everytime i start my engine, my speedometer goes up then down to 20mph, when i drive around slow it moves a lil bit up and down and when im doing 30mph above it doesnt move. and becuase of that the mileage on the car doesnt work also. i have a 1999 honda civic EX with d15b engine and an obd2 p2p ECU.

i just bought the car, 2 weeks ago or so im kinda new to this thing

 

why does your 99 EX have a D15B in it? Shouldn't it have a D16y8? And check your speedsensor and plug. its right next to the T bracket in the back, rectangle plug with 3 wires.

 

speedometer head is dead. either resolder the joints on the back of it, or just buy another one off ebay. just did mine and put a crv cluster into my ek hatchie

 

it was swapped by the previous owner.

 

sorry for double posting. this is to respond 92lxsleeper's comment, actually it works(sometimes), when im flooring the throttle it works.

 

could still be bad. mine worked intermittently. work for a few minutes, then die. sometimes it woudl work for a full day others not. check all the wires first, especially under the intake manifold. its possible the rubbed through the insulation, but i still think the speedo head is bad.

 

after searching, i failed finding the vss underhood. can anyone post a picture where i should look? please?

NVM i found it.

 

passenger side on the transmission under the intake tube.

 

my vss female relay has a green thing on it. somekind of fungi or cement thingy. on the black wire. took out the vss itself and they're good, gear is in very good condition. how do i clean the female relay? and what if the wiring is damaged? how do i know if the wiring is damaged?

 

Use a multimeter to check if the wiring is good. You can try using a q-tip with rubbing alcohol on the harness, dont use too much alcohol.

 

ok thank you.

 

Is code 17 thrown?

 

question... does it go up to 20... once the ignition is turn on, but not started yet? Like... where the fuel pump primes and the srs, cel lights will go on and go off... Or is it only when you start the car?

 

@RonJ@HT no i havent checked the code cause the last time we checked it, it doesnt throw any code. my CEL was probably because of my vtec and knock sensor since im using a d15b engine on an obd2 p2p ecu.

@Mfoehrkolb Only when engine is running.

 

Check for codes again.

 

--- So your code goes away when you shut the car off and back on?
Does it come on after driving for a little bit?


You are absolutely sure... The speedo doesn't move before the engine is actually started?

 

https://www.youtube.com/watch?v=8lIEGaWfi4Y

https://www.youtube.com/watch?v=veCGzntRC2g


I know it's not exact, but as soon as the rpms would change, it shoots to 20mph and then went erratic.

(dont mind the white faced gauges, those were promptly removed and put back to oem classiness)

 

ok when engine is not running(ignition on II) speedo goes to 20mph and as soon as i start the engine speedo it wiggles between 18-25 when i accelerate slow, and when i reach 20mph above speedo stick stucks at 20mph.

 

--- Okay, how about when you are definitely doing faster than 20mph? Does it begin to go up?

 

nope, only when i beat the car up. flooring the pedal, and/or doing a fast turn. dont know what exactly i did but that was the time i remember i was doin when it worked.

 

--- Well, you clearly have a wiring issue. 95% of the time... It's corrosion and or broken pins on the harness/speed sensor. Corrosion>BrokenPins though.

My experience with the 4 hondas i dealt with that had VSS problems was... Corrosion, corrosion, Broken pin, and broken pin.

Corrosion you can clean with electric clean (i used carb cleaner cause its what i had but it messes up plastic but im a rebel), wire brush, sand paper if you can fit it... Anything to just resurface the connection.

Start with the spray to clean out any gunk and or water that is sitting in there. Then clean the connections, on BOTH VSS and harness that is corresponding with the VSS.

Visually check the harness plug and wiring for visible damage such as breaks, cuts, or fraying. Throw a piece of electrical tape around it just for the heck of it even.

MAKE SURE YOU RESURFACE THE CONTACTS WELL! don't rush it.

Plug it in and drive.

the only reason i can see your speedo being off besides for the VSS being messed up is that, someone had your cluster apart and removed the mph needle when performing some action that requires you to remove the pin... (doesnt matter but, putting white face gauges on, rolling back odometers, changing the needle etc)

My bet is the corrosion or the pin/wiring.

 

it has the white face gauges on. ok thank you Mfoehrkolb ill clean it this weekend.

 

--- Idk the size of your needles off hand and or the type of white face gauge inlays that are being used (they are just a cover than peels off). The installer of them might have been able to actually slip the gauge cover over the needle and then screw it/stick it down.

OR...

Since you have white face gauges... It could be a combination of both being your problem.. Such as your gauge going to 20mph because it wasn't calibrated correctly after the needle was removed, and the VSS could be acting up simply because of the wiring/corrosion issue at hand.

 

i did thought it was because of the gauges but yes it was just a slip on thing. i tried to take it out thinking it was causing the problem but dint fix it so i slipped it back in. ill check in the weekends for the wiring issue, it was hard getting the wire separate from the VSS that stick inside the transmission. so i guess the corrosion is a thing too. thank you!

 

--- remove the intake arm and you should be able to reach down and unplug it. Might just be difficult because of the location and finger strength requires to punch the tab. the hardest part will be cleaning the harness if you can't get it close to you. You will simply have to go "***** deep" in the engine bay and get comfy lol. As i stated before, take your time and do it once.

If you were the installer of the white face gauges, and you didnt remove the needle... You are fine then with the needle calibration. Also, as long as it didn't jump up to 20mph always since you purchased it from the previous owner.

That "stick" inside the trans IS the VSS... you can remove that with the 1 10mm bolt (maybe 12 i dont remember) holding it in place. Wiggle it around and tug on it. Should pop out. Make sure no debris falls into the transmission though.