Hi All-

Fuel gauge stays on Full and beyond. I believe I need to do the fuel level sensor replacement.

First I've filled the tank and added two bottles of the Techron fuel cleaner to see if that affects the gauge. I assume it won't but worth the try. I've read allot on the replacement but I have not read of any ones gauge that stays in the full range as mine, all I see is that the gauges end up at empty. So, I'm wondering if that has any diagnostic value?

Also, I've read where people have done the pump/fuel level sensor replacement and find it's a faulty "stepper motor" instead. Is there any way to check if the stepper motor is at fault here?

2005 TB EXT LS 4WD 6cyl

Thanks for your comments,
Robes

 

professionals check the stepper motor by doing a cluster sweep test of the gauge needle. a working stepper motor will sweep to the full position and back to empty. If the needle is pointing beyond the normal sweep...the stepper motor is nfg.
a faulty sending unit will not send the needle out of its working range of min to max.


post a pic of the where the needle is resting

 

I just filled the tank to run the Techron fuel system cleaner, the gauge read slightly over the "F" full mark and took 10.5 gallons. Here are two pics with the full tank of gas. With the truck NOT running see the gauge reading Full. With the truck RUNNING see the gauge WELL OVER FULL.






UPDATE:
I have driven the TB 38 miles today on the mentioned full tank of gas. Running, the gauge reads about a 1/4 tank over the full mark and shut off the gauge reads between a 1/4 and 1/2 tank now. Maybe the Techron is starting to do something? It's been about 20 hours since the tank was filled and the 2 bottles of Techron added.

 

you need a stepper motor

 

Thanks for the replies everyone. I also posted on TrailVoy and all agree it's a stepper motor. Well, I need to search on that now, learn about it and how to install.
Robes-

 

Hi, Tanin Auto Electronix here. We are vendors on the site and specialize in cluster repairs as well as sell DIY parts like stepper motors.

If you prefer to send the cluster to us, we can run the diagnostics and do repairs. Here is the link for our service:

Gauge Cluster Speedometer Diagnosis Service

Otherwise, if you want to do the install, here is the link to our stepper motors which are very competitively priced :

GM Switec X27.168 Stepper Motor

Let us know if you have any questions at all. We are happy to help out any way we can.

Thanks,

 

those prices are the best I've seen.

 

I would check for a recall on that gauge problem. I vaguely remember on my 2002 TB having a recall on that problem with the gauge pinning. Won't hurt to check.
Good luck.

 

I called GM and the TB is no longer eligible for any of the extended warranties being it's in service date was Oct of 2014. Well past the 10 years, and that's it.

I'm down to about a 1/4 tank from the initial full tank + 2 bottles of Techron I put in it. The gauge has been functioning normally since yesterday, I'm still watching it and plan to refill again checking levels. I won't know till I finish another full tank if it is truly working again. Could be the Techron is doing something, but if so, I doubt it will last long....We'll see-
Robes

 

Hello All-

Here is my story to date. I filled tank and added 2 bottles of Techron on 3/12/16 and after driving 38 miles that day I noticed the gauge beginning to act differently see (3/12/16 Update bottom of pics posted).

On 3/15/16 (3 days after adding Techron and still using the fuel with the additive) the tank seems like it could be reading actual levels, but couldn't be positive. Although, when shut off it read empty and when running went up to 1/4 tank which is what I thought might be correct.

On 3/20/16 ( 8 days after 2 bottles of Techron added to full tank) I refilled the tank with gas only. The gauge has been working perfectly up to this posting date (4/3/16), a total of 19 days since I thought it was reading correctly.

It's possible allowing the gauge to be in contact with the treated fuel as long as possible may help dissolve deposits which cause the malfunction. I will probably treat again when I know the TB will be sitting for a number of days just for good measure, but only add a single bottle- it's not cheap.