Bypass Fuel Pump Module

[Stoggy]

Lots of you folks have had the pleasure of paying multiple tow bills to the dealer to get the dreaded fuel pump module repaired—if not for a little while. Well, fool me twice. I figured out how to bypass it temporarily while I order a new module and install it myself.

With just a little electrical knowledge and some patience you can do this. Took me about 45 minutes taking my time.

Back story: car broke down, duh, luckily had my electrical kit with me so I began digging into connector at module and figured out what is power and ground supply to and from the module and fuel pump. Fashioned some temp jumpers out of 12awg wire and jammed them in the cavities as seen below:

jumper-wires.jpg (22.94 KiB) Viewed 50225 times

Doing it this way forced me to leave the connector unplugged which, no big deal, engine ran fine for several hundred km on the way home. The wrench icon did come on and stay on but no codes thrown.

Get back to my shop and I permanently installed a set of jumpers. Pics attached. Basically I just made a removeable power and ground loop which I can simply plugin and boom, bypass the fuel pump module altogether. It also allows me to leave it plugged in and thus the wrench light stays off.

Two wires spliced together:

splice1.jpg (18.89 KiB) Viewed 50197 times

splice2.jpg (13.58 KiB) Viewed 50197 times

Permanent jumpers installed:

jumper1.jpg (29.13 KiB) Viewed 50192 times

jumper2.jpg (24.59 KiB) Viewed 50192 times

jumper3.jpg (34.52 KiB) Viewed 50192 times

jumper4.jpg (24.75 KiB) Viewed 50192 times

I do not recommend keeping it permanently bypassed as in a collision the restraints module can actually turn off the fuel pump. Also I’m not entirely sure what relation the pcm has to this module but they are connected. Perhaps it is just an on/off switch as the module is powered at all times when key on.

The wires you want to connect together are:

WHT/TAN and BLK/GRN - this is the ground circuit
YEL/GRY and VIO/GRN - this is the power circuit

If your colours vary, it is the 4 large wire gauge pins numbers 1,4,5,8. 1 and 5 get jumped together and 4 and 8 get jumped together.

Jumping those connections will turn on the fuel pump allowing you to start the engine. The fuel pump will be ‘on’ any time the key is on.

Anyways, I plan on keeping my jumpers in the glove box. I always a small tool kit anyways which has the 7mm socket needed to remove that C pillar panel so I shouldn’t have to pay for a tow again.

Hope this helps you guys. I know a lot of you are handy and can do this mod yourselves.

Obviously if you’re under warranty I would not suggest this. My car is out of warranty. Of course common sense prevails, do not do this if you don’t know what you’re doing with electrical and always make sure the key is off.

[Stoggy]

Wanted to add some more info to this post but can't edit. In the pursuit of trying to sort out why these modules constantly fail I will continue to update this thread with any and all information I come across. Even if this information just helps someone sort out how it works then I've accomplished something here.

Theory of operation:

Fuel Pump Control Module (FPCM) regulates fuel pressure by controlling fuel pump speed and current flow. Fuel Pump (FP) receives a Duty Cycle (DC) signal from the FPCM to control FP operation. Then sends a DC signal to the ground side of the FP to control speed and current flow. The FPCM also sends a feedback signal to the PCM for diagnostic information. A 60% DC indicated all circuits are ok. Ann 80% DC indicates the FPCM has detected a fault in circuits between FPCM and the FP. A 20% DC indicates FPCM did not receive a FP Duty command from the PCM or the Duty was invalid.

Here is the schematics for the fuel circuit:

Fuel Pump Module 1.jpg (95.14 KiB) Viewed 50190 times

Fuel Pump Module 2.jpg (76.06 KiB) Viewed 50190 times

Here is the FPCM connector:

Fuel Pump Module Connector.jpg (10.92 KiB) Viewed 50190 times

The wire colours may vary from what you have but the pinout is the same. I've only listed the pins that pertain to the FPCM:

PCM Pinouts:

27 - FPM - BROWN/WHITE - Fuel Pump Monitor
39 - FPC - YELLOW/ORANGE - Fuel Pump Command

FPCM Pinouts:

1 - VPWR FUEL - VIOLET/GREEN -
3 - FPC - YELLOW/ORANGE - Fuel Pump Command
4 - GND - BLACK/YELLOW - Ground
5 - FPPWR - YELLOW/GREY - Fuel Pump Power
6 - ENS - YELLOW/VIOLET - Event Notification Signal
7 - FPM - BROWN/WHITE - Fuel Pump Monitor
8 - FPR - WHITE/BROWN - Fuel Pump Return

[Flexmood]

Hi... I've studied your post quite a while, to see if could help in solving a NO START, error P025A

The anomaly I found is with pin 1 that shows no voltage... pin 7 does show 11.7V
Any guess???
thanks

[Stoggy]

Hey Flexmood! Sorry to hear you’re having troubles with your Flex. Based on no voltage on pin 1 of the FPCM, I would start by checking to make sure fuse F56 (30A) is in working order, as the power supply begins here.

If you have voltage across the fuse then the next place to look is the fuel pump relay. With the key off, pull that relay and put your voltmeter on pin sockets 1 and 3 of the fuse block you should have 12 volts on both sockets.

If so then check for ground on pin socket 2 with the key on. A helper may be good here as the BCM will only provide ground on that wire for a few seconds, enough to prime the fuel system. If the engine isn’t started after that time then the BCM will drop the ground and look for a signal from the crank position sensor.

If you get a ground there, put a jumper wire between pin sockets 3 and 5 and try to start the vehicle. What this does is bypass the fuel pump relay and BCM ground altogether and puts power directly to pin 1 of the FPCM. To be sure, measure voltage at pin 1.

If you get voltage at pin 1 of the FPCM, then check for voltage on pin 5 of the FPCM. This pin is what supplies voltage to the fuel pump. No voltage here likely means a defective fuel pump control module.

It’s worth noting that when my FPCM failed the engine would still turn over, I’m assuming yours does too, and it sounds to me like a bad fuse or faulty relay. Let me know how you make out.

[Flexmood]

Hi Stoggy... thanks for your reply
According to the Fuse Block scheme, FP fuse is n.27 (mini 15A FP Driver Mod & FP)
Relay has 12V on both sockets. Checked 'em and have Voltage
! A difference I found on the other 2 pins are normally grounded (even without turning key ON)!
On the connector side: Pin 1 has no voltage, Pin 7 has 12V

I was tempted to jump 7 (instead of 3 ) to 5, but didn't.
Pin 3 & 7, from your scheme, both come from PCM... only 7 has Voltage

[Stoggy]

You definitley don’t want to jump pin 7 to pin 5 on the FPCM connector.

While your fuse block may be slightly different than the diagram above, pins 3 and 5 of that fuel pump relay are what allow voltage to flow through to the FPCM, and ultimately the FP. If you jump those at the fuse block (using a small piece of wire) you should be able to start the car. Make sure the FPCM connector is plugged in.

Again, you are bypassing the fuel pump relay in the fuse block (as your symptom was described as no voltage on pin 1 of FPCM) NOT at the FPCM connector. This relay supplies power to the FPCM and in bypassing it completely disregards the ground normally supplied by the BCM.

I hope this helps.

[Rtg2010]

Lots of you folks have had the pleasure of paying multiple tow bills to the dealer to get the dreaded fuel pump module repaired—if not for a little while. Well, fool me twice. I figured out how to bypass it temporarily while I order a new module and install it myself.

With just a little electrical knowledge and some patience you can do this. Took me about 45 minutes taking my time.

Back story: car broke down, duh, luckily had my electrical kit with me so I began digging into connector at module and figured out what is power and ground supply to and from the module and fuel pump. Fashioned some temp jumpers out of 12awg wire and jammed them in the cavities as seen below:

645064D4-FBF6-409B-964C-9B4DE405D694.jpeg

Doing it this way forced me to leave the connector unplugged which, no big deal, engine ran fine for several hundred km on the way home. The wrench icon did come on and stay on but no codes thrown.

Get back to my shop and I permanently installed a set of jumpers. Pics attached. Basically I just made a removeable power and ground loop which I can simply plugin and boom, bypass the fuel pump module altogether. It also allows me to leave it plugged in and thus the wrench light stays off.

Two wires spliced together:
04F2A559-FA7D-42DF-ADDE-7C1DE60EFB20.jpeg
0D1738AA-CBCA-4A9B-B2AD-A3DC8ACA7290.jpeg

Permanent jumpers installed:
5231764C-EACE-4259-969D-AEC37C162EE8.jpeg
46180193-D867-424F-A417-3761C6467889.jpeg
0FA2C684-6CE7-47EC-8495-8F18AC5C1B86.jpeg
FC868649-D2DD-4F8A-B0D5-500DDB6B8A0F.jpeg

I do not recommend keeping it permanently bypassed as in a collision the restraints module can actually turn off the fuel pump. Also I’m not entirely sure what relation the pcm has to this module but they are connected. Perhaps it is just an on/off switch as the module is powered at all times when key on.

The wires you want to connect together are:

WHT/TAN and BLK/GRN - this is the ground circuit
YEL/GRY and VIO/GRN - this is the power circuit

If your colours vary, it is the 4 large wire gauge pins numbers 1,4,5,8. 1 and 5 get jumped together and 4 and 8 get jumped together.

Jumping those connections will turn on the fuel pump allowing you to start the engine. The fuel pump will be ‘on’ any time the key is on.

Anyways, I plan on keeping my jumpers in the glove box. I always a small tool kit anyways which has the 7mm socket needed to remove that C pillar panel so I shouldn’t have to pay for a tow again.

Hope this helps you guys. I know a lot of you are handy and can do this mod yourselves.

Obviously if you’re under warranty I would not suggest this. My car is out of warranty. Of course common sense prevails, do not do this if you don’t know what you’re doing with electrical and always make sure the key is off.

I have a 2010 f150 lariat. I have spent countless hours trying to figure out my problem this thread has been most helpful so i was hoping i could pick your brain.
I have a crank no start issue. Everything pointed to the fdpm so i bought one and changed it. Boom truck fires up. Shut it off fire it up again and again. Nice! Problem solved off to the lake i go. Stopped at a friend's cabin after about 30 min back to no start. Started the next morning but died twice going back to town (20km) second time i got a tow. This is when i found your magic trick to bypass. I did this and she runs like a champ again. Bad (new) module that sounds like my luck. I get one right from Ford install still won't run. Bypass it fires right up. I've checked the fuse, and relay. Even bypassed if i pull either while running truck stalls. I'm pulling my hair out. I really don't want to buy another module because you can't return them. Why would it run perfectly bypassed but not at all plugged in? If you can provide a direction it would be greatly appreciated!

[Stoggy]

RTG, glad this post was able to help out! I don’t have the schematics for your truck, but I will guess that it is largely the same. If so, the FPCM sends and receives signals from the PCM to maintain correct operation. If you’re plugging in a new module and the engine is cranking, but not firing, then I’d suggest there’s an intermittent issue on that circuit. This could be as simple as a wire moving around or wiggling around when it shouldn’t be and causing an intermittent short. This is only a guess.

I was never fully able to solve the same issue on my Flex even with all the schematics and tools, etc. and so I resorted to installing this bypass. For what it’s worth, I have a faulty FPCM currently installed in the car—the same one from when I wrote this tutorial—with the bypass connected and I haven’t had any issues whatsoever.

The only ‘real’ concern that arises from bypassing is that your fuel pump is now running at full capacity rather than the modulated capacity which is based on engine needs, i.e.: throttle position.

My suggestion is to install the removable bypass as I’ve done and then call it a day! Hope this helps.

[Stoggy]

RTG, to answer your other question:

It will work perfectly when completely bypassed because the PCM is no longer included in the fuel pump power supply circuit. You are literally ‘hot wiring’ power from the fuel pump fuse, through the fuel pump relay, right to the fuel pump in the tank. This is why if you remove the fuse or the relay the engine will die.

There is no harm in this new circuit as the fuel pump is still protected by the fuse before the relay.

[Myst170]

Would this work on a 2015 fiesta st since I think they are fuel on demand

[Stoggy]

Not sure if the electrical systems are the same. You’d have to look up the FPCM for the Fiesta and Ford and see if they’re the same part number.

[Myst170]

I have a 2015 fiesta with a fpcm fault saying low power to ground wondering if you could help

P025C-11 and P053F-21 codes

[Stoggy]

Sorry to hear about your troubles mate. Control Circuit Low indicates some type of issue with the driver signal from the PCM to the FPCM. I don’t have Fiesta specific schematics but, if it’s like other Ford’s, and it probably is very similar, the PCM (Powertrain Control Module) is what dictates the operation of the FPCM.

If you look at my diagrams above you’ll see power to the FPCM comes from the Fuel Pump Relay, and then the controls from the PCM come in on FPM and FPC. Likely your issue is on one of these two wires (again, if it’s similar to the Flex).

I’d read through my post again and digest the diagrams carefully. See if you can ‘jump’ your FPCM the way I did. If the car runs, then you likely have a faulty FPCM. If it doesn’t, then you have some issue with the PCM.

[Myst170]

Is there a way to test if they are good using a multimeter?

[Myst170]

And am I looking for a broken or damaged wire

[Stoggy]

To test with a multimeter you’ll first have to know what voltages you’re testing for, which I can’t give you as I don’t have the factory service manual for your vehicle.

Second, these wires may be a PWM signal which can be difficult to measure with a multimeter.

Third, yes one of these wires may be damaged, or broken.

[Myst170]

Hi I have found where the problem lies it's in the relay for some reason the really is not being switched to allow the pump to run, I've tried a new relay to the same issue so I think there must a problem with the wiring or even perhaps the powertrain control module

[Stoggy]

That helps narrow it down for sure. The relay is likely similar to the diagram above. I’d check for 12v on pin 2 of the relay socket (this should come from the fuel pump fuse and will be hot at all times).

If you have power, then ground will come from the Body Control Module (BCM) and go into pin 1 relay socket. If there’s no ground when key on, then there’s an issue with the BCM or the wire from the BCM to the relay.

[RoadRage]

I've got a 2018. I have two questions, 1 where is the module located?
2 what gauge wire did you use for the jumper?
I'm thinking of keeping a piece of wire and needed tools as a precaution.

[Stoggy]

Passenger side C pillar. You can use 12 or 14 AWG wire.

[chavo18]

That is the cleanest underside i have ever seen!

Thanks for posting this! I have the same problem and suspect the PCM.

Can you please tell me what kind of connectors you used to splice in the bypass?

Thanks!

CP

[Stoggy]

Hey there! This is clean because it’s actually inside the car behind the passenger C pillar. The connectors I used were Deutsch power series connectors and pins.

[Flexsation]

Same issue as everyone else. Cranks but don't start. Replaced fuel pump module at the C pillar and the care turned right over. Next morning, same issue - cranks won't start. Put old module back in and it starts right up. *headscratcher.