Fuel Pump Control and Trailer Brake control module combo WTF?

[txbandit44]

Im sure no one here came up with this but why would the FPCM and the TBCM be combined. What does stopping a trailer have to do with pumping fuel?

 

[Bill 1960]

Who says it is?

I replaced the FPCM on mine, had nothing to do with trailer functionality.

I’ll be interested to see if this is actually true in some vehicles or just a misunderstanding.

 

[txbandit44]

Looking at the wiring diagram it is on series 10 1/2ton 2012 Yukons

 

[Bill 1960]

I don’t see any connection to the fuel pump in that schematic. Perhaps there’s a typo in the document?

Edit: figured out later it’s likely a multi-purpose module that can be used in more than one function. Just like a relay, only more complex. What do trailer brakes and fuel pumps have in common? PWM.

So it’s not doing both things in combination. It’s programmable at the dealer or shop to be either a brake control driver or a fuel pump driver. Not both at once. That explains why FPCM replacements need a tech 2 or something to set them up.

From that perspective it makes sense to build only one PWM module and use it in two places.