How-To: Program your Scangauge to work on the smart CDI

[smartzuuk 167]

Programming the Scangauge takes only a couple minutes, and if you get it set up properly, the fuel economy numbers it displays should be within .1 L/100 km.

Key settings:

FUEL TYPE: DIESELa

TANK SIZE: 24 litres if you fill to the shutoff, 25 if you fill to the top and can visually see the fuel, and 28 if your name is Eddie. (PS - tank size does NOT effect fuel economy!!)

ENGINE SIZE: 0.8 litres

SPEED: +3% for stock size wheels/tires. This calibration affects speed and distance. Using 3% should result in a near match between the distance showing on the Scangauge and a GPS unit. Also - the scangauge should match the ODO in the car to within 1%. (FYI - the smart speedo does normally read faster than the actual speed you are going.) If you are using tire/wheels sizes other than stock, you may need to change the SPEED adjustment slightly. My Corelines with 175/195 needed a 5% adjustment factor to match a GPS.

FILLUP: It is suggested at this time that you key a +5% adjustment factor here. This number was determined after multiple fills at the same pump in my own car with the Scangauge showing 0% adjustment. After the 5 fills, I calculated the total fuel actually pumped, and compared it against what Scangauge had said I used. That is where this adjustment factor came from. It is not recommeneded to adjust the Scangauge at each fillup - other than to press 'DONE' when you do fillup, so the tank resets and starts keeping track from scratch again. Advanced users may wish to verify their own 'fillup adjustment factor', and calibrate their unit against their car and/or driving style.

UNITS: I suggest you use KM, LITRES, CELCIUS and PSI. Please note: LHK = litres per 100 kilometres.

I may have forgotten a couple bits and will review this later today to be sure it's complete.

[smart65 28]

I set the speed adjustment to 3%, as suggested, but found that the Scangauge was reading higher than the car's speedometer. Since most speedo's are optimistic, I expected the opposite. When I changed it to -3%, the Scangauge's reading was the lower of the two. I don't have a GPS to check it against. Did you mean to say -3% instead of +3%?My first fillup after the initial one. required a 16.9% adjustment to match the number of litres actually pumped. Part-way through that tank, I had changed the tank size from 22 to 25 as per your post. This might have confused the computer for that tank. I always fill to the lip, and have been getting numbers that lead me to think that 22 litres are consumed when the smart's display shows 0.0 litres. I know from ClubSmartCar posts that there is a small amount of fuel still available at that point, but I thought that the amount was only enough to travel about 40 km, which would be about 1.5 litres. Using 25 litres for the tank size implies that the "hidden reserve" is 3 litres, which should be good for 60, 75 km, or more, past the 0.0 point. Also, the Scangauge manual specifically says that a low estimation is preferable to a high one (eg. in reference to a 17.5 litre tank, it says "use 17"). Would you comment on how you arrived at the 25 litre recommendation?

[danno 0]

I set the speed adjustment to 3%, as suggested, but found that the Scangauge was reading higher than the car's speedometer. Since most speedo's are optimistic, I expected the opposite. When I changed it to -3%, the Scangauge's reading was the lower of the two. I don't have a GPS to check it against. Did you mean to say -3% instead of +3%?

With mine set to +3%, the scangauge shows lower than the speedo.

[smart65 28]

I'm running with Blizzack tires (about 9,000 km on them). Are you using summer tires? If so, would that explain the difference?

[danno 0]

Nope, winter Continentals, about 2,500 km on them.

[smart65 28]

On pages 16-17 of the Scangauge manual it states "Positive values of % will increase the displayed speed. Negative values of % will decrease the displayed speed.".Since I don't have a GPS, I feel that I'd be better off to change the SPEED adjustment back to 0%. Then the display will match the car's speedometer. I've also noticed that the TANK KM travelled number is lower than the car's odometer by 3% (290 vs. 300, at present). I assume that changing the SPEED adjustment to zero will also correct this mismatch for the next tank. It appears as though the Scangauge computes the number of kilometers travelled by using its SPEED value as one of the factors in the calculation. Even if the car's computer numbers are slightly out, I'd rather have the Scangauge numbers match, than produce a second set of numbers which disagree. I will have to continue to treat the car's odometer as gospel for warranty and service purposes, and my Spritmonitor fuel records have been based upon that source until now, so I will also continue that practice. What advantage would I gain by not reverting to the default 0% SPEED adjustment?

[Awesys 4]

The advantage I guess would be that you would have a number that matches a GPS speed. There isn't that big of a difference really. On mine it usually is just 2-3km/h off.

[Guest kwaldron]

There is a trade-off. If you want very accurate L/100K figures you're going to have to ignore the vehicle's odometer and go with an adjusted, and confirmed accurate Scangauge. Doing that ensures that the LKH displayed by Scangauge is accurate at any time. Or you can choose to have Scangauge match your odometer, speed, etc. in which case you have a consistent set of readings all round, albeit inaccurate.

[MikeT 744]

I thought the smart's odo was pretty accurate, or so I had read somewhere.....Of course the speedo is set to be optimistic.

[bilgladstone 13]

I kind of get it that the SGII somehow polls the ECU and sets the "current mode" protocol automagically, but after asking a couple of people, I get conflicting news that the protocol is either KWPS or ISO. Can anyone nail this down for me please?B:sun:

[smartzuuk 167]

I definately do not mean -3%! In fact, to make the Scangauge 'speed' match the car's speedo, you would need to add 5 or 6%

SPEED: +3% for stock size wheels/tires. This calibration affects speed and distance. Using 3% should result in a near match between the distance showing on the Scangauge and a GPS unit. Also - the scangauge should match the ODO in the car to within 1%. (FYI - the smart speedo does normally read faster than the actual speed you are going.) If you are using tire/wheels sizes other than stock, you may need to change the SPEED adjustment slightly. My Corelines with 175/195 needed a 5% adjustment factor to match a GPS.

I could offer a more lengthy explanation, but for now, I'd suggest adjusting it to +3% and then compare the ODO (not the speedo) against the Scangauge after a 30 km trip. By making this adjustment - the distance shown in the Scangauge will be very close to that of a GPS.

The car's ODO with stock tires/wheels is within 1%, however, the SPEEDO reads close to 3% too fast. Which translates into 2-3 kmh at highway speeds.

Bil - I don't think knowing if it is ISO versus some other format will greatly assist Roland program the X-Guage. I think you will still need other codes that aren't readily displayed.

[smartzuuk 167]

There is a trade-off. If you want very accurate L/100K figures you're going to have to ignore the vehicle's odometer and go with an adjusted, and confirmed accurate Scangauge. Doing that ensures that the LKH displayed by Scangauge is accurate at any time. Or you can choose to have Scangauge match your odometer, speed, etc. in which case you have a consistent set of readings all round, albeit inaccurate.

Not exactly.

The smart speedo and ODO are nearly 3% different - you have to choose which one you match. The odo is the better to match out of the two - and choosing to match to your ODO over say a 30 km trip (in the absence of a GPS) is an acceptable method. Start with the Scanguage showing 0% for speed - reset the current trip, reset your car's trip meter, and go for a drive... now review the ditances on both, determine the difference, and adjust the Scangauge accordingly to match the car. (We know that the car ODO is within 1% with stock tires.)

[MikeT 744]

We have to think of significant figures (remember physics?) when deciding how anal-retentive to be about calibration.Remember too that tires' circumference changes as they wear, which will make the odo and speedo over-read even more, assuming that both do when the tires are new. I would suggest that losing 6 mm off the tread of a tire (from new to barely legal) makes a 2.1% difference all on its own on a fortwo.So accepting the car's odometer as "gospel" may be the best policy, unless you enjoy re-calibrating things to the Nth degree, on a regular basis, to compensate for tire wear .

[Eddie Eddie Eddie 1]

I prefer the 3% adjustment for speed/distance...It perfectly matches my gps readout for speed... Which also matches those dot-matrix signs on the road that tell you how fast you're going...Yes my odo and the SGII don't match... But the slight difference is too minute to bother with.Eddie

[smartzuuk 167]

And to tell you this - all my spritmonitor are off the smart ODO with no correction.

[rwelte 0]

Hi guys,Can some of you ScanGauge owners put a list together of all the generic engine parameters that the ScanGauge will reveal from a CDI's ECU (Engine Load, Coolant Temp., etc., etc.)? This would be really interesting (if discussed already in some thread before, please post the link).Many thanks,Roland

[rwelte 0]

OK, after reading through all the massive ScanGauge threads in this forum I've found the information that I was looking for (generic ECU parameters of fortwo CDI).

Regards,

Roland

[mixed 1]

The last two times I have removed the scangauge from the car it has completely reset to defaults...... 3.0l gas engine etc........ and I have had to re-input all the data from scratch and save it again ............ anyone got any ideas what I am doing wrong or why it may be doing this ........ I will admit that I have as yet not read the entire manual but it seems somewhat peculiar that it would do this........... when it hadn't previously.

[smartzuuk 167]

I'll check mine today and see. I didn't think those settings changed.

[ValgardForkbeard 2]

Didn't someone else have an issue with it resetting when they un-plugged it, and it seems to have been that the plug was not fully engaged in the socket.MG

[Guest kwaldron]

The other thing to remember is that in the winter with the air so dry static electricity is much more prevalent. It is quite possible that a static discharged could have caused a reset. This was very common in older computers.

[smart65 28]

I was the one who had a reset occur when the ScanGauge was moved while it was operating. In that case, the unit reset to defaults because the plug was not fully seated in its receptacle. A member advised me to avoid modifications to connections in any electronic circuit while the unit is operating. Transient voltages may occur which can cause unexpected things to happen. If the unit was off when unplugged, it should not have reset.

[strawboss 5]

Does anybody know where I can get the codes to program an xgauge function to readMPG in Imperial units?I've emailed the company but no response yet, & a google search was not successful.I just don't have the "feel" for LHK

[smartzuuk 167]

I think you e-mailed me today. You can't get MPG imperial directly, but you could create a FILLUP adjustment of 20.1% lower than your current amount. Be careful to subtract 20.1% from the total, so if you have a +10% factor already to make the LHK accurate, you need to reduce by 22.1%

Edited July 23, 2009 by smartzuuk

[strawboss 5]

I thought this fillup adjustment was a trip function,like "time to empty"& so on, an adjustment may give me an average FE reading for the tank, but not what I want, which is a real time display. Oh well.