How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Dodgerench Your Own Question
Dodgerench, ASE Certified Technician
Category: Dodge
Satisfied Customers: 3385
Experience:  30+ years Dodge/Chrysler exp., ASE Master with L1 certification. Driveability/ combustion specialist
Type Your Dodge Question Here...
Dodgerench is online now
A new question is answered every 9 seconds

what is intermittent loss of cmp or ckp mean

Customer Question

what is intermittent loss of cmp or ckp mean
Submitted: 7 years ago.
Category: Dodge
Expert:  Dodgerench replied 7 years ago.
Customer welcome to Just Answer!.


P1391? It's pretty much as described, wesley... it means the engine controller (PCM) has seen an instance where cam or crankshaft position signal has been lost momentarily but it can't decide which one it is. Cmp and ckp are shorthand for camshaft and crankshaft position sensors.


It may be that both disappear momentarily or only one does, but is too fleeting to be properly diagnosed by the on-board diagnostics.


I might be able to shed a bit more light on your problem if you'd send me information on the make, model, year and engine of your vehicle. If you're not sure about any of these items, sending me the last 8 digits of the VIN will allow me to access the build information in great detail.


Also let me know if there are any driveability problems associated with the P1391... stalling, bucking, surging, misfire... or just a MIL illumination.