Chevrolet cruze speedometer strange problem

[rsilva]

Hello all

I have a Chevrolet Cruze diesel from 2011 and speedometer needle moves slower than real vehicle speed. It moves like dash was in miles not Km.
With another dashboard, although not showing km numbers but the speedometer needle moves the same way.
Doing diagnostic to other ecus, in abs read speed vehicle correctly because it is done by wheels speed, but in engine ecu reads the same as dash because the speed is read by speed sensor in gearbox.

So, the speed sensor in gearbox connect directly to engine ecu. I can see that this ecu was openend for some reason. Maybe dpf or tuning programming. My question is:
Does reflashing engine ecu has interference with speed sensor counting? I already tested another sensor and dash and it stills the same.
How can i change ecu programming?

best regards

[berperez2003]

Hello
Have you checked the gearbox?

[rsilva]

Hi,

thanks for the reply,

And yes, already changed gearbox sensor and is the same thing.
I think problem is somehow in engine ecu coding because with another dash and gearbox sensor is the same.

best regards