Page 1 of 1

VSS reading and actual vehicle speed are miles out?

Posted: Mon Oct 23, 2006 9:58 am
by fonz600
Does anyone know why the VSS on my Kpro (JDM ITR 04') and the actual speed my speedo reads are miles out?
For example flat out in 3rd and my VSS is reading 55mph which is way off of what I'm actualling travelling.
I have the gear ratios setup correctly on Kmanager so it ain't that.
Any ideas?

Posted: Mon Oct 23, 2006 3:23 pm
by Hondata
The speed as calculated in the ECU is dependent of the speed sensor signal and nothing else. What the exact difference in speed between the gauges and datalogging?

Posted: Tue Oct 24, 2006 1:34 am
by fonz600
I'll do a run today and take a note specifically what the speedo is saying.
Kpro also never displays the correct gear I am in. Could this have something to do with it?It always shows 2nd when I'm in 3rd or 4th. It always reads gears lower than what I am in.

Posted: Tue Oct 24, 2006 4:05 am
by fonz600
Just had a brain wave. I live in UK and got a JDM import where I believe a speed delimiter woulda been fitted.
Could this be working in a way that fools the ECU the car is actually going slower than it is to allow the car to go faster than the limiter is set at?
If so can Kpro get round this problem? By correcting the value if it is out a certain percentage?

Posted: Tue Oct 24, 2006 5:04 am
by scottishpol
speedo convertor is your problem!

Probably fitted at the gearbox vss.

This is a common problem with all jdm imports in the UK.

It will be messing up your gear correction factors as well.

Posted: Tue Oct 24, 2006 6:48 am
by fonz600
scottishpol wrote:speedo convertor is your problem!

Probably fitted at the gearbox vss.

This is a common problem with all jdm imports in the UK.

It will be messing up your gear correction factors as well.
Kinda thought that in the end. Any way of correcting it without removing the convertor tho?

Posted: Tue Oct 24, 2006 3:28 pm
by scottishpol
The only way round it is to wire the convertor at the back of the cluster.

Posted: Tue Oct 24, 2006 5:14 pm
by fonz600
scottishpol wrote:The only way round it is to wire the convertor at the back of the cluster.
Really? Feck that hassle. I can live without it. Cheers for that mate. By the way looking at your username, I'm just wondering if u r Scottish? As I am.

Posted: Wed Oct 25, 2006 5:46 am
by scottishpol
Yep, born and bred :D

Just be aware that all ecu gear, and vss based corrections will be getting an incorrect vss signal (kph/1.607~).

Posted: Wed Oct 25, 2006 7:10 am
by fonz600
I'm guessing most cars in Uk running Kpro will be having the same problem too tho huh? I might take a look at it but dunno what was fitted as bought the car already passed SVA etc.
I'm from Fife mate. Where you based?

Posted: Wed Oct 25, 2006 9:04 am
by Hondata
Any speed converter must be wired between the engine wiring harness VSS output and the gauges, not between the speed sensor and ECU.

Posted: Thu Oct 26, 2006 6:20 am
by scottishpol
Fife as well