Ferm, I need Jeep help asap
 

96 jeep cherokee, ran fine yesterday, tried to start this morning, would not start, turns over, no power to coil, check asd relay, no ground to relay(blue yellow wire). Supplied ground to relay(jumper wire), have power to coil, still will not start. Fuel pump is not cycling. Hooked code reader to computer, not makeing contact, key is on, red indicator light on dash is on, no comunication to ecm from reader. What am I missing, is there a relay I don't know about that turns teh ecm on?

never mind, I figured it out, crank position sensor shorted to ground, low reference voltage, check engine light would not come on when key was turned to the on position. Checked for 5v on refernce line, had 1.2 volts, started unplugging sensors and checking voltage, when I got to the cps, I had 5 v on the reference line.

That's what I was going to say.

me too

Yea Right Randle and Phat youre probably like me and don't know what that thing IS!!!

If I had found this post sooner I could have saved you a little time as the CPS is tied into the main 5V reference line coming out of the PCM and it shorts out everything. If you test it by the book it will tell you to replace the PCM. Chrysler figured out there mistake a year or 2 later, but ALL 96 Chrysler products are plagued with this issue, and the crank sensor is the first one to fail normally.

i agree with both of the post above

I especially agree with this post.:hide:

Do what Ferm said....if not you can check the GFCI on the Flux Capacitor making sure it's top dead center on the re-entry differential.

Hey now, that is just plain wrong to go telling him stuff like that. Everybody knows they are now using arc fault's, GFCI'c went out years back.

you guys(except for Ferm) must be really bored, is the weather that bad where you're at? Ferm, thats teh first time I've ever seen a sensor fail to ground, Its in every trouble shooting guide I've used, but I've never seen it before. I called freind of mine and he got me on the right track, I had problems with the asd before, so I got hung up there. Thanks anyway.

I am not bored at all, matter of fact I kind a like having you guys around.:beer:

On the Chrysler products with a 3 wire crank sensor it is actually fairly common, and seems to be the only one that fails to ground and takes out the whole circuit. The earlier 95- SBEC controllers had 2 5 volt regulators in them and didn't seem to suffer this problem, but the later 95+ JTEC and SBEC's in the cars had the single regulator till around 2000 or so.

yes, the weather sucks &
once again,
i agree with ferm..
assuming you checked the dilithium crystals.

All right Scotty, beam Phat aboard before he gets lost and confused

if i had found this post yesterday i could have shortened your search as well been they fixed that on couple different Jeeps both were 4.0 motors on a 92 and other a 99.

thanks for all the input, I had it diagnosed before too long, everything was fine till I dropped one of the bolts for the cps in the flywheel housing, two hours later after fishing it out with a magnet and pulling the starter to have a place for it to come thru, i got it all done.

I was just going to point that out.. you're request for help was at 9:46 am and your "never mind" was at 10:56 am. throw in the time to get to and from the computer (twice) and probably pour a fresh cup of coffee and say you figured out pretty quick.


And you should have known the flux capacitor always shorts to ground.