This is a 2005 thru 2009 ford f150 fuel pump driver module from Dorman. I know people crap on their stuff but when I cut this open I found it to be pretty well made and designed. They get acceptable reviews too. However after 1 month of use my truck would start dying after 15 or 20 min and could not be restarted. You had to sit 30 minutes or longer to get it to work again. Now that I got my warranty replacement I want to play around with it as I am excellent at hot air rework and soldering. After testing a bunch of items on this board and ruling out any bad solder joints I was wondering what component to look at first that would fail after some runtime.
What surface mount component would fail after 15 min of use?
- Thread starter Fordiesel69
- Start date
Usually those fail from corrosion from where they mount on the frame.
Voltage regulator heats up and fails.
I would be more worried about them sourcing bad parts (Chinese knock off caps).
1. It is a name brand nichicon cap. Under that sticker there is no sign of electrolyte leakage.
2. This is a new part (May 2024) it is not corroded.
3. Board and parts may very well be from china, but this one is a dud.
So the VR is at U3 and the control IC is at U1.
2. This is a new part (May 2024) it is not corroded.
3. Board and parts may very well be from china, but this one is a dud.
So the VR is at U3 and the control IC is at U1.
Intermittent faults are the worst, but at least you have an idea--it's likely heat related. Visual inspection should rule out cracked solder joint; however, a cracked copper trace, particularly at a plated thro-hole can occur. As can barrel cracking. But you'd hope that an automotive rated PCB would be unlikely to have that...
With that big inductor and capacitor I'm thinking it's bucking the 12V to run the pump--perhaps it's variable pressure? I'm wondering if as it gets hot that the capacitor ESR is going up and causing excessive ripple. I'd think it'd still work though, unless if the regulator senses a fault and faults out.
This comes up as an 8 bit MCU with CAN bus support. Link.
This is the switch mode supply--and of course, it's not marked. Traces on D5 look too small to be part of the main current loop; not sure what it's for. D1 is the diode I bet. Not sure what Q2 is for; that can be the transistor for this, or perhaps it's just a pass transistor for something else (maybe passes power to something else). Its too far from the inductor in my opinion to be part of this circuit (but could be part of the fault all the same).
I'm guessing the upper damage here is from you opening it. But the lower damage around the mouse bites is concerning--it's how I'd break apart boards, but I'm not paid to properly depanelize.
Everyone does it, probably fine, but eh.
Lots of possible failure modes, and without knowing the devices, to find fault flags or what to look for on an oscilloscope, it's just guessing in the dark.
Whoever did this layout had zero cares about silkscreen clipping...
With that big inductor and capacitor I'm thinking it's bucking the 12V to run the pump--perhaps it's variable pressure? I'm wondering if as it gets hot that the capacitor ESR is going up and causing excessive ripple. I'd think it'd still work though, unless if the regulator senses a fault and faults out.
This comes up as an 8 bit MCU with CAN bus support. Link.
This is the switch mode supply--and of course, it's not marked. Traces on D5 look too small to be part of the main current loop; not sure what it's for. D1 is the diode I bet. Not sure what Q2 is for; that can be the transistor for this, or perhaps it's just a pass transistor for something else (maybe passes power to something else). Its too far from the inductor in my opinion to be part of this circuit (but could be part of the fault all the same).
I'm guessing the upper damage here is from you opening it. But the lower damage around the mouse bites is concerning--it's how I'd break apart boards, but I'm not paid to properly depanelize.
Everyone does it, probably fine, but eh.Lots of possible failure modes, and without knowing the devices, to find fault flags or what to look for on an oscilloscope, it's just guessing in the dark.
Whoever did this layout had zero cares about silkscreen clipping...
If you're handy you can get replacement parts from www.mouser.com. Otherwise demand a replacement.
Did the Dorman kit come with posts to shim the FPDM off the frame to prevent corrosion on the interface with the frame? Crown Victorias from the same era have the the same FPDM and it’s inside the trunk where it never corrodes through the case which is the main failure mode of these. It’s probably a $10-$15 part at a Pick-N-Pull and I’d bet more reliable than Dorman version.
The pump should be constant pressure, but it is pulse width modulated. Not sure if that changes any thoughts that you have?
The ECM reads the fuel pressure from a sensor on the rail and keeps it constant by sending feedback to this driver module to vary the voltage applied to the pump.
The unmarked switching regulator chip is suspect. There are cheap boards you can buy based on these chips which simply reduce or increase voltage to a constant. A lot of people noted that the chips are counterfeit / knockoffs of the real National Semiconductor part and they don't last.
The unmarked switching regulator chip is suspect. There are cheap boards you can buy based on these chips which simply reduce or increase voltage to a constant. A lot of people noted that the chips are counterfeit / knockoffs of the real National Semiconductor part and they don't last.
No, should still be the same.
Their replacement module seems to be fine. But time will tell.
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