When the D5 light is flashing while driving, an error in the transmission system has been detected and you would need to retrieve the trouble code to proceed with diagnosis and rectification.
Aug 4, 2009 at 2:26 PM
Repair Safety Notice: This information is for general instructional purposes only. Vehicle repair can be dangerous. Verify all information, follow manufacturer service procedures, use proper tools and safety equipment, and consult a qualified repair shop when needed.