code P1684
 

I posted this thread in the wrong place on this sight ( I'm new here, a reason not an excuse:o) but, any way. I have a problem with a 2002 PT that throws a P1684 code both with OBD center and an external reader. I understand that this is not a DTC ( something about the battery being disconnected or something) but the car is in "limp home mode" and I don't know what to check? Fluid and filter have been changed (ATF +4) which did not resolve issue. How does one determine if TCM is good or bad if no codes are showing? Thanks

You are right about the 1684 code not being significant. It merely means that sometime in the last 50 starts of the engine, tha battery was disconnected.

You need a more sophisticated reader to read transmission codes. A basic OBD code reader will not be able to pick them up.

A Chrysler dealer will have a DRB III (Diagnostic Readout Box) which is a far more sophisticated readout device That can also control certain onboard computer functions and do much more than simply read codes.

A well equipped transmission shop will also have devices to diagnose tranmission ills. There are many possible reasons why the transmission is in limp mode and there's no real point in guessing about it here. Get some professional help.

P1684
 

Thanks for the info. Will follow up when I know more.