Random Codes

skatermike21988 · #1 05-26-2007, 06:47 PM

Ok, I am having trouble starting my 93 3.9l, i pull the codes and it returns 12, 14, 55, so i check them, go back to the truck reset the comp, and i get new different codes, 12, 33,55 then i go again, i get 12, 33, 54, 55 and again i get 12, 24, 55. I dunno what it is, i think maybe my pcm is bad and it's throwing out codes left and right. The truck wants to fire up but is not getting it's continuos spark, any ideas?

dodgerules86 · #2 05-27-2007, 07:50 PM

12 and 55, of course, are normal codes to have.
14 (MAP sensor)24 (TPS sensor), 54 (CAM sensor), I believe, all have one thing in common: they get a 5V input from the PCM. (Also, without proper inputs from the camshaft/crankshaft sensors, the truck will not start up).
Make sure the connector for the PCM is clean and corrosion free.
Inspect the connectors at each of those sensors for the same. If that finds nothing, I would suspect it would be time to inspect the wiring.

skatermike21988 · #3 05-28-2007, 07:12 PM

ok, i have checked the pcm for corosion, none there, i haven't checked those sensors, but i opened up the pcm and the rubber seal in it is all cracking, is that normal?

dodgerules86 · #4 06-01-2007, 11:06 PM

hey, sorry for the delay response.
you opened up the pcm? hmm.. you didnt have to do that, but no harm done i guess.
as for the rubber seal, i would think its normal, 14 years can be hard on stuff like that.
right now, i cant really provide you with more technical information, since i'm half-a-world away from all my information, but im willing to bet its a problem related to one of those sensors.

skatermike21988 · #5 06-09-2007, 05:03 AM

ok, when the key is in the on-but not start position the pcm makes a verry high pitched humming noise, is that normal?

dodgerules86 · #6 06-09-2007, 08:06 PM

I would have to say no.

skatermike21988 · #7 06-13-2007, 06:14 PM

ok, i'm ordering a new ecm for it, i didn't think that it humming was normal either.

skatermike21988 · #8 06-22-2007, 04:19 PM

well, put in new ecm, no luck, i'm officially lost, is their anything in the tranny that is part of the ignition electrical circuit. it ran b4 new tranny, but i don't know, i'm not getting any codes besides the normal 12 and 55, any ideas?

skatermike21988 · #9 06-22-2007, 10:07 PM

haynes manual says there is a 20 amp fuse in the ignition circuit, i can't find a 20 amp fuse in my fuse box that has to do w/ ignition, and there is no 20 amp in my pdc, any idea where it's located?

[IMG]local://upfiles/55222/5A2E6C7F970A443EB0EB62C52DAE5C77.jpg[/IMG]

skatermike21988 · #10 06-30-2007, 09:02 PM

bump, any ideas?