Fuel economy tracker in dash faulty?

[mrichards]

2012 Chrysler Town and Country 81k on the clock,

Today after filling up my wife asks me why her DTE says 329 instead of the normal 422, I really didn't have an answer so today when I went to take my son to wrestling practice I notice that the average MPG was 6.2, I reset it and it started out at 1.3 then went up to like 10.x. I was wondering what goes bad in the equation here? I doubt we went from 22 mpg to 6.2 over night, everything else seems accurate as far as MPH and such. Anyone have an thoughts, ideas, comments?

 

[Run]

Sounds like someone in the house drove it like they stole it. Quick take offs and high speeds would be my guess for the sudden dip.

 

[eljefino]

It idled for 8 hours with noone noticing?

 

[mrichards]

She always drives it like she stole it So that's nothing new and it didn't idle for 8 hours even if it did I reset it when I got in it.

 

[clinebarger]

Originally Posted By: mrichards
2012 Chrysler Town and Country 81k on the clock,

Today after filling up my wife asks me why her DTE says 329 instead of the normal 422, I really didn't have an answer so today when I went to take my son to wrestling practice I notice that the average MPG was 6.2, I reset it and it started out at 1.3 then went up to like 10.x. I was wondering what goes bad in the equation here? I doubt we went from 22 mpg to 6.2 over night, everything else seems accurate as far as MPH and such. Anyone have an thoughts, ideas, comments?


I stole it while you were sleeping & flogged it pretty hard.....Sorry.

 

[Nukeman7]

Originally Posted By: mrichards
2012 Chrysler Town and Country 81k on the clock,

Today after filling up my wife asks me why her DTE says 329 instead of the normal 422, I really didn't have an answer so today when I went to take my son to wrestling practice I notice that the average MPG was 6.2, I reset it and it started out at 1.3 then went up to like 10.x. I was wondering what goes bad in the equation here? I doubt we went from 22 mpg to 6.2 over night, everything else seems accurate as far as MPH and such. Anyone have an thoughts, ideas, comments?


What is a DTE? Could the trip tracking mileage counter have been recently accidentally reset, thereby biasing the avg. over shorter miles traveled?

 

[901Memphis]

They read the fuel gauge and mass air flow so either one of those sensors could be having issues

 

[blupupher]

Originally Posted By: Nukeman7
...

What is a DTE? Could the trip tracking mileage counter have been recently accidentally reset, thereby biasing the avg. over shorter miles traveled?

Distance To Empty

 

[E150GT]

Its a computer. They probably need to be reset once in a while. I'd disconnect the battery for a bit and then see if that fixes it.

 

[Tman220]

The in dash mileage goes off a running average since the last time you reset it. Next time you reset do it on the highway with cruise set and see what it reads after several miles. And a 6.2 average sounds like a combination of a lot of city type driving, stopping, starting, and a lot of idling. Ringing any bells?

 

[Kira]

At 80K an upstream oxygen sensor could've gone bad. This will cause your mileage to drop.

Now that I'm thinking of it, would an upstream oxygen sensor going bad ALWAYS throw a code?

 

[KrisZ]

Drive the van until almost empty, refill and calculate by hand. Repeat over several tanks. Only then you will know if your gas mileage dropped or the display is malfunctioning.

 

[Oldmoparguy1]

Originally Posted By: E150GT
Its a computer. They probably need to be reset once in a while. I'd disconnect the battery for a bit and then see if that fixes it.

Do this first and see what happens. If it still does this, then the Computer may be getting faulty data from a sensor. Have you seen any other signs of problems?

 

[supton]

I've never had a vehicle with this sort of tracker in it. Do you have to hit a button when you fill up; or does it realize when it has been filled up? I mean, I'd hope an ECU can tell when the gas tank has gone from 1/4 to full. Although, it can't measure what is in the filler neck, so even resetting every time may lead to apparent fluctuations in distance to empty.

I wonder if it had been reset recently, then not driven much. Takes a few miles of driving to head towards what is normal; and then more miles for the average to shrug off any short term aberrations.

 

[surfstar]

Originally Posted By: KrisZ
Drive the van until almost empty, refill and calculate by hand. Repeat over several tanks. Only then you will know if your gas mileage dropped or the display is malfunctioning.


Best advice in here. Sort out the issue with data and facts, not speculation.

 

[mrichards]

I disconnected the battery for a few minutes hooked it back up and the DTE went back to where it normally is and the MPG jumped back up to normal, we'll see if this is a short term solution or it just needed a reboot?

 

[andyd]

The econometer on the 528e mimicked a vacuum gauge but was a combination of speed and rpm inputs. The one in my first 528e needed to be reset every so often. I wore the dash board wiring page on my ETM for the car trying to fix it. I think I have finally traced the gremlin to the stepping motor that powers the needle. Before, I thought it was haunted.

 

[Oldmoparguy1]

Originally Posted By: mrichards
I disconnected the battery for a few minutes hooked it baailck up and the DTE went back to where it normally is and the MPG jumped back up to normal, we'll see if this is a short term solution or it just needed a reboot?

Best to keep an eye on it. There may be a ground issue or a failing battery. A battery can fail quickly and it can cause all sorts of weird symptoms in our mopar cars/vans.