Hello and welcome to Just answer.com, Super mechanic here. About your vehicle.
That code is an indication that the trans controller has requesteed that the PCM turn the light on.
There are many things that can cause that, however, there has been a service bulletin on some that has to do with the diode in the TCM power circuit.
You might want to try getting a non biased shop to confirm that there are no issues with the (rebuilt) trans.
Here is what one of the bulletins states. See if yours may be in this one.
Date: FEBRUARY, 2003
Model: 2000-2002 ACCENT ATM
ATM DIODE CORROSION IN THE CONTROL WIRING HARNESS
Some 2000-2002 MY Accent vehicles may experience ATM diode pin corrosion in the control wiring harness located behind the dash panel. Water from the cowl top panel may enter through an improperly sealed control wiring harness grommet in the dash panel.
A corroded ATM diode may result in the following symptoms:
|^||Diagnostic Trouble Code P0707 (Transaxle range switch - Open circuit) |
|^||Diagnostic Trouble Code P0708 (Transaxle range switch - Short circuit) |
|^||Diagnostic Trouble Code P1529 (M/L-on request signal to ECM |
|^||Diagnostic Trouble Code P1586 (Encoding signal circuit not rational) |
|^||Harsh shift and transaxle held in 3rd gear fail-safe |
If a vehicle with these symptoms is being serviced, follow the ATM diode replacement procedure provided in this TSB. Do not replace the automatic transaxle or control wiring harness.
|^||Model: 2000-2002 ACCENT vehicles with automatic transaxles |
|^||Affected vehicle production date range: Produced through April 30, 2002 |
|^||Affected vehicle identification number (VIN) range: |
|-||3 Door: Produced through KMHCG35CO2U22O100 |
|-||4 Door: Produced through KMHCG45C02U375204 |