Little tach problem
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Joined: May 2002
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From: Aurora, Ontario
Little tach problem
Hey guys I just noticed this the other day on my truck. When Idling the tach bounses up and down about 1/8". Is that normal for these trucks mine is brand new got less then 22,000 KM/h On it. it also does it when in cruise.<br><br>Jamie
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Joined: Jun 2002
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From: Winder, GA
Re:Little tach problem
I haven't traced the problem yet but my tach will completely stop working for a few minutes than start working again and be working perfect. No jumping or anything. Then it'll half *** work.. then die. etc
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From: St. Louis, MO
Re:Little tach problem
Jamie,<br>The movement of the tach is normal. It has probably done it since you bought the truck and just never noticed in before. It has to do with the ecm reading the crankshaft position sensor and updating the tach. I think that everyone's truck does it to some extent. I wouldn't worry about it.
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Joined: May 2002
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From: Sandy, Utah
Re:Little tach problem
You are correct sir.<br><br>The tach is electronic and gets its info from a sensor.<br><br>The electrons are getting confused.<br><br>Poor PCM or ECM (whichever controlls it) is overwhelmed with information and can't keep up with everything in a timely fashion, so the Tach jumps around as it gets info a little late.<br><br>My 2002 has done it from day one.<br><br>If not for this board, I would have worried a bit about it as well, still did anyway.<br><br>phox
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Re:Little tach problem
[quote author=Superduty12v link=board=7;threadid=5632;start=0#49483 date=1034014129]<br>I haven't traced the problem yet but my tach will completely stop working for a few minutes than start working again and be working perfect. No jumping or anything. Then it'll half *** work.. then die. etc <br>[/quote]<br><br>mine did the same thing and I had to replace the crankshaft position sensor and mine has not had that problem since.<br><br>check in the articles and then click on the "tech articles" and I show how to replace this sensor pics and details.<br>Ricki
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Re:Little tach problem
Hey superduty<br> here is the link to that "how to", it was done on my 99' but may be same as yours, if not then it may give you an idea.<br><br>http://www.dodge-diesel.org/articles/cps/ckp.htm<br><br>Ricki
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Joined: Sep 2002
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From: Palmer Alaska
Re:Little tach problem
IF THIS DOES HAPPEN TO OUR TACH'S RIGHT NOW, WILL IT EVENTUALLY GO BAD LIKE YOURS? I WONDER IF DODGE WILL REPLACE NOW? AND WILL THE PROBLEM GO AWAY? MY TACH JUMPS ALL THE TIME.
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Joined: Nov 2001
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From: Austria Europe
Re:Little tach problem
It depends on how high the tach jumps. If it's just about half way between the marks its normal. The electronic tach just has this many positions. If rpm falls a little (something like 1-10 rpm) when the tach was on the low end of the segment you'll see a jump. <br>If it fails completely for some seconds or so I'd suggest to check the cluster (Self test depending on model year) and look for bad connections. Sometimes a bit of contact cleaner and dielectric grease goes a long way<br><br>HTH<br><br>AlpineRAM
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