Scangauge II question!

I did look for some answers but couldn't find what I was looking for.

Ok so I just got myslef a SGII. Installed in a teporary spot till I have time to fish a wire into the headliner. So over the last couple of days I noticed that when i'm going 65 on the SG my MPH on my Speedo differ by about 3 saying 67-68ish, but my distance on the SG matches my ODO and the mile markers within .05ish miles for the 114 miles on tank. Do I need to tweek anything, or is my speedo just off those 3? I tryed to use my GPS but fount out that mine is not that consistant. Kept going up and down when my speed was constant, alto the distance was correct to my ODO and SG. So I did try to do the 60mph 1 mile (60sec) timming but I dont have much of any strait flat sections im my area that I can use to time it. Secondly If I do adjust the speed does it effect the distance? (thinking yes)

I think that the spedo is off(most are) but need my suspitions confirmed.

Any answers is appreciated, Thank you in advance!
J.

Oh ya for anyone that has id it hard to get a cable up the A-piller into the headliner?

 

The speedo in the 09 Tacoma is off a couple mph. It seems to be a widespread problem. It has been mentioned in a few threads. It's probably still within their specs but it's off more than a speedo would usually be off. I noticed mine was off via GPS.

 

I wouldnt tweek anything it says in the manual that the first fill up your mpg avg will differ from what you actually get. So maybe it will be closer after you the first fuel up.

 

You need to check the scan gauage against a known standard to be able to answer your question. You can adjust the SC by either the speed or distance as they are related. For accuracy sake , I would check mile markers over more than one mile. Maybe a 10 mile stretch.
GPS checking using distance is good, but you need to be on relatively straight roads, because the GPS samples satellites every 1-2 seconds, you are actually getting chord distances when you round a curve , not arc lengths. Over a 10-15 mile stretch , on straight roads , it would not matter much, city driving would be way off.

 

I just know that on my previous car my 2 forms of GPS(radar detector displays it and my Garmin navi) were always dead on with my speedo. So it really stuck out on the Taco.

 

The scangauge pulls the MPH directly off the ECU. So, the MPH you see on the scangauge is the data that is IN the computer.

The data you see on the speedometer on your dash does not match the data in the computer - and that's probably because the DIAL on the dash speedometer isn't calibrated properly.

Don't adjust anything....it's completely normal.

When you use a GPS to compare - it should match the scangauge MPH (which is accurate to the data inside the ECU).

Atleast, that's what I found on my 07.

 

Cuseman18 Not to sound like an A$$ (i'm not) but you may want to reread my post, I never mentioned MPG!!!! I am talking about the distance on the ODO (TripA reset each time i fillup) to the SG tank miles matches with in a 1/10 of a mile. now its hard to tell as I passed 100 miles on it. A not so nice surprise when I got home and can't compair now.

mcgiiver, what I figured Id have to do. I'll wait till the weekend when I have the time to take some time on the interstate and check my distance that way against the mile markers, but looks to be just about bang on.

Janster (best info thanks) Makes sence too. and kinda was one of my thoughts was the dial needle was not on the pin right. therefor making the Spedo off! Its a good thing the ODO is not like my spedo saying I went 1mile when I actly went .9miles. phew!!!

A would not mind coming across one of those radar trailers the cops have that tell you "Your speed is" radar signs things, but I never can find out where it is setup at. If when I do then I would be 99% sure.

My GPS sucks, should have spent more and got a better one.

I do go to Canada alot so if I change it to KM when i cross will it mess it up when I switch it back to miles???

 

installed my cable a few months ago. piece of cake. do a search and you will find an excellent post with pictures on how to take the pillar cover off. once you do, there is plenty of space to place the cable, and a nice opening at bottom of "A" pillar, to route cable to your obdII connector. start the cable at the mirror end, open up a headliner a bit with your fingers, it will hide nicely. hold the headliner away a little bit with your fingers as you place the cable underneath. there is plenty of room.

 

Ah cool, I did keep searching and did find out how the pillar cover comes off but was not sure if i had to fish the wire across! Being able to just tuck in the cable along the front edge of the headliner is awsome, didn't even think of that!! I made a cat5 cable with a rj45 block on one end and a plug at the other end. So I wont have to take out the wire if i ever want to use the SGII in any other car/truck.