Hyundai Repair: 1999 Hyundai Sonata accelerator no power and several error codes, crankshaft position sensor, crankshaft sensor

Question
My 1999 sonata 4 cyl auto transmission stalled the other day. The accelerator had no power and car was not moving upon pressing it. I turned the engine off to restart the car and then it wouldnt turn on. Next day it started fine and has been running fine since then. But i am afraid the same could happen again. I got the codes read and the following cods showed up:
P0335 crankshift position ... A
P0765 solenoid
P0755 Solenoid
P0725 engine speed sensor
Could the acceleration problem be due to one of these codes? How bad are the codes and how important are they to be fixed? Also, how difficult is to fix them and how approximately much would they cost?

I am not a car expert thats why asking so many questions and will greatly appreciate help on this.
Thanks.

Answer
Hi, Nit.  Your acceleration problem could be related to all of these codes.  As I look at these codes, they fit into two different sorts of problems.

P0335 indicates that the engine control module (ECM) is not receiving the proper information regarding cranksahft speed and position from the crankshaft sensor.  And P0725 indicates that the transmission control module (TCM) is not receiving this information from the ECM, which it obviously cannot if the ECM is not receiving the proper information.  I've not seen this code that it wasn't related to a problem in the crankshaft position sensor itself.  Sometimes, however, I've seen failure of the sensor caused by teeth coming off the timing belt and getting wedged against the sensor, causing it to fail.  I'd recommend replacing the crankshaft position sensor, and if it hasn't been done recently, also replacing the timing belt.

P0755 indicates an issue with the circuit for the underdrive solenoid in the transmission, and P0765 indicates an issue with the circuit for the overdrive solenoid in the transmission.  When either of these codes sets, the TCM will put the transmission in failsafe (3rd gear only).  This will cause a lack of power accelerating from a stop.  Based on information in technical service bulletin (TSB) 09-AT-018, I'd recommend first inspecting the wiring going to the transmission visually, and if no issues with rub-through are observed, replacing both the under- and overdrive solenoids as well as the wiring harness inside the transmission.