edit: double post

 

Coil connector pin #2, the one you measured battery voltage on, is common to all three coils. Measure from there to each of the other three pins. Should be 0.7-0.9 ohms.
Resistance readings you stated from the CPS and CamPS to PCM plug are fine.

That high charging voltage + external regulator makes me wonder, particularly about how high your voltage shot up when the engine over-revved. I know the electronics has some safety margin and overvoltage protection, but that's meant for momentary overvoltage conditions, not sustained. I don't know what to tell you here.

 

Wow you are such an unlimited source of information haha
it read
pin1 0.8
pin3 0.8
pin4 0.7

Well I have an aftermarket stinger digital voltgauge mounted on the dash, and it never goes above 16.5 volts.
My regulator is a Transpo 911-02, From what I hear its pretty reliable in terms of keeping voltages in check.

But never know, I do admit I am almost positive I was having high amperage surges at first when I cranked up the stereo.
ABS light would come on, and eventually enough to eventually ruin my expensive heavy duty amplifier. (that was built for the power)
It ended up being a bad ground from the alternator to battery (I have since added many 0 gauge grounding wires)
But I also admit that still it was an amplifier that should of had more than one battery in the system.
Do you think this would of damaged my PCM?
The alternator maker Mechman Alternators, has previously told me they never encountered any issues. And they also tell me they work alot with wranglers, and other Jeeps with stereo and high output alternators.
But then again a sale is a sale

 

Also, where does the PCM ground on the chassis?

 

The PCM is grounded at the engine. The photo below is of a '99 PCM/Battery (-) ground point with the pre 2K ignition coil, but the 2000 - 2001 has the same ground point. The photo shows what circuits are grounded here.

 

This alternator system you have, putting out 16.5 volts, may have damaged the PCM. If you install a new PCM to rectify your no ignition problem, it may damage the new PCM as well.

 

Good stuff thanks!

I wonder what it could of done. Thinking this was a result of previous surging in the system.

Why would the new PCM get damaged? Because of the charging voltage?

 

[QUOTE=x91evo;2365988]Why would the new PCM get damaged? Because of the charging voltage?[/QUOTE]

Yes.

 

Alright that makes sense, Just wanted to hear it from someone elses exact words and not my ideals ha.
Adjustable regulator so I can turn it down, and probably will after this.

When looking over the car, I noticed my BTS(battery sensor) and CrankPS both had multiple open wires near the head of the sensors- that may of shorted.

Add to that my possible issue with the charging voltage, and intermittent starting.

 

So I am guessing, I should go ahead and point my attention towards another PCM right about now?

Just seems strange that after 1 1/2 years of charging @16.5V it decided to go now?

 

Well I got a great bit of info from naxja...

Not sure what I did wrong but alright.
Hopefully the cherokeeforum gurus can chime in sooner than later

 

CCKen is one of the sharpest guys here with the engine management stuff. If he thinks your PCM might be damaged, I can't think of any logical reason to disagree. Of course there is always a certain amount of guessing and assuming when you can't see the vehicle.
You've replaced the Cam PS and CPS, verified the wiring, verified ASD operation and have power to the coils, there isn't a whole lot left.
I assume you've already replaced the coil rail as you have a spare to compare measurements?

 

This is true^
And yes I have
Just getting really close with money and needed to be sure.
Didnt mean to doubt anyones diagnois!

I will report back when I find a PCM to swap

 

I really don't know what to tell you other than your aftermarket alternator/voltage regulator system may be the root cause of your problems. The voltage regulation should have been set at around 1.5 volts above the normal battery open-circuit voltage of 12.4 volts-12.6 volts. The maximum off-vehicle battery charging voltage is 16.0 volts for up to 4 hours and you were running 16.5 volts continuous while operating your vehicle. If you had adjusted your onboard voltage regulator to around 13.8 you may not have had electrical system problems. As you can see, 16.5 volts may have damaged your battery.

The OEM charging system, controlled by the PCM, would have taken care of the battery charging rate and continuous bus voltge. It would have seen the state of charge of your battery at start-up and provided the appropriate charging voltage until the battery stabilized at, what the PCM considered, an acceptable charging rate and bus voltage of around 13.8 (+/-) volts.

I have no idea how your aftermarket charging system works concerning interface with the PCM, but I would suspect there is an interface somehow. I'm surprized you didn't get a P1594 CEL.

~~~~~~~~

You asked: "Just seems strange that after 1 1/2 years of charging @16.5V it decided to go now?"

I have no idea why it would take that long but I have to ask - How long did it take running at 16.5 volts before it blew up your boom box amplifier?

~~~~~~~~

Before buying a new PCM I recommend that you send your PCM to a shop that rebuilds PCM's and have them check all internal functions.

While the PCM is in the shop, have your battery bench checked.

Adjust your voltage regulator down to 13.8 volts once you get your vehicle running again.

 

Funny you say this because I have had other jeep people gawk, when I tell them my charging voltage

Im using a 14 volt battery

I wonder if there anyway I would be able to modify what it sees as acceptable? I know these PCMs are rom, which I thought was easily re-writeable?

Never got that code before! Only thing that was clear to me was a "check gauges" light on the dash. Also my voltage gauge on the dash would stay at 19V, and it had become obvious it wasnt sufficent for anything above 14V
Yup that seems like a clear problem to me from the beginning, it doesnt interface with the PCM at all. Its a standalone system that simply ups the Amperage, and allows the user to adjust voltage.
Mechman Alternators actually had advised me that the PCM would be alright at that voltage.

~~~~~~~~
Honestly I feel llike an idiot and should of known better.
It was approx 6-8 months of seeing surge almost everyday.
(stupid me)
There was no problems at idle. But when the RPM would get above idle if I had the stereo past a certin volume level, the amplifier would reset and continue to reset until the RPM would drop. Which is what I eventually realized, that seemed to be a surge.
But the amplifier had finally quit on me because of problems not recieving enough amperage for the power level I had adjusted it to on the unit.
(Again stupid me)
Which makes me wonder if that was a major player in this problem I am having now?

~~~~~~~~

I think I will not go above this voltage again. Thanks for all the helpful information

If anybody else is reading this in the future, consider reading this thread on Cnet. Although this thread was for a grand cherokee, It explains how the PCM would short itself through the case of the PCM itself. Which I am going to look into right after I post this lol
http://forums.cnet.com/7723-7811_102...talling-fixed/