Inverted gas mileage reading TB 2002/03

[gboos]

Hi,

first of all there are no codes or something like that. Instrument cluster just working fine. No complaints and reading is perfect at all.

The crazy part is, that the reading of the current gas mileage reading in the computer is inverted. This means, pushing the throttle gas consumption decreases, pulling the throttle the reading increases. How is the gas consumption being read or calculated and what may causing the inverted readings. Any info is appreciated.

Thank you.

Mike

 

[dwzook]

Mine reads 18mpg all the time.

 

[gboos]

Mine reads 18mpg all the time.

Fine. I just don't want to know what is normal. I would like to know what the problem is that my reading is inverted and wrong. thank you.

 

[AtlWrk]

What kind of numbers are you actually seeing?

 

[dfc739]

I thought Europe was a little different from the US in that they typically monitor fuel consumption as liters of fuel used per 100 kilometers. What you're probably seeing is the fuel mileage (miles or km per gallon or liter of fuel). The number will decrease when accelerating because you're getting fewer kilometers per liter and will increase when cruising in overdrive.

 

[gboos]

When I stay in idle the fuel consumption tells me like 28l (after a reset) or something like that. When I'm driving and pushing the throttle it goes down to 2l per 100km. When I pull the throttle while driving it goes up to 21-24l per 100km. Of course it is narrowing after some driving. But I know it should be the opposite. Pushing the throttle should increase the numbers and pulling the throttle should decrease the numbers.

But not mine

How is the fuel consumption calculated ? Knowing it, may could lead me to figure out where the problem is.

Thank you.

 

[jimmyjam]

pardon our ignorance, 99.99999% of the people here have never seen a euro spec trailblazer, so this may be a dumb question, but are you sure it isn't telling you liters/km?


I've heard the bcm calculates the mileage from injector duty cycle (calculated with injector flow at a given manifold pressure). but I can't verify that as true, its just hearsay.

 

[gboos]

First of all many thanks to your thoughts.

It's an imported US model. So no EU model (similar to Canadian model) which were just sold here for 2yrs - 2002/03. I'm pretty sure it is per 100km. Pretty sure
But it doesn't matter it's km or 100km. I just want figure out why it calculates it the opposite way around. Why fuel consumption is given lower with the foot on the
throttle and higher with the foot of the throttle.

Electrical issue from sensors ? Manifold leak ? I mean there must be one factor which is messing up the calculation.

Thank you.

Mike

 

[Blckshdw]

It's not telling you fuel consumption, it's fuel economy.

Edit: Are you sure the display isn't telling you distance per volume? (we get miles per gallon, not gallons per mile)

 

[BlazingTrails]

When I stay in idle the fuel consumption tells me like 28l (after a reset) or something like that. When I'm driving and pushing the throttle it goes down to 2l per 100km. When I pull the throttle while driving it goes up to 21-24l per 100km. Of course it is narrowing after some driving. But I know it should be the opposite. Pushing the throttle should increase the numbers and pulling the throttle should decrease the numbers.

But not mine

How is the fuel consumption calculated ? Knowing it, may could lead me to figure out where the problem is.

Thank you.

This is called instant mpg, you also have average mpg. The instant reading is calculating what your mileage is ATM and if you. Push the throttle down to accelerate you are using more fuel therefore reducing mileage. When you let off the throttle you are using less fuel therefore increasing your mileage.

Whether EU or us km/mi it works the same. It is working correctly.

 

[Harpo]

If you are in L/100km setting your numbers are all wrong,I suspect you are in miles/gallon mode.

If you are the readings behaves like you are saying,on l/100km where it actually calculates fuel consumption it should read 99 at idle.
Check your DIC settings,does it state L/100km on the DIC when in "instant" mode?.

The numbers you are telling us is indicating you are in MPG right now.

Edit:
You might be in the km/L mode that is kind of the mpg mode but in kilometers.

 

[gmcman]

Mine reads 18mpg all the time.

Have you tried resetting it? If you never reset it, after time it will never adjust. The arrow on the steering wheel when held for more than 3 seconds will reset the AVG MPG