TCC Solenoid CEL with P0740/P0700 - What Next??
 

Thanks for taking the time to read! I really do appreciate it!

I have a 2003 Dodge Ram 1500 4X4 with the 5.7L V8 and 545RFE Transmission. It has 161K miles. Purchased it a little while ago and I did not know the last time that the transmission fluid had been changed. The fluid didn't smell new (maybe a tiny bit burned) and barely detectable grit in it. It recently threw a CEL with the generic P0700 and the P0740 Torque Converter Clutch Circuit / Open. Did a BUNCH of reading in these (GREAT!) forums and dropped the transmission pan, cleaned it, cleaned the magnet, changed the 2 filters and refilled with ATF+4 to the proper level. Well.... after about 2 weeks, the same CEL came back.

Next step depends on you guys that know A LOT more about this stuff than I do. Seems like one of three things that need to be done to rectify the issue. Would prefer not to shotgun expensive options first but if that is what needs to be done, I would. What to be done first?? Do I do another transmission drain and refill (at about $45) hoping it was the dirty fluid, or change the solenoid pack and upgrade to the white plug (at about $250) or have the tranny dropped and change the torque converter?? (cost is one arm and half of a leg)

Or, is there something else that I would need to do?? I think that I have narrowed it down, but TOTALLY could have missed something.

Thank you VERY much for reading this over. Hope that you have a GREAT New Years!

Just bought the new WHITE shift solenoid pack on your suggestion. Thank you! Should be a fairly easy install, but any tips or tricks that you can think of??

Also, not sure what the TCM (transmission control module??) relearn is. Does that require a factory 2 way code tool to tell the tranny to reset and relearn shifting??

Thanks again for your time!

Well, I received the white connector solenoid pack with the TRS plate. Everything went together without a hitch... filled it back up with ATF+4 and let it shift through all the gears. ANNNNNDDDDD...it threw a check engine light with the same codes. You guys would know far better than me, but the only other reasonable thing that it could be is the torque converter right?? Drop the tranny and replace the converter?! Soooooo looking forward to being able to do that! (sarcasm included!) Anything else that it could be??

Also, with 161,000 miles, if money is tight do I still do a rebuild on the transmission while it is out or wait?? I detect zero slippage and zero other problems with the transmission. Everything else is good!

Thanks for the time and thanks for the input!

Sorry. I could very well be wrong but for what its worth...
P0740 is saying the TCC circuit is open. Which to me indicates a wiring or electrical issue. It doesnt indicate a hydraulic issue. You have already changed the shift pack which should indicate that was not the issue. I think I would look more closely at related wiring ?
i believe the TCC is also controlled by temperature. Im not sure if its engine temperature or transmission temp. I do know on my 03 on cold starts and driving the TCC will not engage until some warm up haa occurred .
just for what its worth
good luck

You have a bad wire or your tranny temperature sensor (that's why I quoted you) is bad. OD and Lockup go off if the tranny temp sensor. That's why northern trucks have the tranny fluid run through the radiator, to warm it up quicker and give you your full 5 gears.

Fanatic....dont understand your post. My truck does not have an issue! ? OP truck may have this issue tho.....

Sincerely hope that that is the problem. Wondering if it would be best to pay an hour to the Dodge Stealer (ummmm.... I mean dealer) to have them diagnose which wire is the issue. I think that might be it as there have been a couple of other wires that possibly had some mice that had a little after midnight snack. The tell tale sign?? Mice poop in on the top of the engine!

Would it be a fairly easy thing for me to troubleshoot?? Is the wire relatively straightforward?? I am researching right now where the stinkin' wire is located on the 545rfe. I'll find it! Ha Ha!~

THANK YOU SO much for your help!

Ya...he meant me and I think that you are TOTALLY right. I think wiring is the key as there were the signs of mice previously. Just trying to find the related wire.

Thanks for the time!