Kelly Hinchy
Junior Member
My 02 Ram is giving me a P1391 loss of cam crank code. I have replaced both cam and crank sensors. I have checked the wiring to the sensors and get a consistant 5.12 volts no matter how hard i shake or bend the wires, even at the connectors. I have cleaned all grounds and even replaced the alternator because it did not provide consistant voltage when under load. I have visually inspected all wiring harnesses and see no defect. I disconnected pcm, removed cover and inspected and saw no corrosion or burns. I cleaned mating surfaces and bolts and reinstalled pcm. Sooner or later after resetting it still gives me the P1391 code and starts dropping rpm around 2800 and then again around 3800. After i reset the codes truck runs like brand new for a bit then will do the rpm drop, throw the code then run worse. If i accelerate moderately it tends not to have the rpm drop, harder acceleration will cause the rpm drop. After checking the wires for the second time tonight i took it for a test drive, light was off and it ran great, so i stopped then gave it a hard acceleration start, i floored it, the truck took off and accelerated nicely but the headlights went out, then flickered back on, the back out then stayed on. Did not notice any rpm drop. Did it again and it did the exact same thing then engine light came on, and sure enough P1391 code. Timing chain was changed about 6 months ago, did remove right valve cover and inspected, chain was tight and everthing looked ok. I need my truck for work please help me if you can. Thank you.
