vt calais tacho problem

[LsCali]

I got a vt calais with a vz ls1. I just bought the car and on my first drive i realised that the tacho is showing a fraction of the actual rpm, at idle the needle is at 200 rpm. when i floor it its showing 2500 rpm before changing gears. Engine is running perfectly, everything else on the cluster works fine, no codes detected.

 

[EYY]

What engine should be in it? Is it a v6 cluster? (Not sure whether they're different to v8's for the vt's)

 

[Nut Kracker]

May be a miss match between the PCM, cluster and engine?
I dunno!!
In other words a "Cluster F###".

 

[LsCali]

The car was originally a v8 so its not an engine mismatch. from what i know everything is as it should be, only the engine has been changed. Maybe somebody has an example of a tacho input signal for different rpm, (frequency, voltage vs time) so i could eliminate the cluster or pcm. Also what inputs does the pcm use to calculate rpm?

 

[s_ikari2015]

guess what? you can twist the needle manually to adjust it. Yep, if it's consistently out for the full range then it has probably been taken off before (with a fork slid underneath and pull) and then put back on a little bit out.

Easy fix, kinda, if you don't mind taking the cluster out. It's pretty easy, just a little time consuming.

 

[LsCali]

Changing the tacho resolution in the pcm solved the problem with the rpm. Couldnt explain why until yesterday when I removed the cluster and turns out it was swapped.