Engine/Transmission (1998.5 - 2002) PCM Price

[DLBurns]

Anyone know what the going rate is for a new PCM??

 

[DLBurns]

In the 5 years I have been a member here, I don't recall seeing any posts about bad PCM's... am I mistaken and my old age and senility have finally done me in?

IF anyone has replaced theres, I would be interested in what the symptoms were that necesitated the replacement of the PCM?

O yeah... and a price on a new one? Anyone??

 

[Wiredawg]

I haven't ever seen anyone post w/ a bad PCM... you may want to call your Five-Star to get a price.



Let us know the price,



Good Luck, Wiredawg

 

[CDrake]

I just happen to know that price. Took my truck to the dealer for TCC locking and unlocking in May 2003. Dealer gave me the price for replacing the APPS and PCM of :{ $1515. 00 :{



Told him not to touch anything, i'll be right there to get her. All the way to the dealer i'm thinking "thats it, i'm trading her in for a 6 speed" picked the truck up and i'll be d@mned if that TCC never so much as hiccuped till last week.



Makes me wonder if the tech just disconnected the batteries and reset the APPS

 

[Trashdawg]

I think depending on year a star part ECM is around $1000 and a Reconditioned one is $600 for the older 24v

 

[Marco]

Actually, Ive seen many more failures on the PCM than with the ECM.

In the 911 archieve there's a thread where I helped a guy in Guam to diagnose and FIX his PCM.



Most times the PCM has problems with the alternator field and the OD solenoid . That means, if both quit working first look at the PCM.



I don't know the price for a new one. Sure enough the uprate PCM's for the gasser engines were rather cheap. About 300 bucks if I remember correctly.

Gasser and diesel PCM's are almost the same unit...



Marco

 

[RBallard]

I checked on this when the MAD Catcher came about. I found quite a few yards that offer flashed PCM's for your application for around $300. PM me if anyone needs the more details, I have the info stashed somewhere.



Bob

 

[JBlock]

I pick one on ebay for under $100 thinking it was an ECM, it in a box now.

 

[DLBurns]

I am going to swap out my PCM this weekend and see if that cure my problem, if it does I will be in the market for a new PCM, if not... . then its back to the drawing board.

Aren't there any electrical geniuses out there who can help diagnose this problem?

 

[Marco]

WHAT is your problem?



Marco

 

[willyslover]

Marco. . he has a condition that wierd. . as soon as he turns on the air conditioner he gets a stumble/miss they disconnected the compressor and batteries [I believe] and did the same with no issues, however reconnecting the air conditioning comressor and turning it on same thing happens miss/stumble

I'm answering a lil bit for him as you on line and he must be still in bed



He and Blair Pine are working to resolve. . they have looked at the grounds and plugs so far [as far as I know for phone conversations with Blair]

 

[Marco]

Oh, wow, that's a new one for me... .

The PCM sends a MSG to the ECM when it engages the AC compressor in order to increase the engine RPM. That would mean... Hmmm could be the PCM but also the ECM. I've yet to see such a problem caused by the ECM.



TCC and charge circuits do work?



Marco

 

[DLBurns]

Marco,

Thanks for chiming in for me Gary, I'll try to explain my situation.

I had the APPS codes P-0122 and P-0123, tried disconnecting the batteries and then re-setting the APPS but the codes kept coming back. Finally just bought a new APPS. All was well on a trip we took up to Gary's neck of the woods when I switched on my defroster it immediately illuminated the CEL and set the codes for the APPS and I would get the engine stumble???

We have since disconnected every connection I could find and cleaned them with contact cleaner and re greased them with di-electric grease, we have done the same to the grounds ( those I know of and could find anyway ) On our last test drive we had the truck hooked up to a Snap On MT2500 scanner and had cleared all of the codes ( oh yeah, lost cruise control when the codes were present! no dash light for cruise , no nothing! ) With no CEL illuminated I had cruise control, the minute I switched the selector switch to AC the CEL came on and the engine stumble occured. As long as the codes were present I would get an intermittent engine stumble, especially above 10 pounds of boost?? we disconnected the AC compressor, cleared the codes and drove the truck again. No problem until I switched on the AC, CEL lights up and I get the stumble and lose cruise function. The engine would stumble every time the computer called for the ac compressor to cycle even though it was disconnected, and the volts on the APPS would go from normal operating range to wide open at 4. 96 volts then back to normal until the ac compressor was to cycle again???

I am really lost at this point. We are going to try and swap out the PCM with another one this weekend and see if that cures the problem... if not, it's back to the drawing board.

I know you are very familiar with the PCM & ECM's, if you have any ideas I would really appreciate them.

Thanks Marco

Dave

 

[Marco]

Buff,

that's a strange one! Let me explain. I can see evrything you're saying about the CC,AC, Cel. All those are PCM related and make sense in some way. What's really odd is the APPS voltage going all over ther place. The APPS is an ECM only item. It's in NO way controlled by the PCM.



Anyway, it could very well be that the fault is within the PCM. There must be a transistor in the PCM that provides the power to the AC clutch. Since you say that the problem also happens with the AC clutch disconnected, it HAS to be the PCM that's causing troubles. If the AC clutch transistor is shorted, could be that it cause all your troubles...



If you have some time read this thread about another PCM problem:

https://www.turbodieselregister.com/forums/showthread.php?t=116732



Let me know...



Marco

 

[Tcolesanti]

I had to buy a new PCM for my six speed truck, it cost right at $500 new. They gave me my old one back, I have been meaning to pull it apart and take a look at it.

 

[DLBurns]

Marco,

If the APPS is ECM only why do you think I am getting APPS codes when the AC compressor cycles? Another thing that Blair just reminded me of was that on the scanner we were in the transmission section of it reading the voltage on the APPS not the engine section, isn't the trans controlled through the PCM? And how is the cruise control controlled? through the PCM or ECM?

As far as the PCM, we are desperate to find a compatable PCM to swap out with mine and see if I still have the problem, if not then I KNOW it's the PCM. At that point I can take my PCM apart and see whats going on in there ( that link to the other thread was very helpful ) What should I be looking for, do you know off hand where the transistor to the AC clutch is locate on the PCM? How about a schematic showing the internal wiring of the PCM?

I can't tell you how much I appreciate your help with this.

Thanks a million

Dave

 

[DLBurns]

I had to buy a new PCM for my six speed truck, it cost right at $500 new. They gave me my old one back, I have been meaning to pull it apart and take a look at it.

I am in hopes that I won't have to replace my PCM, but if I do, $500 is better than some of the other prices I have seen for a new PCM. Who did you purchase yours from?

Thanks

Dave

 

[Marco]

To make it as simple as possible. The ECM deals basically only with the engine and it's sensors. All the rest it managed by the PCM. Then there is a data link between the ECM and PCM where they exchange informations. OK?



The transmission, AC, CC, Charge field for the alternator, the dash just to mention a few that come to mind are all directly powered and controlled by the PCM.



That's why I say it's confusing that also the APPS is off since it's a ECM only sensor. Now you say that you were monitoring the APPS THROUGH the PCM. That makes sense! Bingo, all the problems you have are now directly related to the PCM. See what I mean?



Anyway, before you try to buy a new PCM, open it. Maybe it's something really simple like the one in that other thread. Sorry I don't have any schematics about the internals of the PCM. They simply do not exist...

I've never seen this problem ( AC clutch ) before so I don't know where the "AC clutch transistor" is located. Off my mind... I think that almost all power transistors are located in the centre of the PCM.



Marco

 

[DLBurns]

Once I get another PCM to swap with mine and verify that it is indeed the PCM causing the problem I will pry it open and see what if anything is wrong in there. At that point I will have to buy a new PCM either way unless I can fix this one.

Thanks for your Help Marco

Dave

 

[Tcolesanti]

I got my PCM from Crown dodge. I was in a bind and needed one asap, otherwise I would have looked for one in a junkyard.