speedometer is off - Toyota Nation Forum : Toyota Car and Truck Forums

specter692000 · 08-31-2010, 08:16 PM

Ok first post with a weird problem. The problem is that my speedometer is off by 3 MPH and by off i mean when it reads 60 MPH its actually doing 57 MPH. I have a tomtom GPS and thats how i figured it out.

Any way to fix with out having to go to the dealer or is that the only option.

specter692000 · 08-31-2010, 09:22 PM

if im just being worried over nothing just say so i can take it. trust me if you go to s10forum.com you'll see what all goes on there.

***Kiwi-Corolla*** · 08-31-2010, 09:29 PM

Have you got the OEM wheel and tire sizes on your car? Some manufacturer's actually improperly adjust the calibration from factory on purpose to help you avoid speeding fines etc, but generally it will only be out by a 1 or 2 MPH. You can get your speedo recalibrated quite cheaply. Some places will check it for free and tell you exactly how much it's out by, and then charge a small fee to calibrate it properly. Would pay to do some phoning around, as it would certainly be cheaper than getting the dealer to do it.

specter692000 · 09-01-2010, 10:50 AM

thanks for the quick reply didnt know that dealers used that trick.

From what i know its the replacement wheels that are the right size.

Stevo_Echohb05 · 09-02-2010, 11:00 AM

Quote:

Originally Posted by specter692000

From what i know its the replacement wheels that are the right size.

You can always check the size listed on the sticker on the door and compare it to the tires.

alfiejts · 09-07-2010, 01:18 PM

I don't think you have a wierd problem.

Every car I have ever had has had a speedo that under-read by a small amount - its just that until we had anything like a satnav to check them with, we didn't know.
Firstly, when you work out the different circumference of a tyre with full tread depth to one with minumim tread depth - that's a 2.5% variation, so there's going to be that anyway.

I don't know abiut US law, but the UK regulations insist that the speedometer can under-read by up to 10% but must not over-read.
So that means that to comply with the law, the manufacturers aim for the speedo to under-read by 5% to give them a small manufacturing tolerence either way.

And also in the UK, Police traffic patrol cars used to be fitted with separate accurate speedometers for prosecution purposes, because the standard fit speedometers weren't accurate enough...

So given the manufacturing tolerences and the variations caused by tread depth, I'd be surprised to see any car with a perfectly accurate speedo.

Just do like the rest of us - drive a couple of MPH over the speed indicated by the speedometer in the knowledge that you're not acually breaking the speed limit....

specter692000 · 09-07-2010, 03:55 PM

well i picked up the featured product thats on the site the OT-2 and was checking the sensors that i can and the VSS shows 57 when the dash spedo was sitting at 60 so when i head to the local toyota dealer on friday i'm going to see if they can set it proper for me.

2005RS · 09-10-2010, 09:03 AM

I'm curious to see what they can do for you. my speedo under reads about 7km on 2005 echo with stock tires. never worried about it much, but if it's an easy fix...

specter692000 · 09-15-2010, 04:28 PM

totally forgot about it the other day when i was there but going in friday to get rear breaks replaced and a new rim because of a bad one causing vibrations, Just have to remember to tell them.

JNEG · 09-15-2010, 07:14 PM

I'm with alfiejts on this one; the way troopers are throwing out speeding tickets like confetti these days, I'll take the built in safety margin!

specter692000 · 09-21-2010, 06:59 PM

yea i know what you guys are saying about the buffer but the majority of the time im running with traffic and thats about 5-8 MPH over the posted.

But he is what they told me "no matter how many parts we change there will always be a 3-4 MPH off" or as i took dude leave us the hell alone with that nonsense. I know that my 91 s10 had read the correct speed from day one of me owning it so they just dont want to mess with it.

Solace87 · 09-23-2010, 11:14 PM

3 off by 60 is lucky. Almost any car is off by that much at that speed. Very common in these cars, in fact that feature is 'stock'

tstclr · 10-31-2010, 07:12 PM

My 04 Echo shows 120kph when I'm actually doing 115. I wonder if this also affects the Odometer? If that's the case my car has less KM's on it than the odo shows..

specter692000 · 11-02-2010, 06:53 PM

ok guy i'm going to ask this in my thread has nothing to do with the speedo but I keep getting the fun P0420 (catalyst system efficiency below threshold B1) code and i know its such a broad ass code that i dont want to throw unnecessary money at it

When I fill up my tank drive a few miles check engine light comes on (P0420) clear it and then at or about 1/4 tank gone code pops back up, I clear it then at or about half a tank pops back up. I think its just the gas cap because when its cold it takes longer for the code to pop up any thoughts.

I do plan on taking care of it when i get the cash and time just want some outside impute and dont want to pay a dealer $53 just to run it when the light isn't on.

2005RS · 11-03-2010, 09:42 AM

not so sure about it being the gas cap. the timing of when the light comes on may be a function of the engine and exhaust warming up.
sounds more like a cat or O2 sensor (I'm not a mechanic, but see the link for what I read) http://www.aa1car.com/library/p0420_dtc.htm