Hyundai Repair: hyundai 99 excel,no reverse and no 1st or 2nd drive, transmission control module tcm, transmission control module

Question
hi,i own a 99 excel 1.6 and today i had no reverse or drive in any gear..the fluid level was fine,up until today an just recently it would not change into overdrive or just stay in third gear,until i stopped the vehicle turned the ignition off then it would drive as normal..any help would be greatly appreciated

Answer
Third gear (and reverse) only is the failsafe mode of the transmission control module (TCM).  If it sees a problem that interferes with its ability to properly operate the transmission, it'll put the transmission in third gear.  Once the engine is turned off and restarted, failsafe won't happen again until the TCM again sees the problem.

The fact that you had no reverse and the vehicle would not move suggests you probably have a major mechanical problem in the transmission.  

A faulty transmission range switch, however can potentially cause these symptoms as well.

The first place to start is to check the trouble codes in the TCM.  This will give us information as to why the transmission was being put in failsafe.  From this information, we can then better assess what is necessary for repair.

Simply follow up with the trouble code numbers, and I'll let you know what I think.  Auto Zone and AAMCO have advertised they'll check trouble codes for free, but I've heard mixed reports as to whether their tools will read codes from the TCM.