2005 kenworth c15 acert in a 2006 western star - wont rev past 1500 rpms

Hey guys,

I have a huge problem and need to get back to work. I would appreciate advice from anyone. I have a 2006 western star and recently replaced my c15 acert mxs engine that blew up with a 2005 c15 acert bsx from a t2000 kenworth. Im still using the original western star ecm. The engine starts up, runs fine but will not rev past 1500 rpms. All the gauges work but the check engine light is on, we pulled the codes and the computer is saying that it is not recognizing the speed sensor. We changed the speed sensor, same problem. We noticed that the sensor locations are different on the replaced engine. We think that there may be an issue with the wiring harness or the ecm but we are not sure. Im in between new orleans and orlando. We contacted a few shops but nobody seems to know whats going on.

Thanks in advance for any help.

Uncle jack

 

There are two speed sensors? Do you think its a problem with the sensors, the ecm or the wiring harness?

 

I got the problem fixed guys. Here is what happened. After trying to get the problem fixed with a regular truck mechanic, i got nowhere and decided to take the truck to caterpillar. The first thing they told me, was that i had to reprogram my computer to match the bsx engine. That cost about $350. The computer was still giving a speed sensor error, even after we changed both speed sensors. After this, i took the truck for a test drive but noticed it still would not rev past 1500 rpm and there was no torque. I took it back to caterpillar and the mechanic started to disconnect each sensor to see if the computer registered an error code while the engine was running. When we disconnected the boost pressure sensor, we noticed that no error code was generated and we also noticed that the boost pressor sensor appeared to be damaged after we removed it. We replaced the boost pressure sensor and then we noticed that the speed sensor error cleared immediately and wa la! The truck reved up to rpm limit. Apparently the boost pressure sensor failure caused the speed sensor readings to make no sense to the computer, which generated the error code. Why didnt the computer also generate a boost pressure sensor error code? I have no idea. But the problem is solved. Nuff thanks to everyone who provided insight on this. Hopefully this can help someone else in the future.
Uncle jack