1999 Dodge Ram 1500 5.9L started then immediately died. Now it will turn over but wont start. Couldn't hear the fuel pump start up with ignition on so took it as bad fuel pump. Removed bed replaced fuel pump($200) put bed back on still has same issue. Started looking online and seen something about no bus so went out and checked sure enough no bus is the odometer. I ran odometer diag and gave me 920, 921, 999 error codes which from what I understand is that cluster is not receiving distance pulse and speed pulse messages from pcm. I looked even more and tried unplugging crank, cam, abs, and a few other sensors one at time to check if error would go away nothing worked. Next thing I found was to replace pcm. I ordered pcm got it in today and installed. Truck is still doing same exact thing. Any ideas I have ran out of options and have already spent over $500 in parts and tools to no results.

 

Check the O2 sensors as well. Basically, any sensor on the 5 volt bus. (including the trans.....) Can you plug in a scanner, and communicate with the PCM? Do any of the gauges work with the key on the on position?