I'm having this same problem with my 95 accord lx. Ill drive for about 20 mins on the highway and then my check engine light comes on, shortly after the D4 light blinks. but the car still runs fine and shifts good. I did a 0 to 70 test going on to the highway and the only thing in noticed was it took a bit longer to shift from 3rd to 4th.

I pulled my code and got a trans code of 10, and the only thing i could find said it was water temp sensor.

My engine code gave me 6 12 and 17,

Not trying to threadjack with my problem, but they seem the same. maybe you'll pull the same code.

 

6 = engine water-temperature sensor

12 = EGR valve lift insufficient

17 = VSS for a manual-trans car (???)
My list is from a 98-02 book, so maybe code 17 in the earlier cars simply means that there is some kind of transmission code & you should look at the flashing D4 lamp (which you have done)

 

D4 code 10 and CEL code 6 are both for the engine coolant temperature sensor. This is located below the distributor and has two wires going to it. I think it has a black or brown electrical connector.

Unplug that sensor and see if there is any oil, dirt, corrosion that would cause it to have a poor contact.

CEL code 17 is for the VSS. The D4 light should have flashed a code 4 with that.

CEL code 12 is for the EGR lift valve.

I would also pull the 7.5 amp backup/radio fuse in the engine bay fuse box for a minute to clear the ECU. Then drive the car for a bit until the CEL and/or the D4 light start flashing. Then recheck the codes.

 

Is the d4 code 4 for the trans speed sensor? If so I changed that out 2 days ago, I thought that might of been the problem. It hasnt stopped the light from flashing not one if the mounts on the speed sensor was broken

 

When you installed the new VSS, did you install the tiny drive link between the sensor and transmission gears? If not, then VSS won't work.

I would suggest trying to fix VSS code first and then see what happens w/ a system reset.

good luck

 

Yea, that part is installed right, the speedometer is working.

 

I found 2 of what I think where the coolant temp sensors, they were both 2 wire green plugs. I pulled the electrical plug off and there was no corrosion or dirt. Should I go ahead and just replace the 2 sensors?

I also reset the ecu by pulling the fuse and no code have popped up yet.

 

The green plugs are for the fan switches and will not cause the check engine light to turn on.

The engine coolant sensor is below the distributor. You almost have to remove the distributor to get to it.

 

Ok, ill try again in the morning when I get off work.

I also drive 40 miles on the hwy after my last post and none of the lights have come back on yet

 

The D4 and engine light came on again on my way back from work, this time its only 6 and 12 for the engine and 10 for the trans. Waiting for it too cool off now before I mess with the coolant temp sensor. I think I did finally see it though and its pretty well covered in stuff.