Mitsubishi Repair: Drive mode light blinks, drive mode, transmission oil

Question
After transmition oil change with mitsubishi oil.
Drive mode light blinks after 20 minutes of highway runing.
Light goes off when switch motor off.
But problem repeat when drive highway.
Montero 2001 SR

Answer
Juan,
I'm not exactly sure what you're referring to with the 'Drive mode' light.  But you may want to check the owners manual for troubleshooting.  It may indicate a problem with the transmission not being able to shift into overdrive.  If you are unable to find what that blinking light indicates in your owners manual, have the place that changed your transmission oil inspect your transmission again.
Good luck!