2012 Ram 3500

[Jonwiley5]

Hello I am new to this so here goes!

I have a 2012 Ram 3500 with the 6.7 with 265xxx and when I bought the truck I noticed it wasn’t shifting just exactly right, it seemed to shift out into high gear too early and it wasn’t shifting out very smoothly at all. So I done a pan drop and filter change (actually done two within about a thousand miles) and that seamed to help, I also replaced both speed sensors and the pressure sensor on the trans and that seemed to smooth it out some as well. I keep getting two codes only on start up sometimes it will be a week or so before I get them and sometimes it’s a couple times a week. They are P0934 and P040D. Any help would be appreciated. Trans does not slip! Also when it’s shifting from third to forth it acts like it’s having a hard time finding the gear! Don’t know what’s going on there either?

 

[mtnrider]

P0934 is Hydraulic Pressure Sensor Circuit Low. and P040D is EGR temperature sensor high.

Is the truck tuned by chance? May be a electrical or sensor problem (if you are lucky).


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[MADDOG]

Welcome to RamForum.

Code P0934: Low hydraulic pressure. If the ECM detects a problem in the pressure sensor or the pressure sensor circuit, such as unexpected voltage, it will treat this as a fault and stop using the sensor for feedback. The ECM will store a diagnostic trouble code (DTC) in system memory and illuminate the malfunction indicator lamp (MIL). It could be a bad sensor, a chafe or short in the wiring or transmission fluid level. When starting up, and the unit is cold, low pressure may occur during a short interval after startup until the fluid warms and expands.

Here's a RamForum thread on another potential issue that causes this code:

https://www.ramforum.com/threads/transmision-code-p0934.154771/

Code P040D: EGR Temp Sensor A Circuit High. The code P040D Exhaust Gas Recirculation Temperature Sensor A Circuit High is set by the ECM when there is a detected a high electrical value within the EGR Temperature Sensor.

Causes of a P040D code are:

• Defective or damaged EGR (Exhaust Gas Recirculation) temperature sensor
• EGR temperature sensor gasket leaking
• Cracked or leaking exhaust pipe in which the sensor is mounted
• Burnt wiring harness and/or sensor
• Damaged wire(s) (open, short to power, short to ground, etc.)
• Damaged or dirty connector to the ECM (Engine Control Module)

Did the P0934 code pop up during the first startup after you replaced the speed & pressure sensors? If so, when the work was done the wiring was disconnected and that could throw a code. One fix for that is to disconnect the negative cable on the battery for 30 minutes, then reconnect and start the truck.

I'd suspect the EGR temp sensor would be the first item to check due to it's location and being subjected to high temperature & corrosive gasses.

Good luck!

 

[Jonwiley5]

P0934 is Hydraulic Pressure Sensor Circuit Low. and P040D is EGR temperature sensor high.

Is the truck tuned by chance? May be a electrical or sensor problem (if you are lucky).


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I’m not sure if it’s been tuned or not it has had egr valve and egr cooler deleted as well at muffler and cat delete this was all done before I purchased the truck. At times for whatever reason it seems to shift out perfectly fine. I disconnected the battery’s for about ten minutes and then hooked them back up and started the truck and the codes popped up and went off to town and it’s shifting out smooth as silk. I’m just lost as to why it’s fine one minute and the next it’s shifting out rough.

 

[G. Mcpherson]

It Has been Deleted.

 

[mtnrider]

I’m not sure if it’s been tuned or not it has had egr valve and egr cooler deleted as well at muffler and cat delete this was all done before I purchased the truck. At times for whatever reason it seems to shift out perfectly fine. I disconnected the battery’s for about ten minutes and then hooked them back up and started the truck and the codes popped up and went off to town and it’s shifting out smooth as silk. I’m just lost as to why it’s fine one minute and the next it’s shifting out rough.

You are tuned and deleted. With that said you should not have the EGR code so that may be a tuning issue. I'm guessing you did not get the tuner with the truck? If you did you might want to try and go back to stock then re-load the tune.

As far as the transmission code, hopefully it's just a sensor but being tuned you are playing with fire as far as transmission life is concerned.


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[Jonwiley5]

I did not get a tuner with the truck.

 

[Jonwiley5]

What would be a recommended tuner. I had planes on getting one I just have to wait till I get the funds.

 

[mtnrider]

I did not get a tuner with the truck.

You might be screwed on the EGR one then. It's throwing a code for something that isn't even there any more so tuning is the most likely culprit.

Hate when people sell a truck and don't include the tuner. They really screw the next owner and I see it every day. You only option may be to source new tuning/tuner but that is getting extremely difficult to get now and not cheap.

 

[Jonwiley5]

Thanks for your information. I love the truck just hate the code popping up. And as of right now it’s shifting great. But it has a mind of its own and at times shift crazy!