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Discussion Starter #21
Sorry about that.. I was sure they where numbered.
If you look at the C4 connector with the lock pointing up the upper row start with 1 on the right and 10 on the left. Second row start with 11 on the right and end with 19 on the left.
If you look at C1 lock pointing up, upper row start with 1 on the right and end with 7 on the left.
Second row 8right-14left
So I'll take those pins, and ohm them to ground?
 

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This is only a confirmation that the wire is ok. Yes Ohm it to ground then you know it's no short circuit. Ohm pin 10 to pin 18 then you know the wire I ok.
 

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Discussion Starter #23
Sorry for the lack of update. When I removed the plugs looking for pins numbers I noticed the plug I removed from the tipm that all the pins were brown with dirt. Only the pin tips were shiny and clean. So I took electrical cleaner and q tips to the pins and cleaned them. Cleaned both the pins and plug from tipm, and from the pcm. Put it together, and the transmission has yet to go into limp mode since. I'm going on over a week now without limp mode. whereas before it would literally go in limp mode every day I drove the truck
 

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Discussion Starter #24
aaaaaand im back to square 1. truck threw another p0882 code. but was inactive when i read it again, and then it threw a p0750 code again.
i wasnt really holding my breath on cleaning the harness pins (although it was nice having a normal acting truck again for a while) it was normal for close to 2 weeks.

so now i need to get back into the wiring. and figuring out what pins i need to check resistance on, as the harnesses arent clearly labeled on what side what pin is on
 

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Discussion Starter #25
also, now that its getting cooler here in northern iowa, ive been noticing another issue, although im not sure its related to the issues ive mentioned already. if the trans temp is 80 degrees or below, when i first drive the truck, itll go into first, 2nd, then will hit 3rd gear, but then rapidly shift between 3rd and 2nd a bunch, until i let off the accelerator pedal. the truck has 240k on it, and the previous owner said the trans was done around 100k, but no paper work to prove this. when the trans is up to temp its very solid and firm. no hunting for gears.

could this all be tied into my shift solenoids, and or valve body?
 

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P0882 is TCM Input Power Low, which means that the main 12V power feed to the TCM (from the trans relay) has been cut. By the way, you have an ECM and a TCM (separate engine and trans controllers). A PCM is the combination of these two, and was used in 2010 and later 6.7L trucks.

The trans relay is in the Power Distribution Center (PDC) or Totally Integrated Power Module (TIPM), both of which names refer to the black box near the battery that contains fuses and relays. I don't know why there are two different names, or which model years use which name, but they essentially mean the same thing. In some cases, the trans relay is removable (and therefore, replaceable). In others, the trans relay is built into the main circuit board in the PDC/TIPM (so if it's bad you have to replace the whole thing). Again, I don't know which years have which style.

The trans relay receives direct battery power. When the relay is turned on, it feeds 12V power to the TCM (and to the trans). Loss of the 12V power to the trans will give you full limp-in mode (4th gear only, in Drive), and in fact the TCM commands limp-in mode by turning off the trans relay (the TCM controls the relay). The TCM is also fed with other 12V power, but the trans relay output is fed back to the TCM (at several different terminals on the TCM) so the TCM can check whether the power to the trans is present or not.

When you roll the ignition key out of the LOCK position, the TCM goes through an initialization routine. As part of this routine, it checks the trans relay output power. Initially, the trans relay is OFF. The TCM first checks to see that there is NOT 12V power on the trans relay output (if there is, it sets a P0883 [TCM Input Power High] fault). If that checks OK, it then commands the trans relay to close, and checks that there now IS 12V power coming from the relay. If not, you get the P0882 fault. Note that this is only checked at key-on. As far as I know, loss of power from the trans relay while driving will not set a P0882 fault (although I think the PDC/TIPM itself may set a fault if this happens). But it sounds like you're losing the 12V power feed from the relay to the TCM/ trans while driving (which gives you 4th gear only).

Diagnosing a P0882 can be difficult, especially if it's intermittent (as yours is). That's because an intermittent wiring problem (for example) will usually check OK when you test it with a meter. Also, if you jumper 12V into the trans relay output, you'll get a P0883 fault. I would check the wiring between the trans relay and the TCM (both the main 12V feed that goes to the TCM and trans, and the control wire that the TCM uses to turn the relay on and off). Note again that the trans relay output goes to several different terminals on the TCM (4, if I recall correctly). Check for open circuits, or for shorts to ground or into other circuits. But it sounds like you've already checked this, and again for intermittent issues it's unlikely you'll find the problem. So you could try replacing the trans relay if it's removable (if so, you can also swap it with one of the other relays as a test). If the relay is built into the main board, then maybe try another PDC/TIPM from a junkyard. Or simply assume the wiring is bad and run new wires in place of the existing ones.

FYI, you can find wiring diagrams and connector pinouts at rambodybuilder.com. You have to drill down through a series of PDFs to find these, and you have to use Internet Explorer (Chrome doesn't open the next PDF when you click the links). For a 2008 truck, I would instead look at the diagrams for 2009 MY (I think some of the 2008 diagrams still show the old 48RE trans wiring).
 

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Discussion Starter #27
I'm not seeing relays in my tipm. But I do have a few transmission related fuses. I have a 15a that is labeled aisin transmission controls (diesel only)
Then I have a 20a labeled aisin relay feed (diesel only)
And then a 10a labeled pcm(gas)/tcm (diesel 58rfe)
And a 30a labeled diesel pcm (diesel only) these fuses are all good.
I don't understand the aisin fuses as I don't have a aisin trans. But that's what they are labeled via my owner's manual
 

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Discussion Starter #28
Also, I've never checked resistance on any of the wiring, as I never knew which wire was which on my plugs. Some say there are numbers on the plugs itself but I couldn't find these, to even attempt to check resistance.
Every time I see the P0882 it is never a active code. And I don't get it all the time either..I can still clear that code. And for a while I was checking for codes every day. And not every day it would have the p0882 code, and other times it did.
And a few times I would check codes as the trans was in limp mode. And sometimes 0882 was there, and others it wasn't.
 

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Discussion Starter #29
iits been almost 5 weeks since i had a issue with low voltage and going into limp mode.
but tonite on my way to work, i hit limp mode, and a check engine light. p0882 again. only thnis time ity wont reset when restarting the truck. i was forced to drive it to work in 4th gear, so took all the back roads to keep the truck under 2k rpms and around 50mph.

this thing is pissing me off, and at the wrong time. expecting snow and ice here the next few days.
i still havent heard if the fuses i listed 2 posts up are related to this issue, or where i can start to tracce the correct wiring.

ill beg for help if i have to
 

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iits been almost 5 weeks since i had a issue with low voltage and going into limp mode.
but tonite on my way to work, i hit limp mode, and a check engine light. p0882 again. only thnis time ity wont reset when restarting the truck. i was forced to drive it to work in 4th gear, so took all the back roads to keep the truck under 2k rpms and around 50mph.

this thing is pissing me off, and at the wrong time. expecting snow and ice here the next few days.
i still havent heard if the fuses i listed 2 posts up are related to this issue, or where i can start to tracce the correct wiring.

ill beg for help if i have to
Check the resistance on the wiring between TCM and TIPM. See the website I spoke of earlier for wiring diagrams and connector pinouts. Or just find a shop that does electrical work and have them take a look at it.
 

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Discussion Starter #31
It is from the TIPM to the pcm. Code set when detecting under 3V.
If you disconnect C4 on the pcm and the C1 on the TIPM you can measure resistance on the pin 18 (C4) to ground. Tell you if there is a shortcut.. And resistance between pin18(C4) and pin 10 (C1)Should not be over 5 Ohm. At least that way you can confirm the cables are intact.
I tried checking resistance on 18 to ground, and can't get anything..not even a flicker. But I also have a cheap walmart multimeter that was flickering readings when touching probes to each other.
 

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Discussion Starter #32
So I took the truck to a Dodge dealership service department. They claim it needs a new pcm/tcm. They're saying it's an internal short..they tested the tipm and are not having voltage issues to supply the voltage to the pcm/tcm, but with the internal short it can't compute.
 

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Discussion Starter #33
well it took 2 weeks, but finally got a new tcm for my truck, and installed. will see if my issue with low voltage is resolved. ( take a few weeks of driving)
although i have a new issue, which ill make a new thread for
 

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Discussion Starter #34
so, heres an update, for those who care to hear, and or anyone else that may have a similar issue. i had the tcm installed by a dealership back in late november, early december. and still had issues with low voltage. called same dealership, and here i am 3.5 months later with still the same low voltage issues to the tcm. and going months with no communication. it seemed like i was doing all the leg work for communication. i kept getting the "oh were still looking into this, or we cant find the parts" mind you this time they were wanting to get tcm pigtails and rewire all the wires to the tcm. and or a new engine harness for the ripe price of $2,000. as the tcm isnt seperate from the ecu harness. i had finally had enough. i found and took my truck to a different dodge dealership. they had the truck monday through friday, and i got a call friday morning saying my truck was done. they found the main transmission plug was corroded horribly. they cut it off and spliced and sealed a new one into the harness. showed me the old plug, several of the wires were green from corrosion. i was surprised the transmission even functioned with this plug. they determined that plug shorted to itself, and grounded out, locking the transmission into limp mode, and wouldnt come back out of it. they also told me this plug hasnt been touched in a very long time, meaning the first dealer never unplugged the plug from the transmission, and that they believe that my truck more than likely didnt need the $1,000 tcm that i had installed. that left a sour taste in my mouth for sure.
but the truck is great now. no more banging from going to limp mode and what not. just wish i wouldve taken my truck to the 2nd dealer the first time.
amazing what can happen when a dealership tries to really earn your business, instead of throwing parts at the problem
 

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Great you finally solved it :) I hope my sometimes confusing answers did not make it worse.. Had big problems with the forum lately until i understood it was "windows explorer" messing it up.
 

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Discussion Starter #36
Great you finally solved it :) I hope my sometimes confusing answers did not make it worse.. Had big problems with the forum lately until i understood it was "windows explorer" messing it up.
im more than excited that the problems seem to be fixed now. but i did do about 5 months (or more from previous owners) of damage to the trans. it couldnt be easy on the trans or torque converter to lug a truck around in 4th gear so often and randomly. the last time it went into limp mode (before i took it to a different dealer) i thought the transmission was falling out of the truck. the banging back and forth from 6th-4th-6th-4th, the noises, the shaking, the mechanical violence. i thought for sure the trans was done for. and after that the trans was stuck completely in 4th gear limp mode and wouldnt come out no matter what i did. so i was for sure thinking the new dealer was gonna tell me they found the problem, but i was going to need a new transmission as well. but all is fairly well. i have a couple little issues now, but i can fix those without worrying the next time it will go into limp mode and potentially cause more issues
 
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