problem with scangauge 2

[light-foot]

I'm from Arizona and the temperatures have started to get around the high 60's and the low 40's. this is the second day in a row my scangauage 2 resets all the current information such as miles, fuel consumed and hours till empty. is it supposed to reset those readings? Is it cause of the cold temps or is it a defective scangauge? Ive had it for over two months and now this happens. someone please help.

[smartzuuk]

Start with the basics. Have you unplugged the unit from the OBDII port at all?

[light-foot]

havent unplugged the unit since i got it.

[JanGeo]

It usually keeps the readings even when unplugged - make sure someone is not pressing the reset buttons by mistake. Check your car battery terminals too.

[MetroMPG]

I wonder whether it's got flash memory or a little battery for memory storage when off. (Like how computers lose the ability to keep time when the internal batt wears out.)

[JanGeo]

I didn't see any battery when I took my SG1 apart so I think it is flash. Batteries in a car enviroment is not a good design espically on the dash area.

[Silveredwings]

Correct me if I'm wrong, but I don't think the OBDII port is required to supply power when the ignition is off. If that's the case, then the only think that would persist power would be either a battery (unlikely), or a capacitor used to filter the voltage supply. BTW, could a lower voltage cause the SG to dump memory? Possibly a lower temperature could affect the chip and support circuit.

It seems to me you could solve (or greatly reduce) this problem by feeding the SG through a diode (a kind of one-way valve) with a larger filter cap on the SG side of the diode. When the ignition is on, it charges the cap until full. When the ign is off, the cap discharges through the SG. Size the cap according to the SG current draw and how long you want it to keep alive. The diode keeps the cap from 'feeding' back to anything else in the car though the OBD port.

[JanGeo]

The port supplies power all the time and when you plug in it powers up and tried to connect. Plus the menu buttons work all the time - it just goes to sleep when left alone for a while without the engine running.

[light-foot]

i don't get it. it's plugged in. the only information I lose and gets reset by itself is the distance, fuel consumed and the time till empty. luckily I live about a mile from linear logic. maybe I should inquire to them.?

[JanGeo]

Yeah it sounds like a fillup reset.

Hey ask about the plug-in data recorder option they are working on if you go there.