Ive got a 96 accord ex-l v6 with 175k. I've had NO problems up till now.
All of a sudden My cruise control kicked out, speedo dropped from 75mph to 0, Check enging light came on, and D4 light started flashing.
So I did the self check, and the CEL light blinked 7 long times, the D4 light blinked 4 short times. All my Chiltons says about the CEL is a automatic transmission problem.
It happens on and off. I have noticed that it seems like the lock up converter isn't working when the light D4 light flashes. Then If I shut the car off it comes back fine (of course with the cel on)
It runs so well!! I don't get it, is does seem eletrical and not mechanical, but not sure. ANY help would be appericated!! Brian

 

sounds like a VSS, try your cruise control (when speedo isn't working) if the cruise doesn't work then there is a good chance that your VSS is bad, I didn't double check the code you gave so I could be wrong but 90% of the time if the speedo isn't working and the D4 light flashes it's the vss...

 

Thanks Nasty!
I did check the cruise after I read your reply, and this is my result.
Pushing the MAIN cruise button (far left dash) the little green light comes on. on the switch itself, however,
after I turn the main switch on then I hit the cruise button (steering wheel) NO green light comes up on the instrument cluster it's in the top right corner. So no cruise..
I did take the vss out and kinda cleaned it (lot of greese in the little spring and such, put back togeather, and NO speedometer at all, or so for the short test drive I did..
I'm hoping this is the problem as it seems an easy fix, I just hope not a $3500 tranny. btw don know if this helps any but the date of manfacture is 08-96

 

You should recheck the CEL code. It should be code 17 (1-long flash + 7 short flashes). That is code for VSS. Code 4 on D4 light is trans code and also indicates failed VSS. Part is readily available for <$25 on ebay and elsewhere.

good luck

 

Ok rechecked the CEL code. I could be reading it wrong, but it seems like it flashes 7 long times, then nothing for a few seconds. Then it starts flashing it again..
All of the flashes seem to be of equal length in time, but the D4 light is just a blink. It does that 4 times then stops, then it does it again.
But like I said I could be very well reading it wrong, I don't have a lot of experience with this.. Thanks so much for the suggestions,
I looked up the part on ebay and found it for like 13 bucks plus 12 to ship it so for sure it's worth a try!! Ohh yeah I also saw the part listed for like $200!!
I'll try the $25 part and write back my results.. Thanks again! Brian

 

The long flash has CEL illuminated for perhaps 1-2 secs, while 7 shorts should be perhaps 1/4-sec apiece. There will be a long (1-2 sec) pause between repeats of the code.

TCU Code 4 is definitely the VSS, and as you found the part is relatively inexpensive.

Code 7 is Throttle Position Sensor, which is rare code and would have no affect on vehicle speed to my knowledge.

good luck

 

7 long blinks = code 70 (p1660) problem in the a/t fi line. this can bebecause of the a/t dtc. so either clear the code and wait for it to recode or replace the VSS, clear the code, and see what happens. if you want i'll post some diag info on 70.

 

Update
Ok guys took the advice, purchased a vss sensor from ebay. Installed it last night about 10 minute job, cleared the ecu code and then took it for a test drive. Speedometer, curise control, lock-up converter all function 100% normal now!!! Thanks soo much for the help, I know I've saved quite a bit of money. Man this car runs soo good!! Plenty of power as well.. Thanks again for taking the time to help guys..
Cheers Brian