2019 Bullitt Fuel Pump Driver Module failure

[NGOT8R]

Some of you may know that I recently finished running all new fuel line after encountering a rupture in the factory fuel line. I took the car out this afternoon to wash it and fill it up with E85 I. Preparation for going to the drag strip tomorrow and ran into another fueling issue at the car wash, right after ai paid and the attendant raised the mechanical arm to let me through. The car started stumbling violently and then died and wouldn’t restart. I checked for DTCs on my nGauge and found the following codes:

P0103 - Mass or Volume Air Flow “A” Circuit High
P025A - Fuel Pump Module Control Circuit/Open

The only warning I received was about a mile away from the car wash. I smelled the distinct odor of something electrical burning. Further investigation revealed the source of the odor to be the Fuel Pump Driver Module. Long story short, I got hold of my wife, gave her a list of tools and supplies to bring to my location and I was able to bypass the FPDM with two 12 gauge jumper wires that I made on the spot. In addition, the fuel pump fuse (#49 in the engine bay fuse holder) had also blown, so I swapped it out with the driver’s side power window fuse of the same amperage (30A). The car started up instantly without missing a beat and I was able to drive home without having to call for a tow truck. Here are a couple of pics that I took to show how to bypass the FPDM should anyone else encounter this problem on the road.

For a minute there, I was about ready to put a bullet in my Bullitt. At least I’m locating all of the weak links one at a time. I’ll research this more to see if this is common or a fluke for a car running E85 with only 8600 miles on it.

Let‘s recap what’s happened fuel related in the last year.

- Fuel pump failure @ 7K miles
- New DW400 pump (without check valve installed)
- Added inline Deatschwerks check valve
- Factory fuel line rupture
- Fuel pump driver module

Hopefully this is it for fueling issues moving forward.

Sponsored

 

[SheepDog]

Are you using a fuel pump booster?

 

[NGOT8R]

Are you using a fuel pump booster?

Yes, I have the JMS BAP which only comes on at or near 3/4 throttle. I have it set on the lowest voltage setting 18V.

 

[SheepDog]

Yes, I have the JMS BAP which only comes on at or near 3/4 throttle. I have it set on the lowest voltage setting 18V.

Hmm, well something certainly over-loaded the FPDM. Probably time for a big boy fuel system, to go along with your new supercharger

 

[NGOT8R]

Update: Upon investigating the source of the residual burned smell today, I found a few more interesting things. The first thing I noticed was the JMS BAP wiring (red and white wires) that run from the BAP to a weather pack connector and then step down to smaller gauge red and white wires, was burned up, leaving a hole in the side of the weather pack connector’s housing. The heat was so intense in that are, that it fused the connector together, thus preventing me from disconnecting it. In addition, the 40A fuse in the BAP’s fuse holder also got hot, melting the body of the fuse. When I went to pull the fuse from the holder, only the body came off, leaving the fuse blade itself (which was intact and not blown), still in the holder.

Upon making these discoveries, I decided to plug up the FPDM to see if the car would start, which it did. However, the wiring for the connector that plugs onto the FPDM and the FPDM started to feel very warm (this may be normal, but I don’t know). I decided to see just how warm the connector and FPDM were, via my infrared temperature gun (see pics below). Is it possible that a couple of people can check the FPDM and wiring connector on their cars once their engine reaches normal operating temperature and report back here to let me know if theirs also get hot?

Now begs the question of, does anyone know what could have caused this meltdown of the JMS BAP after 3 1/2 years of use? Thanks

 

[SheepDog]

Potentially high resistance at the pump (meaning a loose connection, or wire that is too small). Either the connector on top of the hat, the wiring to the pump itself, or internal resistance. BAP's are really just a bandaid solution to delivering more fuel. The pumps were never designed to run at 18-22v.

 

[NGOT8R]

Potentially high resistance at the pump. Either the connector on top of the hat, the wiring to the pump itself, or internal resistance. BAP's are really just a bandaid solution to delivering more fuel. The pumps were never designed to run at 18-22v.

Even though the DW400 is a plug and play setup? I’m thinking of leaving the BAP out of the fuel system. The only reason I I stalled it to begin with was to make sure I didn’t have fueling issues when using nitrous with the factory pump. Hopefully the DW400 will support the 150 shot on E85. FYI, the car dyno’d at 639rwhp and 602rwtq.

 

[SheepDog]

@NGOT8R another thing to note- You want the wires to be as short as possible. The longer they are, the more resistance there is

 

[SheepDog]

Even though the DW400 is a plug and play setup? I’m thinking of leaving the BAP out of the fuel system. The only reason I I stalled it to begin with was to make sure I didn’t have fueling issues when using nitrous with the factory pump. Hopefully the DW400 will support the 150 shot on E85. FYI, the car dyno’d at 639rwhp and 434 rwtq.

I think a lot of people run a DW400 and BAP, and it works but overdriving anything is always going to shorten its lifespan. However as mentioned, the issue may be a poor connection instead, or improperly sized wires

 

[ice445]

BAP = trash imo. Perfect excuse to delete that.

 

[Cobra Jet]

If the wiring and connector has been in there for 3 years with no issues, then you have another issue that is causing a short somewhere. Have you checked under the car for any harnesses that may be chafed or chewed through by rodents?

I’d be checking wiring harnesses and resistances before you’re a rolling Hindenburg….

 

[NGOT8R]

If the wiring and connector has been in there for 3 years with no issues, then you have another issue that is causing a short somewhere. Have you checked under the car for any harnesses that may be chafed or chewed through by rodents?

I’d be checking wiring harnesses and resistances before you’re a rolling Hindenburg….

My bad, I should have updated this thread. The BAP is back up and running flawlessly. You hit the nail right on the head. It was in fact a short. The were two wires in the throttle control harness (black and gray with ring terminals underneath the dash) that were touching and shorting out. I put a piece of heat shrink over each ring terminal to correct that problem, and then cut out the burned weatherpack connector and soldered the wires together and double heat shrined each wire as well. Lastly, I checked the activation threshold via the TPS reading on my nitrous controller’s touch screen and confirmed that the BAP doesn’t activate until I reach 40% throttle.

 

[NGOT8R]

The new FPDM is here, should I ever need it, but I probably won’t, now that I bought it, lol.

 

[Cobra Jet]

My bad, I should have updated this thread. The BAP is back up and running flawlessly. You hit the nail right on the head. It was in fact a short. The were two wires in the throttle control harness (black and gray with ring terminals underneath the dash) that were touching and shorting out. I put a piece of heat shrink over each ring terminal to correct that problem, and then cut out the burned weatherpack connector and soldered the wires together and double heat shrined each wire as well. Lastly, I checked the activation threshold via the TPS reading on my nitrous controller’s touch screen and confirmed that the BAP doesn’t activate until I reach 40% throttle.

Good to hear you were able to find the source of the issue! Yea, that could have been a disastrous result if you didn’t experience that stall issue at the car wash that day.

I kind of figured it had to be a shirt somewhere in the wiring after you said it was set up as such for 3 years now and not just a recent modification.

Glad to see it all worked out and you’re back to being on the road again.

 

[Leosegura155]

So I have a similar issue happening but I’m not a running a BAP.

2019 Mustang GT edelbrock supercharger 2650 stage 1.
Sai Li dual pump return style fuel system.

I am running 2 DW400 fuel pumps with my setup. I went in to work like any other day and the car was running fine. After my 12 hour shift my car did not want to start anymore. My fuel Pressure regulator was at 0 and pumps were not priming or starting at all. After days of research and checking all the wires I found the following.
1. Blown 20Amfuse in the fuel system harness
2. The connector on the fuel pump top hat was stuck and fused with the fuel pump hat.
3. My fuel pump driver module was not functioning even after buying a used one to test out.

I was able to remove the connector from the top hat and saw that it had gotten too hot and fused itself. Cleaned it up and was ready to be used again.

buddy of mine came to this forum and found the bypass for the FPDM and just like that the pumps kicked on and I had fuel pressure back in the car. One thing we noticed was that as the car was running the connection wires on top of the fuel pump hat were starting to get warmer And the relays on the same fuel system harness were getting warm too but not as much as the one on top of the fuel pump hat.

what could be causing the wires to the connector to heat up? Faulty harness? My only option at this point is to buy another harness from lethal performance if it means it will fix the issue. What do you guys think?

Sponsored