Blinking D means the trans has an issue and logged a code. Run an obdii scanner (some auto part stores do this for free) and google the code it reports, then you can find which of the many possible issues it is. Typically the first thing to go on Honda transmissions are the pressure sensors, the code will help isolate.

 

https://acurazine.com/forums/3g-tl-2...switch-892223/

 

NEVER buy AM switches!! Bot dem AM switches once....total crapp lasted 2 weeks. Use OEMacuraparts.com That shutter means switches are bad. Cheers