Found this on another page.....
Originally Posted by vasau 
The vehicle came in with 2 trouble codes and complaint on a transmission shifting.
P1775 Solenoid Switch Valve Stuck in TCC.
P1784 LR Pressure Switch Circuit.
After clearing these 2 codes the van ran normal for about 20 minutes without any issue, but after, the problems came back with no codes.
LR Pressure Switch is always in "Open" position. Must be closed at Park, Rev and Neutral.
Could anyone explain to me how the switch works. Is this the solenoid pack or the LR Pressure issue?The L/R pressure switch should be closed in P/N only. The switch should open when put into REV if the trans is not in limp-in mode. All switches will stay CLOSED if the trans is in limp-in mode. Disconnect the trans 8-way connector at the solenoid pack. Key on scanner hooked up apply 12 volts to the L/R pressure switch pin in the 8-way connector and watch for the switch to change from open to closed. If it does change the SSV may be stuck in the TCC position. You will have to remove the valvebody and inspect the solenoid switch valve to know for sure. The pressure switch itself is in the solenoid pack. If you have an old solenoid pack changing it is easier and quicker than inspecting the valvebody. Perform your diag for fault P1784. I believe the pressure switch is also closed in 1st gear also. Hope this helps.
SOURCE: diagnostic code for dodge caravan 1996 P1784?
The code is about the switch that monitors the hydraulic pressure for operating the low/reverse clutch of the transmission. That clutch is called into play for all forward gears as well as reverse, so it seems reasonable if that clutch were not working that the car wouldn't move in any gear. I would begin by making sure that there is sufficient trans fluid by inspecting its dipstick. If needed only use ATF +4 but don't overfill it. Also, just on a chance, take a look underneath to see if you see any motion of either the left or right half axles (or one moving, but one not) which would be another reason for no motion due to a drive shaft disconnection or some such anomaly. Other than that, your problem could be with the Low/Reverse solenoid switch in the solenoid pack portion of the transmission (the box on the driver's side of the trans) being stuck. That can be repaired without removing and rebuilding the transmission so let us hope that may be the cause. I would have the car towed to a good independent trans shop that has a reputation for knowing how to service the Chrysler electronic transmission.
Hope this helps.
8,447 views
Usually answered in minutes!
×