needed volvo wg wiring diagam

I have a 1997 volvo wg64 that has some gremlins in it. It has a m11 and 740 allison in it. It wants to through a engine fault code that is related to a change in ground speed. When this happens the engine light comes on and the engine is derated. If you unplug the speedo signal generator there is no speedo but the truck won't throw any codes either and runs good. I replaced the speedo generator and it made no difference. So it must be a wiring issue but good luck tracing wires they are all black. I also wondered if its maybe a bad ground wire.

 

that would be awesome. we are located 2 hrs from nearest volvo dealer. I called them and they refused to email or fax anything to help a guy out, they wanted me to bring it in or buy a manual. Thanks.

 

Thank you to Pablo-UA for the info. I think we figured it out I took it to a local guy and put it on his computer we changed a parameter for the speedo and it seems to have solved the problem. Thanks again