Need peoples thoughts.

[Halefury]

2005 Ford Sport Trac 4.0L V6. The Truck started stalling after a few blocks of driving. Read codes got P1237 so I replaced the Fuel Pump Driver Module and Fuel Pump Inertia Switch . Stalling went away and code reset it self after a few cycles. Code came back so I changed the Fuel Pump with a new Delphi pump. Reset the Codes with ODB2 scanner. After driving it for a few times Code came back. Still showing P1237 and all three main components are New... Checks connections at FPDM no corrosion, Pins look fine and no frays anywhere. Checked grounding wires , they seem to be tight and secure.

 

[Todd Z]

Check the relay under the hood, swap it with another, it can cause that code too.

 

[Halefury]

Check the relay under the hood, swap it with another, it can cause that code too.

Went to the Autostore and grabbed a new Fuel Pump Relay and installed still same issue. I tried Resetting the code with my ODB2 scanner but code just pops right back up. All parts are brand new now.

 

[Dmiranda1269]

Went to the Autostore and grabbed a new Fuel Pump Relay and installed still same issue. I tried Resetting the code with my ODB2 scanner but code just pops right back up. All parts are brand new now.

Just because there's a new part doesn't mean it's a working new part, my Dad tells me in his shop everyday he sees people replacing good parts with cheap Chinese parts because they are guessing.


Have you done any tests?

 

[Halefury]

Didn't use cheap Chinese parts. I ordered OEM parts. Did use Delphi pump because Motorcrafts was out of stock and dealership here was having issue locating that pump in stock anywhere. Thinking it may be a ground issue that hasn't been found yet. So far no problems with ground on connections and everything is secure and no frays unless it's behind the firing wall going back to the PCM. Delphi was $350 but came with lifetime warranty which wasn't a bad thing.

 

[Dmiranda1269]

Didn't use cheap Chinese parts. I ordered OEM parts. Did use Delphi pump because Motorcrafts was out of stock and dealership here was having issue locating that pump in stock anywhere. Thinking it may be a ground issue that hasn't been found yet. So far no problems with ground on connections and everything is secure and no frays unless it's behind the firing wall going back to the PCM. Delphi was $350 but came with lifetime warranty which wasn't a bad thing.

See too many purchase parts on Amazon

 

[gkid]

1237 - Fuel Pump Secondary Circuit Malfunction

Description:	Note: For LS and Thunderbird, the FPDM functions are incorporated in the rear electronics module (REM). Also, the REM does not use an FPM circuit. Diagnostic information is sent on the communication link. This DTC indicates that the fuel pump driver module (FPDM) detected a fuel pump secondary circuit concern. The FPDM sends a message to the powertrain control module (PCM) through the fuel pump monitor (FPM) circuit indicating this concern was detected. The PCM sets the DTC when the message is received.
Possible Causes:	Open or shorted FP PWR circuit Open FP RTN circuit to FPDM Open or shorted circuit in the fuel pump Locked fuel pump rotor Damaged FPDM For LS and Thunderbird, circuits associated with the fuel pump relay
Diagnostic Aids:	The FPDM sends a 75% duty cycle (750 ms on, 250 ms off) through the FPM circuit to the PCM while the concern is being detected by the FPDM. If the concern is no longer detected, the PCM returns to sending an all OK (50% duty cycle) message to the PCM. The FPDM controls pump speed by supplying a variable ground on the FP RTN circuit.
Application		Key On Engine Off	Key On Engine Running	Continuous Memory
All		GO to KB31.

 

[cadman777]

gkid has the same info that I have in my diagnostic manual for 2003 vehicles (it's 10" thick!).

What I would do is check each wire on the relevant circuits for:
1. open continuity (using an ohm meter)
2. short to ground
3. short to power
4. high resistance (using a load test, which you can make for yourself by stringing a few 12 volt parking lights together and putting that into series w/the wires you're testing.
5. check power & grounds
If none of that works, and if all your connectors are clean and making a good connection, and if all your components are in good condition and working as expected, then you may have a control module issue.
This is a PITA to track down, but it's what you have to do.

I just did that on a neighbor's GM Silverado that had no brake lights.
First thing I checked was the fuses, but I MIS-READ the diagram and didn't notice a MISSING FUSE in the underhood fuse box...duh!
After an hour of testing all the wires and circuits and cleaning the grounds, I referred back to the wiring diagram and fuse box layout and discovered that I mis-read the fuse box layout!
So I got a fuse I had lying around and plugged it into the spot and it worked.
Before that, I first changed the brake light switch b/c it was not reading when it should have.
So the only thing I could figure is the brake light switch was stuck ON (a known problem w/this truck).
And in order to save the battery, the previous owner pulled the brake light fuse instead of changing the brake light switch!
Anyway, even if I put a new fuse in it at the beginning, I will would've had to do the diagnostic to test the circuit.
B/c more than likely the brake light would have been stuck ON.
Just goes to show that no matter what you do, you STILL have to go through the process of elimination to narrow down the possibilities.

Next week another neighbor has a VW Jetta that has a right side rear wheel speed sensor not reading that needs fixing.
Turns out that's a common problem w/them.
So I absolutely MUST check the wires to eliminate the possibility of it being the ABS unit.
The ABS units on these are known to go bad.

No matter what, you gotta take the time an aggravation to do the tests on the wires, connectors and circuits if it isn't an 'easy fix'.