to the extent that the car would not "start". I start (and run) the engine every 3 or 4 weeks...for 20 minutes, mostly on idle, occasionally increased to around 2,000 rpm. The battery is "original", so 8 years old. I guess I should "get out more often"!!! Your answer makes a lot of sense, thank-you.

2 hours ago, JimmyDouglas said:

Thank's...The battery may have dropped but never to the extent that the car would not "start". I start (and run) the engine every 3 or 4 weeks...for 20 minutes, mostly on idle, occasionally increased to around 2,000 rpm. The battery is "original", so 8 years old. I guess I should "get out more often"!!! Your answer makes a lot of sense, thank-you.

Starting the engine takes priority when the battery is low, the voltage can be taken away from other modules at that time, meaning some modules lose voltage even though the engine still starts.

Just out of interest though, how do you use the car so rarely? The fuel will go stale before you finish that tankful!  

My Mrs does very little mileage and we have had all sorts of minor electrical glitches like this over the years. As mentioned on another thread recently, stop-start systems are also prone to acting up under such circumstances, though I don't think your model has that? Would recommend taking the car out for a drive now and again, rather than letting it idle while stationary and perhaps topping up on a "little and often" basis, to get some fresh fuel in there from time to time.

 

On 4/22/2019 at 1:11 PM, TomsFocus said:

Just out of interest though, how do you use the car so rarely? The fuel will go stale before you finish that tankful!  

Thanks for that. Regarding your question...I will be 64 this year and have had to take early-retirement, on health-grounds. The car is kept in my garage. I bought the car in 2015 and mainly used it to and from work (14 miles per day). I guess I really don't need it, anymore!

19 hours ago, Eric Bloodaxe said:

Would recommend taking the car out for a drive now and again, rather than letting it idle while stationary and perhaps topping up on a "little and often" basis, to get some fresh fuel in there from time to time.

 

 

1 hour ago, JimmyDouglas said:

 have had to take early-retirement, on health-grounds. 

Sorry to hear that, James.  Similar position with my Mrs but she's hung on to her car for the feeling of independence and we manage to keep it ticking over between us - put petrol in all of 4 times a year!😀