So I have a 2001 Dodge Ram 1500 and I'm having some problems, I have pulled my transmission out twice and put it back in and never had a problem, on this third time I fixed it and put the transmission in, all the wires are plugged in correctly and none of them are pinched including the crankshaft sensor. Any ways everything is torqued to spec and in correctly but for some reason when I go to start it, it turns on and it's will fire up and run for 5 seconds and then stop and then just crank. Then my abs, airbag, brake, and check gauge lights all come on and all my gauges stay at zero and I know that I have a full tank of gas. After the lights come on my odometer will blink 3 to 4 times and then say "no bus". I have spent 3 hours looking this up and unplugging the PCM and crankshaft sensor and resting them by unplugging and then turning key till the truck turns on and then after 10 seconds turning it of and plugging it back in and nothing has helped, besides if I do that to the crankshaft solenoid my fule gauge will work and then it only lights up the abs and brake on my dash and it will keep how many miles on my odometer. I have also tried to run a scan from tool to it but it doesn't put any codes. I have no clue what to do or where to look and I really really need some help!

 

No bus means the cluster is not getting info from the PCM. Trouble is, it isn't a direct link.... On your truck, there is a 'central timer module', that acts like a hub on a computer network. (and that is basically what it actually is.) PCM sends info to the CTM, and the CTM sends it on to wherever else it needs to go.

First thing you need to do is, verify all the connections at the pcm are clean, and tight. This includes any grounds.....

See if that doesn't help.

Welcome to DF!

 

I have made sure that the PCM connection is in tight and that both the male and female end are clean and none of the cords or loose or anything and it is still having the "no bus" problem

 

Start unplugging sensors..... With key off, unplug crank sensor, turn key on, see if you get a mileage display. If it is still no-bus, turn key off, disconnect cam sensor. Keep going with every sensor on the motor, and see if you ever get a display. If unplugging one of the sensors wakes it back up, replace the sensor. If you get everything unplugged, and still get no bus, then either PCM, or CTM has failed.

 

You should sticky this post. Seems like a very good beginning point for a lot of things.

 

I unplug the crankshaft sensor and turn key to on and my fuel gauge comes back and says how much fuel I have but my abs, brake and check gauge light stays on and my odometer comes back and doesn't say no bus but my truck still won't start

 

Of course not. The crank sensor is unplugged. The PCM has no idea the engine is even turning.

Replace the crank sensor. Get one from the Dealer. The aftermarket parts don't always work all that well.

 

I replaced the crankshaft sensor and it starts up and was running, it still said no bus and my abs and brake light was still on but when I backed it up about 20 feet it all went away and it was fine, then I put it in drive drove another 20 feet and then it shut off and zeroed all my gauges out and then would only crank and not start again.

 

Check the wiring for the crank sensor. Make sure nothing got pinched anywhere.

Does the dash come back to life if you unplug the new sensor?

 

Only the fuel gage comes back and then it only says my abs and brake light stay on