Speedometer Jumping (possible bad VSS) - Honda Prelude Forum

ludedood97 · 06-29-2004, 10:15 PM

I'm throwing no codes. I just did this swap with the lsd tranny. Intermittently now my speedometer will quit working, the needle will just bounce up and down. Seems like though after i let the car cool off then start it back up it works for awhile. Maybe thats just coincidence. But when the needle starts going wild VTEC will engage but no real noticeable power output is shown. Are these symptoms of a bad VSS?

Gerhard · 06-30-2004, 01:40 PM

Well, if you were here I could hook the car up to the diagnostic computer and we could see if the speed idication jumped at the same time the needle did...

On the other hand, I've got a PC based OBDII scanner that you can have, if you've got a laptop that you can install the software on.

The VSS sends a signal to the ECU that tells the car how fast it's going.

I think the ECU sends a signal to the speedometer that indicates the speed of the vehcile.

I've noticed, for instance, that when running the diag comp the ECU reports the speed consistantly 2MPH slower than the speedometer indicates.

If the needle is jumping up and down, but you do not feel surging or fading in the car (caused by loss / gain of power)... then you've probably got a bad VSS.

The tachometer is known to have the same symptoms when the ICM (ignition control module AKA "ignitor") is dying in the distributor.

1) Swap the VSS with a known good one from any 5G Prelude (manual or automatic).

2) If it still does it with a known good VSS, swap the ECU.

3) If it still does it then.... then check the transmission in the area where the VSS connects. It's possible a gear or something is messed up in the mechanism that relates final drive rotation to the VSS module.

ludedood97 · 06-30-2004, 10:41 PM

thanks g :-D i got it all fixed, the recall on preludes for the ignition module fixed it all.

Gerhard · 07-01-2004, 07:36 AM

Quote:

Originally posted by ludedood97
thanks g :-D i got it all fixed, the recall on preludes for the ignition module fixed it all.

The ignition recall fixed your VSS issue?

That I've never heard of...

ludedood97 · 07-01-2004, 09:02 AM

well basically since the coil would heat up thats when the speedometere would start going crazy, so then when i let the car cool off it would start working ok again. Also i could i have my car in the on position but the electronics wouldn't be working, there was play in the ignition. 30 min fix for Honda, FREE too!!!