Hyundai Repair: Whats Wrong, hyundai santa fe, transmission control module

Question
My 2001 Hyundai Santa Fe out of the blue started having slow acceleration and not changing gears smoothly.  I also discovered that when I change the car out of park into drive it makes a pop and jerks.

Answer
There are any number of possible causes, most of which are related to your transmission and the sensors that are used in the electronic control of your transmission.  Normally, these symptoms would result in a diagnostic trouble code being stored and the check engine lamp being turned on.

First, I'd recommend checking the transmission fluid level.  If low, inspect for leaks and top off with only SPIII transmission fluid.

After that, I'd recommend reading the diagnostic trouble codes stored in the engine control module (ECM) and transmission control module (TCM).