OK, here's something (like you need more advice from me ) It seems there is a "test mode" for the combination meter (cluster). I've copied the instructions below but all your service manuals are here (thanks to NICO club again):
http://www.nicoclub.com/FSM/G35/Sedan/2005_G35_Sedan/
and this is from the file "di.pdf ", Driver Information System.

 

Did the testing with the gauge, the FSM states it should look exactly like the picture.

Picture shows gas at half. This obviously isn't half, close but not half.

 

Man!!! That's sucks...sorry to hear it! I'm leaning to the cluster. My only experience with cluster is on a 2004 GMC YukonXL I have. I pulled it out and sent it to be repaired which worked. Wish I knew more... wish my G was working!!! Keep us posted if ya would! Tks!!!

 

Been having the same issue with my fuel level bouncing around and haven't replaced anything yet. I did clean the sensors on both sides and it didn't help. Just went out and performed that self diagnosis that u performed turtle and my fuel level is in the same area where urs is. It would be cool if someone without a fuel gauge issue could perform this test and let us know there results. Im hoping its a sensor issue and not the cluster. Keep us updated with any new info turtle!

 

I just bought my 03 G35X and found the I have the same problem with the gauge. It will not go pass 3/4 or below 1/4 so I took out the fuel unit on the passenger side and found that the fuel level sensor was not attached to the unit. It was just hanging by the wire. I popped it back in and fit everything up this morning and what do you know...the gauge is reading above 3/4 now since I out $60 worth if gas last night! Don't know if everyone else will have the same luck but it's worth checking out that fuel level sensor first. It's the most logical and easy thing to do.

 

Yeah... did that first thing. I believe all who have this issue have pulled both the fuel level sensor and the pump with the sensor. Turtle even replaced both units but no love for him. Tks for feedback, glad yours is working!!

 

Here is an update for me, I took my car into Riverside Infiniti, and that afternoon they told me that the sender units were reading perfect, it was the fuel gauge that is broken... The fix you ask? A brand new gauge cluster... A $1200 part that is back ordered with no ETA when it will be available... Thank god for my extended warranty....

 

Please let us know if the gauge fixes the problem. I thought mine was fixed after my gauge worked after driving about 25 miles. Now I'm back to square one (gauge does not go below 3/4. SMDH...

 

Did anyone ever figure out what the problem is here? Is it the cluster?

I had both sending units replaced, and I still have this problem (won't go below half tank).

Thanks!

Josh

 

One person messaged me with the same issues, he got his cluster repaired for like $200. So far so good.

Mines has been working in the cold like 25% of the time compared to 5% in the warmer months.

 

TurTLe... you still have same prob? I've just been dealing with it but sure would smile more if fuel gauge worked correctly. Can the instrument cluster be pulled as a whole and repaired? Tks for your feedback!! -r

 

What about if my fuel gauge light is dimmed ???

 

Nothing more on this? My gas when it hits 1/4th tank it starts rising to like 3/4. After I let it sit and turn on it shows me what im at then rises as I drive!!!

 

I just bought my G three weeks ago now and have the same problem. It rattles me bad that this is happening. Mine goes up and down a little also. Since replacing the sending unit doesn't seem to work I want to see if the cluster replacement is the answer before I buy one.

 

So it seems that a repair or replacement of the cluster is the solution. A google search shows a few places repair for $125 - $180. If you tested both sender units - and performed the test SkylineSedan took time to show/link... cluster fix seems to be cost effective solution. I had it done on a Yukon I own about 3 years ago. Complete cure of my gauge probs. Keep us posted on things.