Mechanic replaced the fuel pump first, then said the fuel pump control module was also bad, is this a normal diagnostic process?

KRISTOFOR RAHMAS

MEMBER
2016 TOYOTA TUNDRA
84,000 MILES

My truck listed above stalled while driving and eventually wouldn’t start. I had it towed to a shop. They said the fuel pump failed and replaced it, but the truck still didn’t start. They then said the fuel pump control module (FPCM) was also bad, and both had to be replaced. I was charged for both.

They discarded the old pump, so I couldn’t test it, and no diagnostics were shared before replacement. They also said the battery was dead and recharged it, but I later found out it was bad.

I’m asking mechanics:

Is it standard to replace the fuel pump before confirming the FPCM?

Could both fail at the same time?

What would proper diagnostics look like in this case?

Just want honest input to understand what’s typical. Thanks.

Thursday, April 3rd, 2025 AT 3:46 AM

1 Reply

AL514

MECHANIC
5,499 POSTS

Hello, this is not a typical way to diagnose a low/no fuel pressure issue. It sounds like they checked for fuel pressure, saw none, and may have just tried to repair the vehicle by replacing the pump. These newer systems can work on communications to the control module, and it controls the pump. Service information provides steps to diagnose a no pressure situation, but some shops just throw parts at a vehicle until they get it started, but obviously this is incorrect, and ends up costing the customer more than it should.
For example, what if the real issue is just a bad wire to the fuel pump control module? You should not be charged for a new pump and control module, which I can imagine are very expensive. They misdiagnosed this issue; you should not pay for that.

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Thursday, April 3rd, 2025 AT 6:15 PM