Author Topic: UltraGauge Keeps adding tenths after shutdown  (Read 3432 times)

Offline FXSTi

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UltraGauge Keeps adding tenths after shutdown
« on: March 05, 2012, 07:08:16 PM »
I have had this happen a few times now so let me explain what I am seeing. After a <10 mile trip with heavy engine off coasting, I pull into a parking spot shut off the ignition and the trip mpg keeps adding 1/10ths until the ecu shuts down at roughly 20 seconds.

What might cause this, and how do I stop it?

Thanks

Offline UltraGauge Admin

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Re: UltraGauge Keeps adding tenths after shutdown
« Reply #1 on: March 15, 2012, 09:42:58 AM »

For the MPG to change with the ignition off, fuel usage or distance must be changing.
Put the MPH and Gallons/hr gauge along side the MPG gauge to see which is responsible.
It sounds as if the vehicle's computer is reporting incorrect values with the ignition off.

One fix would be to switch to "Power Off detect" mode 3.  See the user manual