Bypassing / Eliminating 2012 5.3 Liter Fuel Pump Control Module E38 Computer

[dave w]

I'm wondering if anyone knows how to bypass or eliminate the fuel pump control module for a 2012 E38 computer. The project is an older Jeep that is getting an engine / trans / t-case from a 2012 GM 4WD pickup 5.3 liter.

Thanks for any information / ideas.

dave w

Fuel Pump Control Module

Fuel Pump Flow Control Module (FPCM) – LMF
The fuel pump flow control module (FPCM) is a serviceable GMLAN module. The FPCM receives the desired fuel pressure message from the engine control module (ECM) and controls the fuel pump located within the fuel tank to achieve the desired fuel pressure. The FPCM sends a 25 KHZ PWM signal to the fuel pump, and pump speed is changed by varying the duty cycle of this signal. Maximum current supplied to the fuel pump is 15 amps. A liquid fuel pressure sensor provides fuel pressure feedback to the FPCM.

Electronic Returnless Fuel System (ERFS) – LMF
The electronic returnless fuel system is a microprocessor controlled fuel delivery system which transports fuel from the tank to the fuel rails. It functions as an electronic replacement for a traditional, mechanical fuel pressure regulator. A pressure vent valve within the fuel tank provides an added measure of fuel pump flow control module (FPCM). Desired fuel pressure is commanded by the engine control module (ECM), and transmitted to the FPCM via a GMLAN serial data message. A liquid fuel pressure sensor provides the feedback the FPCM requires for Closed Loop fuel pressure control.

Liquid Fuel Pressure Sensor – With FPCM
The fuel pressure sensor is a serviceable 5-volt, 3-pin device. It is located on the fuel feed line forward of the fuel tank, and receives power and ground from the fuel pump flow control module (FPCM) through a vehicle wiring harness. The sensor provides a fuel pressure signal to the FPCM, which is used to provide Closed Loop fuel pressure control.

[RobertISaar]

how complex do you want to get? what PCM do you plan on running?

[dave w]

how complex do you want to get? what PCM do you plan on running?

It's the E38 Computer. See attached pic.

I'd like simple, maybe an external fuel pressure regulator and return line instead of the returnless system that was original to the 2012 model year. I don't think that is an option? Maybe the solution is a custom built fuel cell to incorporate all the fuel system features from the 2012 model year donor vehicle.

dave

[dave w]

It seems I'm in the middle of a real challenge. The 2012 is already installed into a 2009 Jeep Wrangler 4 door. I'm thinking I'll need to investigate the option of using the GM 5.3 liter fuel pump control module with the Jeep fuel pump and Jeep fuel tank. The 2009 Jeep Wrangler 4 door uses a returnless fuel system similar to the 2012 GM pickup.

dave w

[lionelhutz]

You should be able to run the Jeep pump (or almost any typical pump) from the module, assuming it will create enough pressure and flow. Can the fuel pressure sensor be mounted on the engine or in the line somehow fairly easily?

It sounds like the tank has another mechanical over pressure valve/regulator. The Jeep might have something similar.

[EagleMark]

Just things to think about... with returnless system it is PWM and somewhere needs a dampener. Does Jeep system have this. Truthfully I don't even know where or how it works on GM but dampener is part of how system stays steady pressure instead of jumpy...