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1999 Tahoe Gas Guage Failure


bscheper
01-28-2009, 11:50 AM
I have searched the Tahoe and Suburban Forum and found many threads about flickering and incorrect fuel guages however I did not find one that had a result for the flickering guage. My 99 2wd Tahoe had a flickering gauge for a couple years, now it is irradic and won't give an accurate reading. It has even spun in circles at times. Does anyone have a resolution?

j cAT
01-28-2009, 03:21 PM
I have searched the Tahoe and Suburban Forum and found many threads about flickering and incorrect fuel guages however I did not find one that had a result for the flickering guage. My 99 2wd Tahoe had a flickering gauge for a couple years, now it is irradic and won't give an accurate reading. It has even spun in circles at times. Does anyone have a resolution?

I don't know or heard anything about flickering gauges....the problem is erradic readings from full to emtpy...when full gauge reads empty when empty guage reads full...and everything in between....


the other more difficult problem is when the gauge vibrates at a high rate...if this is your problem it USUALLY means a bad instrument panel...

roadrunner2
01-28-2009, 04:44 PM
When the gas gauge acts up like that, the only cure is to drop the fuel tank and replace the fuel sending unit.

NoEcm
01-28-2009, 10:31 PM
You might want to do a search on some of the forums for "stepper motor".

Want a laugh, check this out:
http://s285.photobucket.com/albums/ll47/usmc6213/?action=view&current=Video-0002.flv

NoEcm
01-28-2009, 10:33 PM
Here's another one:
http://s80.photobucket.com/albums/j161/Snoopfizzle_photos/?action=view&current=002-4.flv

j cAT
01-29-2009, 09:56 AM
Here's another one:
http://s80.photobucket.com/albums/j161/Snoopfizzle_photos/?action=view&current=002-4.flv


these problems would be not that hard to find solutions if the electronics where made available to repair/troubleshoot..ITS ALL TOP SECRET..

bscheper
01-29-2009, 12:33 PM
The first video above is exactly what mine is doing today (spinning in circles). It is interesting that after searching the posts there seems to be many theories on the solution. 1.) Those that state to replace the sending unit and that is the problem. 2.) Those that state a bad sending unit is a sign that the pump is going bad also. 3.) Those that have replaced the pump and sending unit and are upset that they spent the money and it didn't fix the problem. 4.) Those that state the ground connection may be the issue. (have not read if anyone has fixed the ground connection and the solution worked. would be interesting to know) I love my tahoe and I can't expect much since it has 182,000 miles on it but the spinning guage is driving me nuts and not to mention screwing with my oil guage. I will crawl under it asap and check the easy ground solution first and will let you know just as soon as this snow and ice clears.

j cAT
01-29-2009, 02:05 PM
the fuel level sender is a variable resistor, as the fuel level changes the current flow changes this is then how the pcm determines the level..

when the tank is full the current flow drops ,, high resistance..the voltage supplied by the pcm is 5 volts...the return ground is at the pcm.. so internally the pcm then sends a voltage to the dash fuel level sender....because this is a low voltage low current signal any poor grounds or connector corrosion can mess this up...you may remove and reinstall these connectors then find it works ....but which one was the problem????

check connectors at pcm C1 and C2 as C2-54 is the 5volt and C1-80 is the ground connector..

still though it can be the dash unit ,,,connectors to that etc...

handyandy60
11-25-2009, 10:10 AM
You might want to do a search on some of the forums for "stepper motor".

Want a laugh, check this out:
http://s285.photobucket.com/albums/ll47/usmc6213/?action=view&current=Video-0002.flv
You don't need a mechanic. You need an Exorcist !!!:lol:

bowhuntrrl
11-28-2009, 01:06 PM
I just replaced the pump and sender on my '98 Tahoe. I still am experiencing the same fuel gauge problems that I had. When I fill it, it goes way up beyond the "F" mark. Then when I have only used 20 out of the 30 gallons that my tank holds, the gauge goes down below the empty mark. Does this sound like a ground problem as mentioned here or the dash unit ?? Sorry if this seems like a hijack, I just thought that since the thread was open and had some similarity that I might get an answer here.

j cAT
11-28-2009, 04:13 PM
I just replaced the pump and sender on my '98 Tahoe. I still am experiencing the same fuel gauge problems that I had. When I fill it, it goes way up beyond the "F" mark. Then when I have only used 20 out of the 30 gallons that my tank holds, the gauge goes down below the empty mark. Does this sound like a ground problem as mentioned here or the dash unit ?? Sorry if this seems like a hijack, I just thought that since the thread was open and had some similarity that I might get an answer here.

when the fuel tank pickup resistor gets dirty/film on it this causes the fuel gauge to read random amounts of fuel levels.

my gauge has been doing this for many years now.

since you have a failure that is a constant repeating failure to correctly read the fuel level ..I would say it could be in the dash...

I have not yet had reports of success with some of these weird fuel gauge issues.


try inspecting the pcm/ computer connectors make sure they are clean bright metal pins no green colored ..

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