Ok so here's the story I have a 98civic EX Cpe 5spd. The check engine light came on at the same time that the speedometer started to bounce. I had the code read and it said the O2 sensors were bad both of them. We'll then i noticed that the brake light on the cluster for the e-brake engagement only will flash on start up. And there is also a slight "pulsing" in the electrical. The light will sorta dim and brighten. and there is a little jump in the engine when it does this like it will speed up and slow down. Not significantly but just enuff to feel it. Could this be the ECU of the Speedometer head unit causeing this??? Please help.

 

someone help me??? Please??

 

Do ecu's go bad? If so, that's what it sounds like to me.

 

check the connections on the battery. clean them really well, and put vaseline on them to keep corrosion out. then if it still does it, go to a parts store and have them test your battery and alternator.

 

My guess will be the alternator. mine did sort of the same thing. CEL, dimming lights. I replaced the battery since it had died a few times, but it turned out to be the alt. Good luck.

 

the battery is actually clean but i will test the alt.

 

has anyone else heard of this happening?? Can an ECU actually go bad?

 

it can, but usually the car dies. im thinking batt, or alternator. most parts houses can test it for free.

 

i could see the alt as going bad. would that cause a "surge" in power??

 

hi did you find the prob?
i have got a civic 1991 vti import and now and again my speedo jumps
up when im sat still.i dont seem to have a prob with ellectrics tho its just the speedo
jumping.
can any1 help cheers