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Discussion Starter #1
Fuel Deliver Problem 97 LSC

I thought my intermittent no start/no fuel was the fuel pump on its way out since when I checked the flow it was minimal. After replacing the pump and the filter it ran a few minutes and died and won’t start. :bawling:

No CE light.





I have verified voltage at “C” which proves the fuel pump relay and the PCM power relay. I have bypassed the inertia switch just in case.

Still no fuel flow.

I have disconnected C401 from the new pump and connected it back up to the original pump assembly with it sitting in a bucket of water.

Still no fuel flow.

I still need to verify G302 to make sure I'm getting a good ground to the module.

To me, the above troubleshooting points to:
1. For some unknown reason, the PCM is not signaling the Fuel Pump Driver Module (FPDM) to run the pump.
2. The FPDM is getting the proper signal, but not providing power to the pump.

How can I determine whether the PCM is or is not sending the signal to the FPDM or if the FPDM is bad? Keeping in mind I’m doing this by myself… (Since it isn’t running, the only time the pump “should” run is for a few seconds when you first turn on the key to prime the system.) So I can’t lay under the car checking signals, while simultaneously turning the key on. :(

I’m thinking of hooking an external power supply directly to the pump to see if the car with run with known good fuel.

Anybody have any other suggestion (besides towing it to a stealership)?

Oh, and in case anyone wants to know the signal from the PCM to the FPDM and it’s resultant reply:

Fuel Pump Driver Module Applications

The Fuel Pump (FP) signal is a duty cycle command sent from the Powertrain Control Module (PCM) to the Fuel Pump Driver Module (FPDM) (Table 5). The FPDM uses the FP command to operate the fuel pump at the speed requested by the PCM or to turn the pump off.

FP Duty Cycle Command: 0 - 5%
FPDM Actions: PCM will not output this duty cycle.
PCM Status: Invalid FP duty cycle. FPDM will command fuel pump full on. FPDM will send 25% duty cycle signal on the Fuel Pump Monitor (FPM) circuit.

FP Duty Cycle Command: 5 - 51%
FPDM Actions: Normal operation
PCM Status: FPDM will operate the fuel pump at the speed requested. ("FP duty cycle" x 2 = pump speed % of full on (for example FP duty cycle = 42%. 42x2=84. Pump is run at 84% of full on.)). FPDM will send 50% duty cycle signal on FPM circuit.

FP Duty Cycle Command: 51 - 67.5%
FPDM Actions: PCM will not output this duty cycle.
PCM Status: Invalid FP duty cycle. FPDM will command fuel pump full on. FPDM will send 25% duty cycle signal on the Fuel Pump Monitor (FPM) circuit.

FP Duty Cycle Command: 67.5 - 82. 5%
FPDM Actions: To request the fuel pump off, the PCM will output a 75% duty cycle.
PCM Status: Valid fuel pump off command from PCM. FPDM will not operate the fuel pump. FPDM will send a 50% duty cycle signal on the FPM circuit.

FP Duty Cycle Command: 82.5 - 100%
FPDM Actions: PCM will not output this duty cycle.
PCM Status: Invalid FP duty cycle. FPDM will command fuel pump full on. FPDM will send 25% duty cycle signal on the FPM circuit.
 

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Discussion Starter #2
Anyone? :2huh:

And for those with the supercharged Gen II's: Did you use the FPDM or did you bypass it and tune out the signals to/from the PCM?
 

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Did you put a stock pump in?

If not..I'll bet you are having the "I didn't switch the power leads" around issue.
 

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Replacement pump assembly was: http://www.rockauto.com/catalog/moreinfo.php?pk=296750

I also took the original pump assembly and plugged it into the car's harness, dropped it into some water and turned on the key. No flow at all.

I swapped the fuel pump relay with one of the duplicates but I didn’t check the PCM relay.

I’m going to build some jumpers today that will let me bypass the FPDM completely (basically pin 9 to pin 10 for 12v to the pump, and pin 2 to pin 3 for the pump to ground). Theoretically it should run but it should also throw a code indicating it isn’t seeing the FPDM. This also proves out most of the harness, including ground.

If that does not work, I’m also building a harness to completely bypass the car’s system and run the pump directly from an external 12v power supply. Just to make sure the new pump is actually good!!

But the first thing I’m going to do is see if there are any codes being stored that aren’t throwing a CE light. Shoot as far as I know the security system is triggered and it is disabling the fuel pump…

Anyway, thanks for the replies/thoughts. When (and if) I get it figured out, I’ll post my results.
 

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Discussion Starter #7
Do you have Voltage at the pumps harness?
That's the 99 cent question.... Since I'm working alone, there's no way I can turn on the key while watching the multimeter connected to the harness under the car. :bawling:

It will only have voltage when you initially turn on the key (to prime the system) and while you are cranking the engine....

And keep in mind it isn't straight 12v, but rather a square wave that varies the speed of the pump. I have yet to find a cross reference of v-dc to pulse width pulse (and I don't have an oscilloscope)... So I don’t even know what the “correct” voltage should be.

I did find out the male pins on the harness that goes to the pump are a perfect fit for a V.35 female pin. If the V.35 male pin will stick (and stay) in the female harness on the car, I can extend my multimeter leads far enough for me to watch it while I crank the car.
 

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Discussion Starter #8
I'm been doing some more research and a "no fuel" might be a correct indication if the PATS is triggered.

And if it is triggered hard (for a plethora of reasons), it locks the system down and it can only be reset by the dealer.... :redmad:

http://www.1-800-pdq-keys.com/news.htm
 

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Sounds to me like a loose connection or a bad or burnt wire harness. When you put the new pump in it could have made it worse. Use long lead wires and alligator clips and see if you have any voltage.
 

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I bypassed the FPDM at the plug for the FPDM (jump pins 9 to 10 and 2 to 3 on C310) and it runs fine. So that proves the new fuel pump, the ground, and the majority of the harness (excluding the harness from the PCM to the FPDM.

With it bypassed it immediately threw a CE light. I haven't scanned it yet, but I suspect it will say no signal from the FPDM.

So anyway, I've found a couple of FPDM's on ebay with the same part number (F7LF-9D370-AA), but they are both from a 97 Continental not a LSC. Any guesses if they are the same, or if the internal code/fuel trim is different? The OEM is discontinued. :(
 

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I bypassed the FPDM at the plug for the FPDM (jump pins 9 to 10 and 2 to 3 on C310) and it runs fine. So that proves the new fuel pump, the ground, and the majority of the harness (excluding the harness from the PCM to the FPDM.

With it bypassed it immediately threw a CE light. I haven't scanned it yet, but I suspect it will say no signal from the FPDM.

So anyway, I've found a couple of FPDM's on ebay with the same part number (F7LF-9D370-AA), but they are both from a 97 Continental not a LSC. Any guesses if they are the same, or if the internal code/fuel trim is different? The OEM is discontinued. :(
The dealer can verify interchange.
 

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max at fivestar recently verfied the mark 8 fpdm is obsolete but is the same as a mustang except the bracket is different, you just put the new module on the old bracket
I believe he said they were 107ish dollars
 

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max at fivestar recently verified the mark 8 FPDM is obsolete but is the same as a mustang except the bracket is different, you just put the new module on the old bracket
I believe he said they were 107ish dollars
LOL. Yep, early yesterday morning, I spent over an hour working with Max on that very subject. :D

Ford is weird!! You have to buy the whole "assembly" which consists of the module and bracket. The bracket is vehicle specific, but the module pretty much isn’t. So the “assembly” with the Mark VIII bracket is discontinued, but the module without the bracket is not. Gee, maybe let the parts person look up the individual item…

And of course none of the numbers on the actually on the module indicate the actual assembly.

But just for anyone else’s reference:

Mark VIII FPDM Assembly: F7LF-9D370-AA (Discontinued)

Mark VIII FPDM Module: XS7F-9D370-BA (approx $100)
Which is the same for a Mustang (I think we looked it up for a 2001 GT Mustang)

Hoepfully it will be here by the end of the week and I can get the LSC back on the road. :znanner:
 

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Anyone? :2huh:

And for those with the supercharged Gen II's: Did you use the FPDM or did you bypass it and tune out the signals to/from the PCM?
I just found mine burntout and so was wondering if u ever found out about bypassing this...is there a way to run safely without the fpdm and if so how to bypass thanks
 
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