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Ask -Brad- Your Own Question
-Brad-, Dodge Dealership Tech
Category: Dodge
Satisfied Customers: 7945
Experience:  16 Yrs Chrysler/Dodge Technician. ASE Master Certified(L-1)
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01 ram 2500 5.9l gas. have code p1391 crank or cam sensor. I

Customer Question

01 ram 2500 5.9l gas. have code p1391 for intermittent crank or cam sensor. I have replaced the following:
crank sensor
cam sensor with distributor
the truck runs like garbage, smoke coming out the exhaust. its blueish in color and smells like fuel. I cant start it unless I press the gas pedal and soon as I let off, it dies.
codes comes back on almost immediately after clearing it. also I noticed that the only thing on the dashboard that is working is the odometer. after a few seconds or working the throttle to keep it running the odo flashes a few times and "no bus" appears. the gauges are not responsive. trtuck is charging at almost 14v.
the old crank sensor was rubbing the fly wheel so I cleaned off all of the rust on the block, installed new one then ran the truck for a second. removed the sensor to make sure it wasn't rubbing and it is not.
Submitted: 1 year ago.
Category: Dodge
Expert:  -Brad- replied 1 year ago.

Good evening and welcome to JustAnswer!!!

Do you have a scantool? The No Bus is telling you that the Bus communication is down at the moment which means the different modules PCM, MIC, ABS, Etc can't communicate with each other because either a module has failed or you have a wiring issue.. If you had a scantool you could do a module scan and see which ones are responding and which ones aren't.. WIthout a scantool you will need to start disconnecting modules until the No Bus quits flashing and then replace that module..

The P1391 is a intermittent loss of crankshaft or camshaft sensor signal. Were the sensors OEM or aftermarket sensors that you replaced?

Customer: replied 1 year ago.

replaced the sensor from auto zone. duralast I believe. I do have a scan tool and I will try that now

Customer: replied 1 year ago.

I just tested the 5v wire at the tps sensor and its 3v. I have 12 at the battery. when I disconnect the crank or cam sensor the voltage does not change at the tps

Expert:  -Brad- replied 1 year ago.

3v is not good.. Start by disconnecting the cam-crank-map-tps and see if you get 5v back. If not then test for 5v coming out of PCM.. If still 3v then replace the PCM.