Hey guys, strange problem:

2002 camaro z28 6speed

I think the calibration of my speedometer somehow was reset. I currently have 4.10 gears in my car - the speedometer was previously accurate (post gear change) but has since reset and now runs to a 1/3 of my actual speed. This problem is very annoying and I would appreciate information on how to re-tune the speedo. Multiple mechanics have tried and failed to fix it.

 

per your post,the speedo was indicating correct mph after gear change and computer changed to correct for the 4.10s',then all of a sudden mph indication is 1/3 of what it should be ?
has the speed sensor on the tranny tailshaft been changed to check to see if it's the problem ?

 

yes the speed sensor on the tranny has been checked/changed, still same problem.

 

I would start by connecting an OBD scanner with a live readout and see if the PCM is seeing the proper speed to see whether it's the gauge or something on the computer side.

 

I have tried to swap the cluster out which did not resolve the issue, so I'm guessing it isn't a gauge issue and is more on the computer side.

I'd really appreciate anyone's input on this issue as I will be traveling overseas soon and need to have my car in a sell-able condition.

 

bump for help