RPM needles not accurate!
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Registered User
Joined: Sep 2011
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RPM needles not accurate!
i have an '06 - 4.7L and my rpm needle doesn't seem to be giving an accurate reading of what its really idling at. it will be idling fine in park, but my needle will drop all the way down to 0 rpms sometimes. sometimes when i first start it, the actual idle will stick around 1200 rpms for a couple seconds, then drop down to 500 or so. i cleaned the ICV lastnight with no change to the needle reading. so i guess i have 2 problems. my actual idle will sometimes stick around 1200 rpms, and also my rpm needle is not giving me an accurate reading. is there a way to fix the needle inaccuracy and idle stick?
Moderate User
Joined: Oct 2008
Posts: 17,003
Likes: 21
From: Albany, NY
You are either getting a bad reading from the pcm to the instrument cluster OR it is your instrument cluster that is the problem. If that's the case, then you need to replace your instrument cluster. For an automatic, i'd leave it be rather than spend money on an instrument cluster(although it's like $300 from the dealer brand new with your exact mileage)
You can go through the service manual in the FAQ section as it can guide you on how to check the wiring signals from the pcm to the cluster.
You can also do a guage sweep. I believe it goes like this....Press and hold thr trip button while you turn the key to the RUN position(DO Not Start) and then relase the trip button. Your guages will sweep one at a time. Watch your RPM needle as it sweeps. If it sticks or doesn't sweep then it's your cluster, if it sweeps perfect then it's your signal going to your cluster. I would reccomend doing this several times as it might not stick the first time if it is your cluster since the signal is strong and clear on those guage tests.
You can go through the service manual in the FAQ section as it can guide you on how to check the wiring signals from the pcm to the cluster.
You can also do a guage sweep. I believe it goes like this....Press and hold thr trip button while you turn the key to the RUN position(DO Not Start) and then relase the trip button. Your guages will sweep one at a time. Watch your RPM needle as it sweeps. If it sticks or doesn't sweep then it's your cluster, if it sweeps perfect then it's your signal going to your cluster. I would reccomend doing this several times as it might not stick the first time if it is your cluster since the signal is strong and clear on those guage tests.
Professional
Joined: Mar 2009
Posts: 151
Likes: 0
From: Manitoba, Canada
My truck does a similar thing, I believe its the stepper motor in the cluster. I plan on having a guy put a new one on my cluster. My brother knows this guy, apparently he's crazy smart about electronics like that...he used to diffuse bombs apparently!
Registered User
Joined: Sep 2011
Posts: 1
Likes: 0
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You can also do a guage sweep. I believe it goes like this....Press and hold thr trip button while you turn the key to the RUN position(DO Not Start) and then relase the trip button. Your guages will sweep one at a time. Watch your RPM needle as it sweeps. If it sticks or doesn't sweep then it's your cluster, if it sweeps perfect then it's your signal going to your cluster. I would reccomend doing this several times as it might not stick the first time if it is your cluster since the signal is strong and clear on those guage tests.
You can also do a guage sweep. I believe it goes like this....Press and hold thr trip button while you turn the key to the RUN position(DO Not Start) and then relase the trip button. Your guages will sweep one at a time. Watch your RPM needle as it sweeps. If it sticks or doesn't sweep then it's your cluster, if it sweeps perfect then it's your signal going to your cluster. I would reccomend doing this several times as it might not stick the first time if it is your cluster since the signal is strong and clear on those guage tests.
