My fuel pump diagnostic and repair thread

Never became an issue until recently. The more I looked, the more prevalent the problem was on the Tundra (and a lot of other Toyota models as well). This is my attempt at diagnostic and repairs. Please feel free to give any suggestions.
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I own a 2016 Tundra 5.7 non-flex fuel.

Emissions code 3UR-FE = non-flex fuel

On April 22, 2022, with no warning and 30,369 miles on the clock, the truck would crank but not start.

I found a lot of videos on youtube about this problem, and a lot of them show trucks with surprisingly low mileage.

This one helped me the most: (153) TOYOTA TUNDRA CRANKS BUT NO START - YouTube

I came back on April 24, 2022 (had to travel for an event) and tried cranking it again. It fired briefly but died. I figured it was because I had filled a full tank before I parked it, and the fuel expanded just enough to give it a slight amount of fuel pressure, but then nothing.

The first thing I did was scan codes with a generic OBD-II scanner: no codes! I don't have Techstream so I don't know if that would reveal anything.

I had a full tank of gas so I knew lack of gas wasn't the issue.

I put my hand on the fuel pump lid while someone cycled the key. Nothing.

The next step is fairly dangerous, and I don't recommend anyone doing this. I was 99% sure the pump has failed.

At 5:00 in the video I posted, they pulled the high fuel line on the fuel rail. I don't like doing this because if the pump were working, you would be shooting fuel straight onto the exhaust.

Before dropping the tank, I did my due diligence and verified with the dealer. The fuel pump recall doesn't cover 2016 model year, and I didn't buy the extended warranty.

Given that I don't offroad or mod, my use is limited to going to Home Depot and taking trash to the dump. I drive less than 5,000 miles a year. With my experience with Toyota, there was no reason to get the extended warranty at the time.

Now, I would definitely buy the 10-year warranty.

For the next step, member Viktor G was instrumental. He even responded to my stupid questions.
(153) 2007-2021 Toyota Tundra Fuel Pump Replacement Instructions - YouTube

This video also helped me because it shows how to remove the charcoal canister connection (Viktor G doesn't run a canister, but he does explain how the connector is removed).
(153) How To Replace Fuel Pump 2007-Present Toyota Tundra - YouTube


Screen grab from Viktor G's video at 0:26. I removed the high-pressure line from the pump (the red connector).

The proper way is to hook the red connector to a 3/8" barb, then to a fuel pressure gauge, and then run the gauge to the 3/8" hard line.

But I was fairly convinced that my fuel pump has died so I just left the high-pressure line disconnected. I cycled the key and cranked several times, but no fuel came out. Fuel should be shooting across the street if the pump were working.

I suppose you could also disconnect the return line and have the same result, but the pressure is slightly higher on the high side and it's more accessible.

I checked the fuel pump fuse and it wasn't blown. I also checked the fuel pump relay and it was clicking with the key on. Reference 7:15 on the first video I posted.


Viktor G again at 6:20 on the vid. I pulled the fuel pump connector, and hooked up my multimeter to the 2 big wires that power the fuel pump.

Fair warning. I did this WITHOUT disconnecting the tank straps because I'm used to working in tight spaces, and I didn't want to lower the tank with this harness still connected (because I had a full tank and it could tip off the transmission jack). If you have big hands you may not be able to do this.

I don't have picture of this step, but I went back with the tank out and hooked the multimeter straight to the fuel pump clip in the tank. Same results.


It was showing 9.57 volts with the key ON. I thought it was a little low at first, but I found numerous threads that stated this was normal, and the fuel pump control module could module voltage.

I also connected the fuel pump in the fuel basket without the tank (NEVER do this unless you're sure the pump is dead, because running a dry pump will kill it). As suspected, the pump didn't run.

Interestingly though, when I hooked the pump straight to battery voltage (be careful of fumes), it did buzz faintly.

I am now 100% sure the stock Denso pump is dead.

I followed Viktor G's video mostly, and supplemented with the last video to confirm the charcoal canister removal.

I was able to unplug all the connectors and unclip all the harnesses before lowering the tank. I had to do this because I had just filled up. A full tank weighs about 200 pounds. If you do this by choice, I highly recommend you run the tank as dry as possible.

My only other problem was the tank strap bolt. They were quite rusty. They wouldn't come off with hand tools so I soaked them overnight with PB Blaster (and tapped them lightly with a hammer to vibrate the rust loose). You don't want to use heat near the fuel tank (esp. with fumes everywhere).


The rear strap bolt was quite problematic. You can see from Viktor G's screencap, the bolt is angled very close to the strap. It is impossible to fit an impact socket. That's why you see him with a thin-walled socket (not quite kosher, but necessary).

The other thing was I had to put the transmission jack on the tank to take weight off the strap. Otherwise, as the weight of the tank pulls the strap down, it wants to push the socket off the bolt and strip as you try to impact.


Otherwise, I followed the instructions on both videos and the tank came out just fine.

I had to siphon out the extra 26 gallons with a hand pump from Home Depot. I filled up 2 cars and several fuel containers. If I were home I'd use my external fuel pump to siphon the fuel pump, but I was on the side of the road.

The only hard part was I had to get the tank off the transmission jack to access the fuel lid. It would be much easier if the tank were dry.

I used this tool to remove the lid. I think it works much better than the Toyota SST: 1044 - Toyota/Lexus Fuel Tank Lid Wrench (ctatools.com)

I made sure to blow out all the dirt before removing the lid.

I followed Viktor G's instructions to remove the pump. At this point I could do what he did and just replaced the Denso pump with an Aeromotive plug-n-play pump; however, member Sumo91 strongly recommended that I bypass the donut filter: URD fuel pump kit install w/pics | Toyota Tundra Forum (tundras.com)

I think it's a good idea because you can't buy the filter separately, and the entire fuel pump basket assembly is $500 and on backorder from Toyota.

I can see dirt in the original filter, and it could clog and kill the new pump.

I guess I could go with an aftermarket unit, but I don't want to do this job again for a very long time (and the least of which is getting stuck on the side of the road late at night).

On April 26, 2022, after numerous recommendations from this forum, I ordered the Underdog Racing fuel pump kit with the Aeromotive 340. You can see my review here: Why is the Underdog Racing fuel pump kit so good? | Toyota Tundra Forum (tundras.com)

The kit came next day, and I admit it was packaged well.


The problems I've found so far is that the instructions are no good (they're for Tacomas), and the in-tank hose is too short, at 7-1/8" it wouldn't even go into the basket.

I looked at a lot of threads on the Tacoma forums, and they all recommended a 10" corrugated line to replace the rubber line.

As of today, May 5, 2022, I'm waiting for delivery of the corrugated fuel hose with crimp on clamps: QFS 8mm x 8mm Clear/Black Corrugated Flex Hose Fuel Line & Clamps (Clear or Black) (highflowfuel.com)

I also ordered a new fuel pump lid gasket from Toyota, which is also on the way.
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The fuel hose arrived. I followed Underdog's instructions, and encountered a few problems.



They provided the Aeromotive 11542, with the inlet inline with the outlet. If I did it again, I would order 11541 with the inlets and outlets opposite each other. That would put the outlet closer to the outside of the basket and more in line with the hole in the lid for the basket = less strain on the high pressure fuel line. Like this thread on the Tacoma forum:
Improving the URD Fuel Pump Kit

The other issue was that the heat shrink butt connectors provided by Aeromotive are too big. They won't shrink down to make a tight fit over the wires = live current touching fuel.

I emailed Aeromotive but they have not responded. Meanwhile, I sourced nylon coated heat shrink butt connectors from Home Depot. I really hope I don't die from doing this.