Faulty Fuel Gauge on 2001 Montana

Fred Klintworth
09-20-2006, 05:32 AM
The fuel gauge on my wife's 2001 Montana is no longer reliable. For example, it shows full when the tank is actually near empty.

I'm wondering how to troubleshoot the fuel gauge circuit. I'm wondering whether the problem is with the sensor (which I assume is in the fuel tank itself), the wires from there to the gauge, or with the gauge. My guess is that it's the sensor in the fuel tank. But, I wouldn't want to go to the trouble of replacing it (which I assume means dropping the fuel tank) without testing to determine it's faulty first. I have an ohmmeter and a handyman's knowledge of electrical testing.


09-22-2006, 11:44 AM
My 2000 Montana is doing the same thing. I talked to my trusted mechanic about it. He said this is not unusual, but that the sensor is integral with the in-tank fuel pump. Unless you want to spend considerable bucks replacing all of that, you'll want to wait until the pump dies. In the meantime, do as I do and just re-set the trip ODO at each fill up and keep an eye on total miles on the tank. I start looking for a gas pump after 400 miles.

Fred Klintworth
09-22-2006, 07:15 PM
SSuther: Thanks for the info. And guess what, we're doing the same thing you're doing. I told my wife 300 miles just to be on the safe side.:)

10-10-2006, 12:22 PM
I have heard (but haven't checked with the Chevy dealer) that you can now get the fuel level sender separately from the pump (around $100 if I recall correctly). Search the Venture forum and there are several threads about this - this (http://www.automotiveforums.com/vbulletin/showthread.php?t=226828) is a good one. You do have to drop the tank to replace the sender (or the pump), but it is apparently not that hard.

10-14-2006, 12:55 PM
Yes you can get the part, but here in Atlantic Canada it's about 280.00 , not worth it just keep an eye on the Miles and refill tank.

Fred Klintworth
10-14-2006, 03:27 PM

Thanks for the link to the earlier thread. After reading it I think I'll try a bottle of fuel system cleaner first; then, if I ever feel like it, drop the tank and try to repair (by cleaning) the sender unit. I don't think it's worth it to spend a hundred dollars or more for a new sender unit.

10-16-2006, 11:58 AM
After reading it I think I'll try a bottle of fuel system cleaner first;I have tried the new Techron (by Chevron) a couple times - it's supposed to keep fuel sender clean - but hasn't worked so far. I haven't tried anything mentioned in the other thread yet...

I don't think it's worth it to spend a hundred dollars or more for a new sender unit.Yeah, I'm the same way; our works fine until you get down to about 1/3 tank, so we just try to fill it at that point but keep an eye on the trip odometer too. At least for those that do want to replace the sender you don't have to buy the whole pump assembly any more!

10-19-2006, 06:48 PM
Had the same problem as you. If you look under the drivers side floor about 1 foot from the tank there is a plug that come through the floor. This is for the gauge. Unplug it and put the meter in the pin for the black/white and for the purple. It should give you a reading between 40 and 250 if it works right. 250 would be full 40 would be empty. IF you shack the vehical and it changes radically i would suspect teh sensor. However when i contacted my dealer they told me that the new pump/sensor comes with a new pig tale since they had problems with the old one. If your energetic you can drop the tank and check or do what i do. The compass and temperature computer in the roof also recoreds fuel consumption. This works off of the number of injector fires so it is independent of the fuel gauge. As long as you reset it everytime you get gas and recored how much fuel you add you can tell when your almost empty. However you may want to run a check once just to see how close it is. I found mine to be off by ~1.5 gallons. So i wouldnt run the tank down to anything less then 3 gallons. I like using this becouse i dont have to fill the tank every time i get gas.
Keep in mind this only works for gallons used not range. Range uses the level sensor.

Fred Klintworth
10-19-2006, 09:20 PM
sparky65: Thanks for describing a way to test the fuel sender. I'm going to try it. At least it should tell me whether the sender is the real problem.

One question about the location of the plug that comes through the floor. Is it under the driver's seat, the back seat first row, back seat rear row, or somewhere in between the seats?

Also, I don't think our Montana has a "compass and temperature sensor", or at least I don't know where it is if we do. Where is your's?

10-19-2006, 10:28 PM
I think the plug was under the back seat first row.
Your car may not have the compass and temperature sensor. It was an option. If you had it it there would be a small display directly above your inside review mirror, mounted to the underside of the roof in the roof consol.

Mechanic AD
01-21-2009, 08:55 PM
replacing the sending unit does not always fix this problem, just replaced it ($$$$), the gauge is still not working, we think the wires running from the tank to the gauge are corroded, they run under the carpets so are exposed to moisture. The computer also controls the gas gauge levels, and it could also be the source of this common problem!!

01-24-2009, 01:40 AM
Mechanic AD- Thank you for that info.This thread is over 2 years old. On AF we try not to resurrect threads that have been inactive over 3 months. In the future if you have new info to add to the discussion, please start a new thread and if you wish to, you may link to the old thread for continuity.

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