Chrysler Repair: 300m transmission: LR pressure switch code, solenoid pack, transmission control module

Question
Hello Roland, I have a 2002 Chrysler 300M and have began having problems with the transmission. We have had the transmission rebuilt, we have replaced the solenoid, we have replaced both sensors and the car is still doing the same thing. The code today says P0841 LR Pressure Switch Sensor. Not sure what this is? It is stuck in 1st gear, but when we reset the codes we can drive it a few times maybe 20 miles and it's fine but then it slips back into the limp mode i guess. I have been our so much money and have so many headaches that I didnt know where else to turn. I am gonna put hope in you. Can you help???   Thank you so much :)

Answer
Hi Tonia,
The 0841 number may be in error as I don't find it in the list. The LR pressure switch sensor cirucit is a valid code but its number is 1784, so you might want to verify the actual number from however you got it.
If it is that code the possible causes are that the wiring between the low/reverse sensor and the transmission control module is either 'open' or 'shorted' to ground or to a 12 volt-carrying wire, or that there is a problem in that LR solenoid itself which is in the solenoid pack, or that the bolts holding the valve body in place are loose, or that the internal filter inside the trans is clogged due to internal damage in the trans, or that the transcontrol module is faulty. All of these possibilites can be evaluated and then the proper 'fix' would be known. None, except internal damage, are going to require removal of the transmission for repair.
What is the past history (time/distance driven) since the rebuild, the solenoid (pack?) replacement, the sensors (speed?) replacement? Are any of these repairs still under warranty?
If so, see if you can get the mechanic to stand behind their prior repair at no cost to you. If not, then I would suggest that the wiring of the LR circuit be checked and if found faulty to repair the wiriing. Then check the pressure of the LR clutch and if not consistent with the position of the LR sensor to replace that solenoid/switch itself. If that doesn't correct it then replace the transmission control module proper.
But do check the warranty on all the work you have done and use whatever rights you have to get the diagnosis and repair under warranty.
Roland