Speedometer inaccurate...way off

[Noridetoolow]

Searched and read a handful of threads but cannot seem to find someone that has\had the same problem. My speedo ( on my newly purchased 92 EX Accord ) is off by about 20 mph. Read 0 at rest but I know at 50 mph im really doing 70. Have not looked at lower speeds as much so not sure if its 20 off or a high percentage off. Could the VSS cause this??? Even Googled and Yahoo'd this with no luck whatsoever. Cruise works, tach everything is fine, speedo just reads lots lower than actual speed.

thanks all

[visualpoet]

What size tires are you running? Has the tranny been swapped?

[Fleetw00d]

I'm assuming you have a reasonable tire size. Is it consistant or does it jump around? How do you know you're doing 70, are you using GPS? Does the odometer register correctly or is it off as well? If their both off, it is probably the VSS. If the odometer is correct, then it is probably the speedometer itself.

[Madpol]

yeah mine is also off...my spedo can be reading 60kmh but im actually doing 55kmh and its been the same with the factory wheels i used to have on it.

i personally think its a government thing and its also been said in the news that speedo's are being calibrated wrongly on perpose so we are actually driving slower than we think. and its all to do with the less accidents on the road thing and people having a better survivability rate.

[Fleetw00d]

They are probably required by law to be within a certain amount (don't know what that is off hand, particularly in NZ). Three of my four are within 1 mph of GPS speed. My EX is about 2 low at 60 mph). Does the same ratio hold over the whole range (reads 30 when doing 27.5 or 120 when doing 110) or is it always 5 high? Does your odometer read correctly (vs. GPS or highway kilometer markers)? The longer a distance you check over, the better.

[AeyJayCB7]

Check to see if your VSS sensor loose. Also if you think its the VSS sensor visit your local junkyard for VSS. I heard Ebay VSS sensor work but for only short period of time..

[Noridetoolow]

Def not wheel and tire combo, 20s wouldnt even throw it off that much lol. Not sure if it's effecting the odometer, will watch it tomorrow and see how it does. It doesn't fluctuate and it SEEMS to be more of a percentage off instead of a solid 20mph off. Had a buddy following me after I bought the car, was wondering y I was flying past everyone on the interstate when I was only doing 55, he said I was doing 75. Rests at 0mph at idle but is increasingly off the faster I go. I'll watch it in the morn and see what I can figure out. Thanks all

[Madpol]

yeah sounds about right with the faster you go the more inaccurate the spedo is...i was driving home after my xmas holiday doing about 120kmh on the motorway(highway for you americans lol) coz i knew my spedo was out and i got caught by a speed camera doing 107kmh...so yip its weird and seems to go on a percentage.

[Noridetoolow]

odometer ( specifically the trip odom ) is dead on. So its JUST the speedo from what I can tell but I will look again this afternoon. I commute 1.5 hours to work and my test this morning was 68 miles, ill make it longer this afternoon. Dont know about a tranny swap, just bought the car and only thing i know is motor was swapped in December 2010. Saw ( and am getting ) the receipt for the motor but it was motor only. Car has 191,000 original miles but shifts and drives great.

[s.green]

At least your speedo works! I only have the tachometer to work with and I don't even know how accurate it is. my odometer doesn't work either. The crusie control wouldn't work if the VSS was bad so maybe it's about to give out. I don't know if they just go out at once or if they can slowly fail.

[Tippey764]

Yes i know this is an older thread

At least your speedo works! I only have the tachometer to work with and I don't even know how accurate it is. my odometer doesn't work either. The crusie control wouldn't work if the VSS was bad so maybe it's about to give out. I don't know if they just go out at once or if they can slowly fail.

All of those problems are tied to your VSS. When a VSS goes bad it becomes intermittent, only sometimes randomly working until it just fails altogether

[93blackcb7]

speed sensor????

[Noridetoolow]

I grabbed another VSS while at the junk yard the other day but have not tried it out yet. Too many things going on at once, LOL

[H22Artman]

there are potentiometers in the gauge cluster.
if the cluster has ever been out or replaced and those have been messed with it can easily throw the reading off.

i had some trouble with those a while back. look for my threads on it. i cant remember what they might be titled.

i now have them adjusted so they are more or less accurate.