Need guidance on the "speedometer stuck at 20" problem
 

I have a 96 Accord EX 6cyl. My speedometer sometimes gets stuck around 20mph (actually a little below, like at 18) and sometimes works fine. When it's stuck, the odometer also gets stuck. My cruise control works. I don't know whether I have a check engine light for this issue because my light is already on for a different problem and I haven't read the codes since this speedometer thing started.

My understanding from my searches is that this is almost certainly an issue with the speedometer and not the speed sensor. In this correct?

When I looked around a few days ago, I thought I found a site that said I just had to replace a board. During my further searching today though, it seems that most likely I have to replace the whole speedometer unit? That makes things more complicated because my mechanic is reluctant to deal with anything that might seem like odometer tampering (and I don't really like the idea of having a much higher or lower mileage showing either honestly).

If I do have to replace the gauge, can I replace it with one from an LX (no ABS) cluster? (I thought I had found one on eBay that is pretty close to my mileage, only 1000 or so over, though I can't find it now...)

Is this the sort of thing that a speedometer repair shop could fix? If so, what would the cost range be and how can I find one?

I suppose ideally I should buy a lower mileage one (likely to last longer before developing problems again?) and find a way to roll it forward? It's unclear to me though whether 1.) that's possible and 2.) the legality of rolling FORWARD... seems some think it might still be considered tampering?

Any suggestions/advice appreciated... I find myself confused about what to do because of the whole mileage issue. Thanks!

Re: Need guidance on the "speedometer stuck at 20" problem
 

Double check codes, but the fact the cruise ALWAYS (?) works, the spedo is bad.

As far as replacement/repair. That is going to be a matter of choice. There are hundreds of threads discussing the options, the FAQ even shows how to repiar.

Re: Need guidance on the "speedometer stuck at 20" problem
 

Thanks for the reply, poorman212! I can't really say ALWAYS on the cruise control, but I've tested it twice while the speedometer/odometer is NOT working and cruise control works fine.

I checked again in the FAQ and I can't find the speedometer repair thing. I did already read the cluster access and disassembly threads and found them very helpful and will be using them with whatever I decide to do. In fact the cluster disassembly thread is what made me think that there doesn't really seem to be a board on the speedometer that I can just replace without replacing the speedometer. But other than my one search result a few days ago (not sure which site it was) that I can't find now, I've found nothing indicating how to repair (or replace just the board), so a pointer would be much appreciated!

Re: Need guidance on the "speedometer stuck at 20" problem
 

So I went and checked the codes... nothing related to the VSS or speedometer (though there is a new O2 sensor code that I didn't know about, so glad I checked).

I also found some of the threads talking about resoldering or replacing just a board (though I still haven't found the guide you mentioned). This had me feeling a lot more confident about my original "replace just the board" plan. Except...

I also found threads talking about how for some people, hitting the trip reset while moving at a reasonable speed made everything start working. I tested it (just twice so far) and this seems to work for me when I'm going above 20mph. So this has me thinking again that it's unlikely to be a solder joint/electrical issue and more likely to be a mechanical issue that does require replacing the whole speedometer, so now I'm confused again. Can anybody for whom the trip reset temp fix worked comment on whether a board-only replacement worked for them?

Edit: I'm not sure about the speed correlation on the "trip reset" trick working anymore

Thanks!

Re: Need guidance on the "speedometer stuck at 20" problem
 

Another question: if i'm only replacing the board, does it matter if i get a HR-0186 version or a HR-0187 version? (apparently there's 2 different cluster depths? i hadn't seen anything about it here yet)

Re: Need guidance on the "speedometer stuck at 20" problem
 

for future reference of anyone reading the thread, replacing just the board fixed it for me, though i managed to burn out a cluster bulb in the process. the old board looks fine on visual inspection. (in fact, without any prior knowledge of working condition i would have rated the new board less likely to work... the solder joints looked less solid -- were dimpled, etc.)

Re: Need guidance on the "speedometer stuck at 20" problem
 

With circuit boards it's difficult to see with the naked eye. Always test before swapping. An alternative is getting a junk cluster and swap the speedo into other cluster. That still doesn't guarantee it will work.

Re: Need guidance on the "speedometer stuck at 20" problem
 

Most of the time when you don't have any DTC's related to the VSS you've got a PC board problem. I'm a electronics repair and Honda/Acura service tech in NC and I can fix your speedo PC board for $90.00. You can buy used but there's no guarantee that it will be in any better shape as yours since this is a common problem with these cars. Keep your current gauge and mileage and have your PC board repaired. I can have it back to you within a week. I can tell you that on this particular model just touching up the solder joints will not repair anything, it's a problem with a failed component on the PC board.

Re: Need guidance on the "speedometer stuck at 20" problem
 

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))

Re: Need guidance on the "speedometer stuck at 20" problem
 

PSM321...so what do you mean when you say "you replaced the board"?