scootergmc

Bone stock '04 LX 1.7 MT
270k miles w/ routine maintenance.

Symptom: Tach bottoms out at 6-7k and reads up from there. Engine idles and runs normally. Just the tach is reading crazy high, but proportional.
If I turn key on/off, tach goes down a few hundred rpm, so after a dozen or so on/off key cycles tach is back to zero. This happened a couple of weeks ago, and it did it again tonight. The only commonality I can think of with both instances is my wife drove it both times the symptom arose.

I searched and found no answer. I'm thinking the car is finally starting to show its age. Any help? Thanks!

ezone

Sounds like the stepper motor for the tach might be losing its mind.

Try a cluster needle sweep test
https://www.civicforums.com/forums/p...382-post2.html



If all needles still don't sweep correctly, then try a battery reset. Disconnect both battery cables and touch them together for at least 5 minutes.
Then reconnect, start with positive cable first.

Start the engine, and check if gauges are right again. If good, do the idle relearn, unlock the radio. Drive it..

If not good, do the sweep test again....if still no good, then probably toss a cluster at it..

scootergmc

Thank you.


The problem reared its head again yesterday. Interestingly, the only correlation I can find between the (now three) incidents is that it the ambient temperature was high on those days (all near or over 100 F). This time it was stuck near 3k rpm. I did the gauge sweep (they swept) and it brought the tach down to 900, but did not fully reset to zero. I key flipped a couple times and now it's back to normal and working fine.

I suppose I could have a weak solder somewhere in the cluster that is affected by extreme temps.

scootergmc

Just to update, now the problem is pretty constant and I can hear the tach clicking during the gauge sweep. The fast faint clicking sound of the tach reminds me of the sound of a secondhand on an old wind up alarm clock.

Looks like the cluster may solve the problem, but at this point I don't know if it's worth it... Regardless, the mileage is stored in the computer and not the cluster, correct?

ezone

Mileage is stored in the cluster itself.

If you want the mileage in a replacement cluster to read the same as your original, you'd have to send the entire cluster to a speedo shop. The dealer scanner can't change the mileage in those units.
We use Palo Alto Speedometer.
http://www.paspeedo.com/

HTH

scootergmc

It does help, thanks. Looks like they do repairs as well.

seriba31

i got the same problem with my tach and speedo

scootergmc

I'm going to resurrect this from the dead as my speedometer finally took a dump as well. I figured I'd try the stepper motors first as it's cheap and nowhere near worth replacing a cluster, so I bought two replacement stepper motors from ebay for $10 total shipped. Soldered them in, now it's working good as new. Not a job for anyone who's scared of a small solder remove/replace job, but I've learned it's a common problem with these clusters, and the stepper motors were used in other makes/manf. as well.


edit: I should also add Palo Alto Speedometer does not repair these clusters, they only reprogram mileage. Now if you have a older European car, you're in luck.