the3lracer

I have a 1998 Civic DX, stock motor, 5-speed. A few years back I replaced it with a '98 EX cluster so I had the tach (but swapped the speedos so it's still the original one), and recently I started having a problem. Randomly the speedo will go from whatever correct speed it is displaying to a constant 20mph, regardless of speed. It will also randomly bounce back to normal. Here are some further details regarding the problem:

-When rolling slowly (regardless of clutch in/out or in/out of gear) meaning actual speed is <20mph, the needle oscillates between 15-20mph. The speed of this oscillation IS SPEED DEPENDENT.
-When the speedo "resets itself" from 20mph to normal, it ALWAYS bounces to 0mph, then to the correct speed. Along the same line, when the speedo goes to 20mph from normal, it will ALWAYS rapidly climb 10-15mph before going to 20mph.
-On several occasions, the needle will oscillate between 30-40mph on ENGINE STARTUP.
-Normal, or even large, road bumps VERY RARELY cause this to happen - it happens more often on smooth pavement.

This is a Central PA driven car its entire life (I am the second owner, bought at 97k miles with no problems), and driven significantly in the winter, in case it might be an issue with water/snow/road salt. Any help would be greatly appreciated, even though I have done the math and can figure out my speed based off my gear and RPM. THANKS!!!

SpoonfedCivic

Ok there are only a few things that can cause this issue. First thing you need to check is fuse number 15 under your dash. If this fuse is blown, then you will need to check the section of your engine harness that is located under your intake manifold. There is a bracket that the harness will rub against and cause a short that is connected to the VSS which is connected to your speedometer. So check that first, if that's not the problem then check the voltage going to your VSS, or just spend the $100 to replace it and see if that fixes the issue. Get the new VSS from either Honda or O'Reilleys not Autozone. Because Autozone will not take the part back if it has been installed. If neither of these suggestions work, then you have a wiring issue and need to download a wiring schematic and start tracing wires. You could also try replacing your cluster and seeing if that works. Good luck.

HatchB16

I have the same problem with mine, it worked for a day but after i filled up on gas and rolled back the trip it just stopped working and now just bounces all over the place... thinking about just getting a new cluster because the mileage stopped working awhile ago.

CiNCY97civicEX

definately check the fuse number 15 under your dash as spoonfedcivic saidi had this very same issue with my 97 ex but mine was also accompanied by flashing lights, occasionally my car would die, and it does not let your alternator charge the battery so i constantly had to get a jump or charge it i had several wires under my intake manifold bracket that were rubbing the cost to fix it was only the price of electrical tape some currogated tubing from local auto parts store and a replacement 7a fuse.

Former User

Any CEL codes?

I have a scan tool that not only pulls CEL codes but also reads live data, such as mph. If you could borrow such a tool from somebody and find that the mph signal from the ECU is fine and does not fluctuate, then the speedo itself is likely the problem.