2016 Low Press. Fuel Pump

I have a very odd situation with my 2016 Tacoma. I would like some opinions…..

I had a problem with a parasitic drain on the battery. It was about 250 to 300mA. Battery would die sitting in the driveway for few days. I charged the battery and made an appointment with the dealer to investigate. I left the battery disconnected before the appointment and on the morning of the appointment, I connected the battery and started the truck. It cranked longer than normal, but started and I thought it was fine until I tried to move the truck. Even slight pressure on the accelerator caused the engine to stumble and die. I ended up getting a tow to the dealer

After it arrived, I watched them start the truck and move it into the service bay. I eventually got a call from them saying the pump was dead and I needed a new pump to the tune of $1200. No, there is no recall on that pump. So, I had them install it.

I got a call from them when the job was done. They told me that the truck still idled poorly with the new pump. Then, they told me they discovered a blown 10 A ECM fuse. Replacing the fuse caused the truck to now run normally.

My conclusion from all of this is that the problem all along was that blown fuse. They claim there was a bad pump error code before they replaced the pump. They claimed the pump was dead. So my question is, how could the truck run if the low pressure pump was not pumping to the engine? Why did the new pump behave like the old pump until they replaced the fuse? My conclusion is that I just paid $1200 for a blown fuse. What do you all think?

Oh, and the parasitic drain disappeared when they replaced that fuse. I maintain that Ohm’s Law caused the fuse to blow. Low battery voltage would cause higher current, hence blowing the fuse

Also, what you do you all think I should do? I am inclined to open a case with American Toyota and get them to investigate. So far I have not found out any method of testing the pump. And, yes, I demanded my old pump back, so I have it.

 

It's gonna be very hard, to impossible to prove. I'm guessing you don't have print out of code thrown. Plus hard to believe a blown fuse cause parasitic draw. Your run rough yes, draw no. Bad pump yes, could cause. You can sit down with shop/general management and see if you can come to some discount service. Do that first, be NICE. Going over their head isn't a good first move.
Goodluck your going to need it.

 

Quite the pickle...
By the same token, how's the low pressure fuel pump work(even poorly) with a blown fuse? I suspect they are alluding to EFI NO. 2?

 

Well I am betting that it’s the ECM fuse. According to the info you provided (thanks) the ECM fuse controls the speed of the pump. If that fuse is blown, it appears that the pump will run, but at the wrong speed. It likely wouldn’t speed up when you place extra fuel demand on it. That’s why it would idle, but when pushing the gas pedal would cause the engine to die as the ECM could not tell the pump how much fuel to deliver. I think this supports my case.