Tranny rebuilt now this
 

Two weeks ago I had my tranny rebuilt by a well known guy, 3 clutch converter all new billet parts ect. He also installed pillar gauges on my truck, everything seemed fine..couple days ago I opened my hood to check things out & noticed one of my batteries lost the cap on top of the battery thinking it was bad I took it back to the place & had it exchange under warranty battery was very hot so we checked out the alternator putting out 18.5 volts "over charging" so I replaced the alternator checked it again now over 19 volts. PCM bad ??? could this have happened when tranny was rebuilt or when the gauges installed :scare2:

Nope, most likely not. Sounds like a bad PCM. There's a very small possibility a wire could be shorted on a trans harness and fry the pcm but their would be no way to prove that without a damaged connector, trans not functioning correctly. Sound like you've just had some bad luck!

Did I miss something, I am new to dodges, or anything run by a computer for that mater. So... since when does the PCM/ecm or any cm have anything to do with alternator output voltage? I know GM Alts have built in Voltage regulators, and that older cummins powered dodges have an external VR, but as far as I know they are independant of the computers. Tell me if Im wrong.:humm:

every dodge pickup from 94 up (that I know of, Not big on 1st gens) is externally regulated by the PCM, and the important piece in this puzzle is the fact the PCM is also the TCM lol For instance if your 01 or 07 for that matter starts shifting funny, or starts charging unusually you could most likely clean the grounds on the PCM and fix the problem.

OK ill bite....whats a TCM?

Transmission control module, in dodges also known as the powertrain control module

Transmission cm ok i figured it out.

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Your making that 12v engine in my shop look better and better.

As I said before anything 94 and newer is externally through the PCM.

or a P-Pumped 24 valve conversion.

Failures I guess you could say are not all that common. I guess they seem more common to me for the simple fact we work on these trucks day in and day out and run across it more often lol

Not the PCM, that the power train controller.

The 92 thru early 98 trucks regulated the charging system thru the engine controller. That name varies a little but for the most part its referred to as an SBEC, single board engine controller.

When the 98.5 trucks came out then we got an ECM, engine control module that take scare of the charging system. The 3rd gens changed that a bit to ECU, engine control unit. Same thing really.

The PCM's were there for the RE trans controls, manual trans and t-case functions. An auto truck had a program called a TCM loaded into the PCM to control the trans. MY04 moved that function to the ECU and the PCM functions also and the stand alone PCM was gone. The 07.5 trucks brought back the PCM as primarily the TCM to run the 68RFE.

Now to the battery overcharging, start cleaning posts and connections. 99% of this type of problem is dirty battery connections.

Not to hurt your feelings but your wrong :)
Your correct as far as the 92-97 trucks...sorta, but as far as a part name at a local parts store it's a PCM, used the term to simplify the looking for parts.
As you'll see the in the following information directly from the manual
DESCRIPTION 98.5*2002
The Electronic Voltage Regulator (EVR) is not a separate component. It is actually a voltage regulating circuit located within the Powertrain Control Module (PCM). The EVR is not serviced separately. If replacement is necessary, the PCM must be replaced.

OPERATION
The amount of DC current produced by the generator is controlled by EVR circuitry contained within the PCM. This circuitry is connected in series with the generators second rotor field terminal and its ground.

Voltage is regulated by cycling the ground path to control the strength of the rotor magnetic field. The EVR circuitry monitors system line voltage and battery temperature (refer to Battery Temperature Sensor for more information). It then compensates and regulates generator current output accordingly. Also refer to Charging System Operation for additional information.

Now I can understand why you might think ECM because the terminology in some books was funny like that. The pcm is firewall mounted passenger side, the ecm is block mounted.

Here's the 94-97 operation description
CIRCUIT OPERATION
The charging system is an integral part of the battery and starting systems. Because all these systems work in conjunction, diagnose and test them together.

Circuit A0 from the battery connects to a bus bar in the Power Distribution Center (PDC) . Circuit A11 connects to the PDC bus bar and the output terminal of the generator. A fuse in the PDC between A0 and A11 circuits protects the charging system. Circuit Z1 provides ground for the generator.

On the diesel engine applications an additional battery is used. Circuit A0 connects between the battery positive terminals of the batteries.

When the ignition switch is in either the START or RUN positions, it connects battery voltage from circuit A1 to the A21 circuit. Circuit A21 powers circuit F18 through fuse 9 in the fuse block. Circuit F18 connects to the coil side of the Automatic Shut Down (ASD) relay. Circuit A1 originates in the PDC and is connected to battery voltage. A 40 Amp fuse in cavity 3 of the PDC protects the A1 circuit.

When the ASD relay energizes, it connects circuit A16 from the PDC to circuit A142. Circuit A142 splices to connect to the generator connector supplying battery voltage to the generator field.

The Powertrain Control Module (PCM) has an internal voltage regulator that controls generator output. Circuit K20 connects the generator and PCM, cavity B1O. The PCM controls the generator field on the K20 circuit.

When the engine operates and there is current in the generator field, the generator produces a B+ voltage. The generator supplies B+ voltage to the battery through the A11 and A0 circuits.

You are however correct on 03 and up trucks, but the terminology here is also a bit off.
Not trying to be a smart A$$, Just trying to make sure you have a clear understanding of how the systems work. As you'll see I've included images to show how the systems were routed, and I'll be glad to include more if needed.
Again, you were correct on 90+ trucks, just incorrect terminology. If need be I can always take my proof a step further and pull the Powertrain diagnostic manual from the shelf and scan it for ya.

I will add I thought we were talking 99 I didnt realize we were talking 04.5. I must have been looking at something else lol

Either way still good info!:rocking:

Relying on that as a basis will get you the wrong info as will relying on a lot of the documentation. The proof readers don't have a clue and even the FSM's have glaring terminology errors or just plain missing descriptions.

Going by the Cummins terminology they know what an ECM is for a Dodge truck providing you have the CPL. They don't know what a PCM is for the truck. Part of the confusion comes from the use of the JTEC controller and exactly what it did in the diesel applications. Just becuase its capable doesn't mean it was used that way.

PCM and ECM is transparent in a lot of documentation becuase it was not specific to the truck. In other words they copied it without regard of the actual configuration. The 99 I traced out routed the alternator controls back to the ECM. Thats what I am basing my info no matter what the documentation says.

As for the OP's question the charging controls are definitely in the ECU as are the trans controls and all the power train functions. So the ECU now has the PCM and TCM integrated. Dispute the acronyms all you want but those are how the technical documents describe the pieces and functions.

I am not trying be an ass either. I can only report on what I can see with my eyes. :)

I can assure you the comment in bold is not the case. lol no offense. Why would I know this? I order them from dodge and aftermarket sources all the time, without issue. Now with that said, We dont order anything but hard parts from cummins. I'll say it again, 94-2002 the only wires in the charging system run directly to the PCM mounted on the firewall of the truck, I'll even pull the wires and take pics if you like. On top of that, You could replace ecm ( the actual one below the VP lol) and not fix a charging issue....dont ask me how I know.



I think the best way to prove my point is a simple picture detailing connector pin out. All the proof I need is in the fact the ECM has one plug, and the PCM has three, Below are the connector pin out views showing in plain detail where the wiring terminates at. As you'll see the wiring for charging all terminates at the PCM which controls the voltage. Now I'm not sure if your trying to say the PCM is called a "ECU" or "ECM" by cummins or if your saying the ECM actually (the one below the pump) controls charging.
Now you stated in your post that the wiring you had checked terminated at the ECM on a 99. The diagrams below & my personal experience say otherwise.
The terminology for all dodge tech and most ASE certified tech would tell us the PCM is what we would order if our voltage regulation stopped operating properly.

Here's some additional documentation proving my point. So obviously, you either traced a 1 in a million truck that was setup that way or your wrong.....just admit it lol

just pickin buddy but I am correct, anyone else want to go look at their truck, and unhook pin 10 and 11 out of C2 on the PCM and see if their truck charges? Or better yet, ohm out the wires and see if their connected to the alternator lol

Just verified, cummins does not offer a pcm, its a dodge only part and cummins had no part in the design or operation of the charging system. That's per a 25 year cummins tech

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The edit button was gone, Or i would have edited my post together and posted a little note.
I know this seems like a heated debate on my end and I'm sorry if it seems I'm pushy, Not trying to be but all to often there is no actual debate on diesel forums. I'm trying to show my side, and why I feel the way I do, Same as cerberus. The goal is not to make enemies, but create debate and learn from the experience. If we all just sit around and say right wrong indifferent than we've not accomplished much. But if we have technical debates where each party shows their thoughts, not just the parties involved can learn but everyone with less technical experience can learn from the debate. All to often conversations like this are stopped before anyone learns anything (I admit, I'm a bit of a forum Nazi lol ).

Again, Cerberus this is all in good fun, and I've enjoyed our conversation / debate

As far as I know, the voltage regulator is inside the PCM on Dodges.

:pca1:
Loose battery connections that was it :argh::argh::argh::argh::argh:

I agree, discussion without differences isn't. If not for different opinions we all would still believe Ford owns Cummins. :scare2:

I am running from memory the wires wire that triggered charge is in the ECM connector and it traced that way. However, lots of pins and its possible the guy at the connector read the pin wrong, or, possibly the relay is in the PCM and it is triggered by the ECM, or the harness was shorted.

Five years and lots of times tracing wires could produce erroneous memories. :w2: Either that or I am getting old. :argh:

ok im gonna sound like the dumbass here! my 07 is charging funny and the tranny is starting to feel funny so where would the grounds for the tcm be located? one more question while im here. i recently went to a bigger rim and tire 35-12.50-20 been on for about a month and now there is a phontom vibration had the itres rotated and balanced twice been on the alighnment rack twice and have checked over everything with the truck on the ground and jacked up and cant find anything!!:argh: its driving me absolutly crazy from 60 to 70. please help thanks!

You don't have a seperate TCM, its in the ECU. Check all your grounds for the battery, the connections to the batteries themselves, have your batteries tested.

The vibration could be the typical drive shaft angle problem if you have a 2 piece shaft, or, a bad u-joint.

not a two piece but was goin to the ujoints next. thanks!!!!

make sure all you lug nuts are there and tight , not x-threaded. had some tires that I bought online mounted by the local tire shop, and they ran all the nuts on with the impact, an x-threaded one.
Prior to that though on another vehicle, I experienced a phantom vibration at 70mph on the interstate. so I slowed down, and it went away, then I sped back up. Then the back of the truck droped, and I looked in the rearview mirror in time to see my right rear tire and wheel bounceing all the way across two north bound lanes the median, and all the way across both south bound lanes, and into the ditch. Fortunatly no one was close enough to even concern them. I can only conclude that the lug nuts were loose. Three of the five were sheered of, and asside from destroying the aluminum rim there was no other dammage.

Can you feel the vibration in the steering wheel, which might point to a front end problem like ball joints, or wheel berrings
If you cant feel it in the steering, then then universal joints. In my experience they will cause a vibration so you cant even see out of the rearview mirror. I have had them come appart with little or no warnning though.

Im no mechanic though, just 25 years of driving and wrenching on my own used vehicles.:w2: