I have a 98 civic dx coupe 5 speed, My check engine light came on one day after i started the car and pressed the throttle, and at the same time the speedometer started jumping around when the thottle was pressed. the were 2 codes EDL voltage high and one for the 02 sensor. When I cleared the code they came right back and after i drove it all the electrical stuff in the car started surging, ie; lights, engine, lights in the cluster. I replaced the altenator and the ELD, the surging of the lights and engine went away but the speedometer still jumps around and when hooked to a scan tool it says that the car is going 160 miles an hour and once it goes to 4000 rpm the engine wants to cut out if i unhook the speed sensor it doesn't cut out at 4 grand. the ELD code is still there and so are the O2 codes. does anybody have any ideas? Could it be a bad speed sensor (I replaced the ELD about a month before I replaced the altenator thinking it was just bad ELD, and I have tried a different ecm)

 

noops,

if you are still around, let me know. I'm dealing with very similar problems on my 98 dx. My speedo went dead, MIL came on, and 3 codes...the 02 sensors and a High voltage code.I had a fuse blow too (the speed sensor/alternator fuse)I took it to a shop and they said it was most likely the alternator, but I'm not buying that. Fuses blow when there's too much current being drawn, not produced. I unplugged the o2 sensors and the fuse still blew again. I unplugged myspeedometer in the dash and the fuseblew again. All wiring looksand wire harnesses look tobe in good shape.

what fixed it for you?was it a faulty speed sensor all along?

Matt

 

I did find the answer to this problem. See my other posts for the solution.

https://www.hondacivicforum.com/m_501475/tm.htm