Detail: I have a problem with my speedometer not functioning right. I think it started when i drove through a bunch of puddles. The speedometer starts off not working at all. After driving a while it starts to fluctuate a lot and sometimes after 10 miles or so it starts working again. I just replaced the PCM speed sensor and i'm still having the same problems. I'm going to check the wiring tonight but if someone has a better idea or a solution that would be greatly appreciated.
Solution: There should be a speed sensor in the transmission for the speedometer and the engine computer. There is a sensor in the rear end for the ABS. Are you sure you replaced the right sensor ? , Hi, a 6ya Mechanic can help you resolve that issue over the phone in a minute or two. Best thing about this new service is that you are never placed on hold and get to talk to real repair professionals here in the US. click here to Talk to a Mechanic (only for users in the US for now) and get all the help you need. Goodluck! , Its most likely either or, if its a high pitched sound its probably the wheel bearing. If its a growling/grinding/clunking sound its probably the CV Joint. However, your problem more than likely lies in either/both. , Actually the Speedo is controlled by the PCM I would pull the NEGATIVE battery cable for 30 minutes and then hook it back up. this will reset the PCM. , Sounds like your clutch is not releasing enough to allow you to engage or disengage. It is dragging which causes hard engagement and disengagement. Possible causes are, Low fluid in the master cylinder to the clutch, or bad slave cylinder down by the bell housing, or badly worn pressure plate, or air in the line leading to the slave cylinder. You will need to eliminate these items one by one by testing to find the bad item in the system. Good luck , Fuel filter? There's also a filter on the suction intake inside the gas tank, it can get plugged up. I'd definitely try the filter if you haven't. Good luck. Have you checked the fuel psi coming from the tank? If it's fuel injection, it should be pretty high, 55 - 60 psi. Let me know if I can help. , check and see if there are any recalls on this. I have a 2004 Avalanche that this happened to me on and it turned out there was a recall on the instrument panel and it had to be replaced to fix the problem.