Someone good with diagnostics, your help is needed

[DizzyFranco]

I'll post the error codes, what I've looked at, and any info I think of adding or is requested.
I posted in DIY but no response so I think it was the wrong category to ask for help.
I just need some help finding out where the problem is that's causing my truck to throw all these codes...
I believe its my IAT sensor or TCM sensor that might need replacement or rewiring, but I'm not sure where to find them or which wires to follow and probe.
I have a 2012 Express RAM 5.7L Crewcab, tranny in limp mode several days now. I have driven it when absolutely necessary but I try not to.

P0113 - High air intake temperature sensor
P0750 - Shift solenoid A
P0882 - TCM Power Input Signal Low
P0846 - Transmission Fluid Pressure Sensor/Switch B Circuit Range/Performance
P0871 - Transmission Fluid Pressure Sensor/Switch C Circuit Range/Performance
P0988 - Transmission Fluid Pressure Sensor/Switch E Circuit Range/Performance
P0876 - Transmission Fluid Pressure Sensor/Switch D Circuit Range/Performance
P0869 - Transmission Fluid Pressure High

please advise.

I checked the fuse and relay for the TCM and theyre ok.
if somebody can give me a clue as to where to look, I'd really appreciate it.

when I try a hard reset (key on/off 3 times) before starting, it will sometimes
work as normal, 30 mins max, shifts all gears, but once i come to a stop it returns to limp mode 4th gear only.

Thanks in advance

 

[NETim]

How good is your battery? Has it been load tested? TCM issues can be caused by a bad battery, bad battery connections i.e., corroded/dirty, corroded connections on the TCM itself etc.

Same for IAT, check the connections, clean them. Could be the IAT is *****.

Multiple issues like this push me in the direction of bad battery, connections and corroded ground connections. If everything is nice clean and tight, then maybe it's time for a new TCM and IAT.

 

[RamRod37]

seeing how the TIPM (Fuse box) is prone to going bad I would say you have a wiring issue and the TIPM would be the best starting point since this code is in the list P0882 - TCM Power Input Signal Low code being low power if its low I will cause all the others to follow even possible the P0113 - High air intake temperature sensor I think lower voltage than the input voltage is sent back to PCM/TCM so if voltage coming in is lower than spec then so will output voltage yeah wiring or TIPM (fuse Box) one of the two

 

[caulk04]

Get a quality wiring diagram, you can buy into factory data for short term and it's quite reasonable. I forget the source though... Very helpful.

Look for a shared power source or shared ground between those systems, I'd gather you'll find some poor rotted connection/wire.

 

[RamRod37]

deleted

 

[Burla]

How good is your battery? Has it been load tested? TCM issues can be caused by a bad battery, bad battery connections i.e., corroded/dirty, corroded connections on the TCM itself etc.

Same for IAT, check the connections, clean them. Could be the IAT is *****.

Multiple issues like this push me in the direction of bad battery, connections and corroded ground connections. If everything is nice clean and tight, then maybe it's time for a new TCM and IAT.

Yes. first how old is battery.

Condition of tranny fluid? Is the level fill top? 65rfe?

 

[Burla]

I believe if it was TIPM you wouldnt go to limp, the symptoms would be far worse. If you end up at solenoid pack, get the white one.

 

[huntergreen]

Interesting, but my first thought was the sensor pack attached to valleys crapped out.

 

[DizzyFranco]

I hope you're right @NETim, one of those sensors or even having to replace both is not bad. $40 - 60 parts... but if its the Solenoid... that like a $600 part, and I'm assuming it's not easy to get it out. I did one on an acura tsx a while back and it was kind of a b-word.

@RamRod37 you're absolutely right about that, could be just one thing triggering all the other codes, I will check that wiring first thing along with all the other suggestions from the guys.

I have a book for our trucks, a repair manual. Do you think the Diagrams in those are enough or are there better ones out there @caulk04 ?

@Burla My battery seems good, but I have not had it load tested. I was only assuming it was good because I haven't had any trouble starting/turning the engine. But I guess its possible... could also be that my alternator is not working properly? someone said that I forgot where I heard it.
Fluid level is at topped, condition normal, and not 100% sure which tran I have, but that sounds about right 65rfe. I'll have to check with my VIN to see what I have...unless you guys know where to look physically look and see what I have.

Hey @huntergreen, what's this sensor pack you speak of, and valleys? sorry I'm new to some of the lingo here.

I don't have a battery tester at home, so for now I will just be checking everything that I am able to... I do have a voltmeter and a multi-tester handy...
I'll have to look in the repair manual for info on finding the IAT and TCM sensors and how to test them. most likely some sort of resistance reading on the terminals or whatnot. Also will check for wiring messes once I find a diagram and figure out which wires to follow.
Thanks alot for the input guys . if anyone knows any ways I can check the battery on my own or any other shortcuts for testing some of the different components involved... do tell.
Thanks Again
BRB

 

[Jeepwalker]

Take your truck/battery to a parts store, they can do a load test. That's what you need to do.

Quadruple check wiring.

There are some less expensive solenoid options. IDK if it's worth it considering the amt of work if it fails. I'd probably read the tranny section in the service manual before i went down the road of a new solenoid. There should be a trouble-shooting tree.

 

[DizzyFranco]

Genius, I didn't even think of that. I'll get the battery tested tomorrow when they open. Just off my gut feeling though, I feel like, if it was a thing with just a bad battery, we would hear a heck of alot more people running into this limp mode thing. And this is the first time I'm hearing of this. I've also had a bad battery before... but you never know with these robot vehicles we drive around these days. All Compugetized lol

Thanks @Jeepwalker quadruple checking wiring now and serv manual

 

[RamDiver]

Additional note:

Most auto parts stores will load test your battery for no fee and it is almost always the ideal first step when chasing any electrical weirdness.

.

 

[Ludville1]

I have the same issue with my truck going into limp mode after roughly 20 miles of driving. It has code PO841, so I replaced the transmission fluid pressure, still does it. Then I removed/cleaned the connection to the shift solenoid, still does it. I suspect a connector/wiring issue in mine.

 

[18CrewDually]

All those codes I'd inspect the transmission wiring harness carefully for a chafe. Also check and clean grounds. Remove, inspect, and fully latch the plugs at the trans and TCM.

 

[huntergreen]

I'll post the error codes, what I've looked at, and any info I think of adding or is requested.
I posted in DIY but no response so I think it was the wrong category to ask for help.
I just need some help finding out where the problem is that's causing my truck to throw all these codes...
I believe its my IAT sensor or TCM sensor that might need replacement or rewiring, but I'm not sure where to find them or which wires to follow and probe.
I have a 2012 Express RAM 5.7L Crewcab, tranny in limp mode several days now. I have driven it when absolutely necessary but I try not to.

P0113 - High air intake temperature sensor
P0750 - Shift solenoid A
P0882 - TCM Power Input Signal Low
P0846 - Transmission Fluid Pressure Sensor/Switch B Circuit Range/Performance
P0871 - Transmission Fluid Pressure Sensor/Switch C Circuit Range/Performance
P0988 - Transmission Fluid Pressure Sensor/Switch E Circuit Range/Performance
P0876 - Transmission Fluid Pressure Sensor/Switch D Circuit Range/Performance
P0869 - Transmission Fluid Pressure High

please advise.

I checked the fuse and relay for the TCM and theyre ok.
if somebody can give me a clue as to where to look, I'd really appreciate it.

when I try a hard reset (key on/off 3 times) before starting, it will sometimes
work as normal, 30 mins max, shifts all gears, but once i come to a stop it returns to limp mode 4th gear only.

Thanks in advance

Inside your trans there is a sensor pack attached to the valley. You can Google a pic. Keep in mind though, a weak battery can cause funky codes to pop up. That being said, I haven’t heard of an older battery causing limp mode.

 

[Burla]

Whenever you see a bunch of codes like this, the battery is the first suspect, that is why a couple us said that, and it sounds by the OP this battery is a little old? One or two related codes, not so much, but when you see a smorgus board of codes = battery is a suspect.

 

[Jeepwalker]

It's probably NOT the battery, but these trucks ...and most modern vehcles are real 'touchy' on electronics and grounds. It wouldn't be a bad idea to unhook a battery cable and leave it unhooked for an hour. See if that helps. Probably won't but ya never know.

There are some grounds behind an inspection door above the front tire worth checking. They get real rusty in the Northern states.

Chances are it's in the tranny (solenoid, sensor, or other). But you'd sure hate to change a lot of trans parts and find out it was a bad ground/wire/computer snafu.

 

[Hagar1]

Before you go throwing a bunch of expensive parts at it, check the grounds as well as the battery. With all those codes, I think that a ground issue may be the problem.

 

[DizzyFranco]

@huntergreen @Burla @Hagar1 @Jeepwalker @RamDiver @Ludville1 Thank you guys so much for the continued support. I'm doing everything suggested and I'm down to the TCM or Solenoid being the issue Battery was good, I checked all the grounds, Even detached them and ran a wire brush at the contact points with my drill gun to try and make sure its got a good clean connection.
So... Is there some way to test the solenoid without draining the trans fluid? Dont think so. And where exactly is the TCM? Is it on the outside wall of the transmission by the sift cable? Is there a test I can run for this? Its the cheaper 1 of the 2 but idk if I should just try teplacing it.

If I end up needing the solenoid, should get a trans fluid filter as well ? Orr should I wait to make sure the new solenoid fixes it the issue AND THEN do a trans fluid & filter change.

Here are some pix of what I found at autozone. $71 & $369 respectively

 

[Jeepwalker]

You 'should' be able to test it with a 'good' scan tool, or AlfaOBD (google this forum). But right now you might not have such a tool and it doesn't do you any good today, unless you know a buddy or have a good relationship with a shop which can test it.

But if you did have access to a scan tool, there should be a transmission functional test. Or run the tranny through it's paces and watch the position (readings) of the solenoid pack via the scan tool. A current Snap-on scan tool, or the dealer would be able to read it (which would cost you a service call and some waiting). Or ...like I said, if you downloaded AlfaOBD software & bought a OBD device, like OBDLink MX Plus for an android/windows device.