I just bought a 2001 Sonata with 160k on it on Monday. I took it in for state inspection today, and it passed, but the mechanic told me that two codes had come up - 1529 and 720. I'm trying to figure out what these codes mean. Does anyone know?

I had noticed my transmission stickingmore today than previous times I drove it, and I'm pretty sure it was having difficulty shifting... However, it had seemed to get better... I went out to try to see if I could make it happen with a former mechanic, and it didn't happen, but the check engine light came on.

Are the light and codes related?

 

p1529 is telling you there is something wrong with the transmission. p0720 i think is a speed sensor don't remember right now. take it to the dealer show be the easiest fix.

 

Yes, the 2 codes are related. The P1529 code just means that theTCM (transmission control module) sent a signal to theECM (engine control module) to turnthe check engine lamp on because of the P0720 problem. The P0720 code os for anoutput speed sensor circuit malfunction in the transmission.

Bottom line, get the trans looked at.