2004 Dodge Caravan P0700 Code: Limp Mode in 2nd Gear After Replacing Sensors and Solenoid Pack
My 2004 Dodge Caravan is stuck in limp mode, remaining in second gear despite replacing both input and output speed sensors, the transmission solenoid pack, and thoroughly inspecting the wiring harness for any broken or damaged wires—no issues were found. I disconnected the battery and left it overnight, then reconnected it this morning; the problem persists. The only component left that could be at fault is the transmission control module (TCM). I obtained a used TCM from a junkyard, but when I connected it, the vehicle died because the key fob lacks the specific chip required for that unit's security system. After reinstalling my original TCM, the vehicle started normally. My question: Is there any safe or legal way to bypass the security key on the used TCM to test if it resolves the limp mode? Or are there other potential causes I should investigate beyond the transmission control module? Thank you for your insights.
The P0700 code often indicates deeper issues—there may be additional diagnostic trouble codes (DTCs) present. Have you checked for any other codes besides P0700? Do you have a scanner? Yes or No? Have you verified the transmission fuse and relay status? "Only thing left is the TCM" — this is incorrect; the TCM is not typically the sole cause of P0700. "Is there any way to bypass the security key on the used TCM?" — No, and it's strongly advised against doing so. Bypassing security systems can lead to vehicle damage or safety risks.