tom_704

So here is my issue. My speedometer is stuck at about 20mph and while it is stuck my odometer will not work. At times the speedometer will randomly start working making the odometer work also. I drive a 96 Honda Accord DX 2.2 with 156K on it. So guys what do you think I should take on first the VSS or should I start messing around with the speedometer cluster.

P_Adams

This doesn't have any aftermarket gauge faces on it?

Try pushing in the odometer reset stem and let it snap back out.
The mechanism of which this stem controls will sometimes not re-engage correctly.
If that doesn't take care of it, it's most likely internal to the Cluster Assembly.
The VSS will either supply a signal or won't. No partial signals. It either works or it doesn't. (and it would most certainly set a lamp if it were malfunctioning)

P

tom_704

no the car is all stock. The only thing aftermarket it the CD player.

thehondaguru

Sorry to bring this post up, but I am having the exact same problem on my 99 CL 3.0.

Shoudl I just change the cluster, or is there a way to fix it internally.

Or, if I do change it how tdo I go about getting my mileage correct?

bseriescrxsi

that gen accord had a big problem witht he boards inside of the cluster itself...it is a diy job....but you must take the dash apart and get the cluster out...replace the main board and the small board on the back of the speedo/odo unit....

thehondaguru

Which boards exactly? Shoudl I just buy a whole unit on ebay and tear them apart? CAn you show on a parts break down what boards are causeing it? Thanks for the info..

Targa250R

If the Check Engine light is coming on whenever the speedo/odo unit stops working, then the problem is with the VSS in the transmission or related connectors/wiring.

If the Check Engine light does not come on, then the problem is in the speedometer head itself - someone apparently determined at some point that it was caused by dry solder joints on the circuit board behind the speedo. If you can't solder, then your best bet would be to just buy a used gauge cluster from another '94-97 Accord and swap it in.

thehondaguru

No CEL, and my cruise works, so I figured it was the speedo unit.

I can solder, so where do I look for the problem?

thehondaguru

Well I took the speedometer out, and resoldered everything on the circuit boards, and its still broken.

I just ordered a new cluster, how do I change the circuit boards only? I want to do this so I can keep my odometer mileage correct.

I hav enot been driving the car because I don't want odometer problems tagged to my vin#. Or, how to I roll the new clusters mileage forward to match my cars?

thehondaguru

Anyone????

blue95

On the back of the cluster there are 4 gold colored screws that hold the speedometer. Remove the screws, unclip the bezel, and lift the cluster off of the bezel; you will see the back of the speedometer laying in the bezel with the circuit board facing you. The only thing holding the board to the speedometer assembly is a few pins; just lift it off and replace with the board from the new cluster. Reassemble.

thehondaguru

OK sweet. I had it apart, I just didnt want to pull the circuit board off. THANKS!

thehondaguru

Whoops!

TOOLMAN1966

I had the Speedometer indicating 20mph and Odometer not working problem, half the time. The other half it worked perfectly. Mine is a 1998 Civic EX. My problem was a broken solder connection (often called a "cold solder joint") on IC1 pin 10. My circuit board is the one pictured by REVOAPPAREL in this thread on 8-15-2012. This pin is one of the epoxy (or glued) pins. I used the soldering iron to remove this epoxy from the pin before re-soldering it. (The heat kind of crumples the epoxy so it can be scraped off with the iron tip.) The Vehicle Speed Sensor signal comes into IC1 on this pin, but also on IC1 pin 12, and IC2 pins 10 and 15. __ I found which solder connection was broken in the following manner: Removed the circuit board from the speedometer/odometer mechanism (it pulls right off.) Attached a 12 volt power supply to IGN and GND. Used a voltmeter to read COS & SIN voltages. These 2 voltages tell the speedometer needle where to point. (RED voltmeter lead on COS+ and BLACK voltmeter lead on COS-.) (Don't look at the voltages with respect to GND. The speedometer doesn't see that.) When the circuit board was working correctly, the COS voltage was 5.04 and the SIN voltage was 0.26. These are logic levels ONE and ZERO. (If you remember your Trigonometry, the COS of zero is ONE and the SIN of zero is ZERO. Zero is the vehicle speed.) When the circuit board wasn't working correctly (this is when the needle would indicate 20mph IF it was attached) COS voltage was 2.47 and SIN voltage was 1.80. When I read these WRONG voltages, I started touching things and when I pushed on IC1 the voltages became correct for a moment. Then I used a probe to push against each IC1 pin individually and found pin 10 was the pin not making contact. __ A person should be able to use this technique to find a bad solder joint anywhere on the board causing incorrect speedometer readings when the vehicle is sitting still. ___ I also traced out the entire circuit board and drew a schematic. If I figure out how to post a scanned pdf of this, I'll attach it. ___This is my first post to any automotive thread. I sincerely hope this helps many of you out with your speedometer indicating 20mph problems! Enjoy Troubleshooting! ((Toolman1966 _ APRIL 14, 2013))

Rudy543us

Hello,

I have the same issue, my speedo stays at 20 mph. What is the exact name for the circuit inside the speedometer assembly I need to replace.

Thank you

1chris311

I've got a 1998 Honda civic ex coupe that's been doing the same thing. I've checked the vss and with it unplugged the speedometer still jumps to 20. I tried pushing the trip reset button and letting it snap back like you said and that does seam to temporarily fix the speedometer but after a min or so it quits working. How can I fix this? Thanks

BeastlyB

Does it have a a maintenance reset button? A little slot on the dash where you have to stick the key in... If so try that it worked for my Odometer.

1chris311

Tried it. Didn't work. 😭

1chris311

that was way over my head! I need pictures!

booboo782

I had this very same thing happen to me, and it has slowly gotten worse over the months; intermittent speedometer cutting to 20mph at freeway speeds, then back to normal. I have just been dealing with it, but finally got sick of it and found this thread, and wanted to expand on the subject. In my case it was NOT the VSS as my logging program was reading correct speeds from the ECU. My car is a regular old 98 EK coupe with OEM cluster. I suspect others that are having this problem can benefit from this writeup, and it will probably work on EGs and who knows what else that exhibits the same behavior, feel free to add to, and chime in on this.

I decided to distill the info from TOOLMAN1966 above and dive in and give it a try. Here is a little more description for the fix:

1) Remove cluster from dash and gently separate the lens from the base to gain access to the guages.

2) Unscrew 4 phillips screws from the back center of the housing to release the speedometer pod.

3) GENTLY seperate the circuit board from the back of the speedometer pod. This will take some fiddling. Don't worry, it comes off; you will see little pins that connect the board to the hardware.

4) On the board you will find a chip labeled "IC1" (see pics). The pins that stick through the board to the green side are the pins in question. Apparently the factory did a soldering job that was just good enough to not bother anybody for 17 years, sadly there is a "cold flowed" pin on that IC1 chip, and the solder must be reflowed to proper temp to make better contact and fix this. On pins #1-12 I used a heat gun for a FEW SECONDS to heat up that gunky resin you see globbed on there by the factory and gently scraped it away. Then just go down the line with a hot soldering iron and heat each pin (just go ahead and do all #1-24 while you are at it) making sure they reflow correctly, but you DONT want the pins flowing together with each other. This will ruin your day. Also just be careful in general as you can easily ruin this little board between scraping and soldering and whatnot.

This process did the trick and all has been well since! Speedometer is reading fully normally. Hope this helps someone else out to understand why we are having this issue on our older civics. Factory error plain and simple that only shows up 17 years or more in the future.

denierlexiese

Just an idea, if we didn't have inpsecitions in Texas I wouldn't have fixed the speedometer on my accord. [the spedeometer sensor just went out - $80 fix at autozon] I would just have used my android phone mounted to the windshield. It shows an accurate speed in real time if it has a gps unit built in.

touring2

my speedo developed this problem, and I replaced the VSS, no joy. but thanks to this excellent post, I'm on the track I dreaded before. I don't know if I'll be able to do the whole trig thing, but thanks, toolman.

touring2

thanks to booboo782 for the perfectly timed pictures in this old thread. I just got the "20 mph" on our 95. And thanks to Lupe Cervantes over on the YT for "94-97 Honda Accord gauge cluster removal also stereo". very helpful

BeastlyB

Excellent write up and photo's

chris89

+10 for everyone who helped.

This can be fixed without buying anything. Except tin foil. I took out the speedo pcb, wraped the top part with the chips and cap in tin foil (add extra 3 layers on capacitor) left bottom solder points open for re-flow. Make 4 tin foil ***** to lift the pcb off the cookie sheet. Pre heated over to 450f, 15min at 450f don't touch it at 15min open door and leave to cool. Re-install should be good to go. This has worked and especially on the ECU, it was a complete and utter fix for my ECU.

FYI - I have years of trial and error on what temp/ time combo is perfect and found 450F at 15min exactly does it every time. If you have temp error on your oven leave for 25min.