Katmandu

Not yet fixed but getting closer. Just don't have the time to work on it.

Anyways, I checked out the Crank Position Sensor and it "appears" to be the culprit in this mess.

I unplugged the CPS (at the connector), then turned the key to the ON position. The gauges then came back to LIFE !!!

I also did verify that it is in fact receiving the 5-volt signal from the PCM.

Next, I started the truck (CPS still unplugged) and noticed the alternator seemed to be not charging. So I went and pulled it out and took it to be bench tested.

The alternator bench tested out GOOD. Diodes are good as well.

So, I ordered a new CPS. Will be here tomorrow AM.

BTW, I did pick up another PCM just in case mine turns out to be bad after all.

vzdude

I would say you are on the right track! Like I said before, I very well may be wrong! It is possible for the crank position sensor to be shorted internally. Haven't seen that happen before, but there is a first for everything! Good luck, and keep me/us up to date!

Katmandu

Yea, it is somewhat confusing. Everything I've studied/read up to now says a bad CPS would NOT effect ALL the gauges. So that "MAY" not be the case after all.

Is there a way to check out the CPS OFF the vehicle ?

I'm going to "try" and dissect the old one to see if I can see anything obvios. Either that or I'm getting my hammer out and smash it!

vzdude

A couple of things.......try checking the continuity of the wires from the cps to the pcm. If one of the other wires is shorted to ground or shorted to the 5v reference signal, it could be throwing the pcm for a loop!

Katmandu

Very good point vzdude.

Gonna be difficult to accomplish. Going into the single digits tomorrow....I can't fit my truck inside my garage.

Gonna give it hell though.

Katmandu

A bit more progess made this AM.

I just picked up the new CPS and plugged it in to the harness. Turned the key ON and the gauges came ALIVE!

Now I just need TIME (and the temperture to go back above 20 degrees) to install it and my serpentine belt and hope it ALL works out!

It SUCKS not having a garage to work out of.

BTW, my wife gave me an earful this AM saying she wants me to sell my truck and get something NEWER.

Should I get rid of her or the truck ?

vzdude

There's no descision in my mind! LOL Gotta say though......that is the first time I've heard of the cps locking up the pcm bus! Wierd!

Katmandu

Guess I need to start wife shopping!

Anyways, I'd really like to know WHY the CPS caused all this havoc!

I don't have it all together yet, so keep your fingers crossed!

XLR8R

"I'm sure gonna miss that girl!"

Dave Miller

How about get her a new truck and keep the old one. Otherwise you got no choice...don't mess with a mans truck.

patdaly

I did that exactly ONE time.

She knows she will never get a second shot at it.

Remember the good word, "Our Cummins, which art inline....."

sweeney186

[QUOTE=Katmandu;1908004] Guess I need to start wife shopping!

Anyways, I'd really like to know WHY the CPS caused all this havoc!

Chrysler pcm's since 96-gas & diesel have internal protection for 8v/5v feed to cam,crank,veh speed sensor(due to speed of input)-a short in those circuits triggers the pcm shutdown-its either that of let the smoke out of a $600 controller.The pcm provides "bus" communication voltage in none "can" vehicles.

Katmandu

Ok so, technically, my PCM "should" be still GOOD then correct ??

I'll find out (I guess) after I install the new CPS.

Only (14) degrees here so it's gonna wait another day or two until it warms up here.

sweeney186

Yes it should

Dave Miller

YES...technically! When I replaced my PCM and it didn't fix my problem I put the old PCM in and replaced the CPS which I then determined was bad. THe old PCM worked fine and is still running a year later. I got a spare PCM now. I did the same thing you did...put the new CPS in and got my gage lights back with key on. Then when I started the truck everything worked. I proved the 5 VDC to CPS from PCM was shorted....0 vdc with bad CPS connected to PCM but it did not harm my PCM.

Hopefully you won't need a PCM