ScanGuage Set Up

[goldie]

I am seriously considering purchasing a scanguage for improving fuel economy. I am looking for advice and hints for setting up and using the guage. My vehicle is an 07 Sierra with the 4.3L and a 5 spd. manual. If anyone has experience with a similar vehicle I would appreciate hearing from them. Especially what the guage did for improving mileage.

[theholycow]

I have a 2002 Sierra 5.3 auto. Depending on if you plug in the SG while the truck is off or on, it may scare you by disabling your gauges; no need to worry, unplug it, turn the truck off and back on, and the gauges come back. I can't remember whether that happens if you plug it in with the truck running, or with the truck off, but whichever it is you just have to do the opposite.

Other OBDII devices cause similar behavior; I have a cheap OBDII code reader that, if I plug it in while driving, will cause my gauges and radio display to die for 5 seconds or so.

Beyond that, there's nothing special about setting it up for the Sierra. Just follow the directions and/or advice you read in various forum posts. Set engine size and gas tank size, then adjust it every time you fill up.

There are XGauge codes that you'll be able to use. I started a thread full of them, but the codes I made were for older VPW-protocol GMs; your 2007 is probably CAN-bus and would need the codes altered. Anyway, I was concentrating on getting automatic transmission data so a lot of them won't help you.

[Jay2TheRescue]

I use a Scangauge on my 1998 GMC Sierra K1500 5.7L. Works great, but there is a slight thing where the SG keeps resetting the dashboard clock, but nobody else I've encountered has had similar issues. Its nice to keep an eye on the mileage and other data while driving so I can make changes as necessary.

[theholycow]

Jay, are you leaving it plugged in or unplugging/re-plugging it?

[Mr Incredible]

I've used mine in my 98 Z28, the 99 F250 V10 Super Duty, and the wife's Prius. It worked well in each.

It helped my economy best by giving instant feedback of my pedal control and how it was affecting my mpgs. It helped most in the truck by showing me the best mpg speeds. I knew them, but this showed me in solid numbers. That worked well with the Camaro, as well. The engine and transmission are tightly tied together in it so there isn't much to be gained except pedal discipline (which is not easy.) In the Prius it gave a better feedback of gliding and electric-motor-only driving. I managed 52+ mpg on a trip to KC and back, which is the best I've been able to manage in it. The type of traffic I was in was the best for Prius driving, so that helped a lot.

It was very helpful in finding the sweet spot when following behind bigtrucks.

Mostly, though, it's just positive feedback to keep your mind right.

[JanGeo]

Speaking of SG has anyone sent their ScangaugeII back for the software upgrade??? How long did it take from sending it out to getting it back?? My xB is going to be in the shop getting the body fixed for about a week so I figure I would send it out for the upgrade - I have a really early SGII.

[Jay2TheRescue]

I leave it plugged in. When I first got it it would reset the dashboard clock every time the truck was started, and if I disconnected it the dashboard clock would keep time. After a few weeks that stopped though. Don't know what I did to change it. Anyway, I took the SG out to plug it into another car for a trip, and when I put it back in the truck (About 3-4 months ago now) its never stopped resetting the clock. I also recently noticed that I can't use the in dash CD player while the SG is plugged in for some reason. If I unplug the SG, the CD player works fine. Plug it in, and I can't play or eject a disc. Strange... I don't use the CD player much though, maybe only 2x or 3x /year so my largest inconvience is the clock resetting. I mostly use the radio, but on trips I use my mp3 player. I've emailed SG about it, and they sent me a generic recheck your settings email. I replied back, saying I've checked everything else, but never heard back from them. I figure I'll live with the clock resetting, and when I eventually buy a new(er?) DD, the SG will go in the new vehicle, and The Beast will assume beater status, and I don't care what kind of mileage my beaters get, as long as they run well.

-Jay

[theholycow]

I thought of a couple more things:

- If you EOC, you'll want to set the ScanGauge's engine type setting to "Hybrid".

- The SG shows DFCO as "9999" on the instant MPG reading. However, it takes forever to display it; when I know I'm in DFCO, the SG still takes a good 3 or 4 seconds. If your 4.3 is not programmed better than my 5.3, it takes 8 seconds before DFCO kicks in; combined with the SG's delay, you will never see it unless you're DFCOing down a mountain.

[Jay2TheRescue]

I find that better indicators of DFCO are to set a gauge to either timing advance, or to read one of the O2 sensors. In DFCO the O2 sensor will read 0, and timing advance will read -10.

[BEEF]

won't it also read open loop? that way it is ignoring the oxy sensor.

[theholycow]

Does the SG report those things with less lag than MPG?

[Jay2TheRescue]

Mine will indicate these within a second, but I have mine set to update info at the fastest rate.

[goldie]

Many thanks for all the info! Everybody's response has been a great help. However, I'd also like to know what do the acronyms EOC and DFCO mean. Also, it may be awhile but rest assured I will post my results after I've used the ScanGuage awhile. Again, thanks...what a great site!!
Tom

[bowtieguy]

Engine Off Coasting

Deceleration Fuel Cut Off(or something close)

the first is self explanitory. the second, for most new cars, occurs when you coast engine on in gear above 1k rpms. at 1k rpm, DCFO ends to maintain idle. so, coasting in gear allows little or no fuel usage.

[goldie]

Many thanks for the information. When I coast it is usually in neutral and for the most part my tach stays at about 1K. Does this mean the engine is in the DFCO mode?

[theholycow]

You can't DFCO and be in neutral. DFCO requires the engine to be turned by the road so that no gas is required to keep the engine running. DFCO happens with the vehicle in gear, rolling, above 1000rpm, and your foot entirely off the gas pedal (and may not always happen even under those conditions, and there may be a delay before it starts).

[bowtieguy]

i use DFCO and neutral coasting depending on application...

when driving around town(back roads) at lower speeds and rpm, i use neutral coasting because it enables me to glide a greater distance and because DFCO would end quickly in gear. this application is a low(sometimes zero) traffic one.

on the highway, at higher speeds and rpm, i use DFCO as the rpms take longer to drop to 1K. i use it on hills, off/on ramps, and approaching red lights.

concerned about ignition wear, i've only been using EOC to end a trip. there are long, low traffic situations both getting to work and home providing great EOC opportunities.

[goldie]

More thanks for some good information and furthering my continuing education about such matters. Here's another request; which method, as mentioned by bowtieguy in his first two paragraphs, has the biggest effect on saving fuel?

[theholycow]

It really depends on a lot of factors, and the best way to find out what works for you is to experiment. Here's a few guidelines:

If you intend to slow/stop, as when the speed limit lowers, you approach a stop sign/red light, or you gather speed down a steep hill, you should DFCO.

If you don't plan on losing any speed, you should neutral coast, or if you're comfortable with it and your car is ok with it, you could EOC.

Keep in mind that you need to study your car's DFCO behavior before being sure it works when you expect. There are requirements for speed, RPM, accessory usage, what your most recent actions were (accelerate/cruise/shift/whatever), if the engine is fully warmed up, and so on...and then there could still be a delay before it will DFCO, which would make short DFCOs counterproductive.

[bowtieguy]

i concur w/ HC...

when travelling a road @ 25-30 mph, i'll neutral coast if space/traffic will allow. i accelerate to ~35mph(25 mph speed limit), then neutral coast to a stop sign on my route to work.

once on the highway(55mph), i stay in gear. when approaching red lights, on/off ramps, and down hills, i practice DFCO.