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Randall C
Randall C, ASE Certified Technician
Category: Toyota
Satisfied Customers: 12803
Experience:  ASE Master Technician, 32 years, diagnostic/repair / electrical specialist
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Tundra SR5 access cab: Hi I have a 2003 Tundra, SR5 access

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I have a 2003 Tundra, SR5 access cab, V8.

The truck has had a "lazy" fuel gauge since I've owned it (i.e. after fill ups the gauge slowly reads full). Lately though the gauge seems to bounce between the half tank indicator and full then back again. I thought I was going crazy, I mean the truck is a pig on fuel but I thought wow, never that bad. lol

Is this the sending unit starting to go south? Is this part of the fuel pump? If so how do I go about replacing it? What are the Toyota part numbers of the sending unit and rule pump assembly?

Hello, I am Randall. I will do my best to answer your question
the only way to test the sender is to drop[ the tank, unplug sender and probe with meter working the arm up/down and watching resistance on a meter. Or have to locate the yellow./red wire and the brown wire and hook meter between those 2 wire in the harness going to the pump and then, have to test at different fule levels but this mthod is very time consuming
Likely the sender is bad. It is sold separate and the part 3 is below
This requires dropping the tank whereas there are no directions for this other than the diagram in which you wait till gas near empty, undo the hoses to the tank, The jack under tank and undo straps, Lower down some and disconnect the fule lines and remainingh hoses and elctricla plug to the pump. The pump is them unscrewed from the top of the tank and lifted out and ender is changed. Something has happened to the float

Special fule line disconnect tool is needed to remove the lines but can buy cheap at most any parts store

Part #(NNN) NNN-NNNNbr/>

Customer: replied 3 years ago.

I thought so, ugh!


Looks like one of those, as long as you have it all a part you may as well replace the fuel pump too. lol.


After reviewing your procedures I thought; wouldn't it be easier to remove the truck bed to gain access to the top side tank components?

you know, we get that question as well as some customers cut a hole:) the bed is not my specialty as body work stuff but in some cases may be easier. In the shop, on lift, low gas, dropping tank goes fast. yes,, you are 100%. drop tank? do the pump if in the budget
Customer: replied 3 years ago.

I bet you do get asked that quite frequently.


Unfortunately I don't have a lift in my garage (but I sure would like one).


I recently had the bed lined so the mounting bolts are exposed and rust free. So I figure disconnecting the fuel filler, unbolt the bed, slide or lift it out of the way and perform the tank work.


Thanks for the help!

yes, it will, great idea, yes,, you undo the fule FILLER neck from bed then slide or remove. All you are doing is access to top of the tank. 1.8 hours book time and lowering tank. Lowering with near empty is easy on the ground, Bad when we get them full
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