Just bought this car The other day. Guy told me the tranny was overheating and had a vibration before I bought it. Drive it for a while and the d4 light flashes even if its in another gear, and SOMETIMES the CEL will come on, but not every time. Most of the time the speedometer doesn't work. When it stops the odometer stops too. We think the vibration is from a broken motor mount Bought this car for $500 as a project car to fix up and build. Question is: what's the deal with the d4 flashing and you guys think I got a fair deal? Pics of car on prof.

 

that depends on what year it is and if you have mechanical ability you could potentially be looking at a $1,500-$2,000 dollar transmission overhaul or complete replacement. flashing D4 usually means a toasted trans but also could be a variety of sensors like the trans range which cost around $50 dollars and easy to replace. you need to get the codes checked to find out exactly what's happening. there's a very high chance you need a new transmission. check this vid on how to check codes http://honda-tech.com/showthread.php?t=1901557 check here on reading blinking D4 codes http://honda-tech.com/showthread.php?t=1901557

 

Could be a lose ground from the trans to the frame of the vehicle. I ran one in my Tl from a bolt on the trans to the battery tray bolt using 2 gauge wire.

or it could be this