[FIXED]Crank / No Start 2007 Ford Taurus

Already checked for Fuel, Spark and RPM signal. Only thing missing is fuel pressure at the rail. My question is, while checking the Fuel Pressure Driver Module FPDM I found that I had no duty cycle signal on the FP_M wire (DG/Y) with either the KOEO or while cranking. Another thing is the fuel pump ground wire BK/PK is only dropping to .9v while cranking. Any ideas on this before I switch out the FPDM. Thanks

did you check for power on the pk/bk wire from the inertia switch??

Sorry, you know how I love my wiring diagrams.



Seeing .9V on the pump ground isn't so unusual on this system, because it FPDM still uses a pulse width control even during cranking. It's not a complete ground, and your meter reflects this. The fact that it IS pulling down to .9V is possibly a good sign for the FPDM, as it shows it's trying to run the pump. This capture of a similar FPDM shows the pump control used during cranking.



Are you positive there was no activity on the FP_M wire? I ask because it's a pretty slow compared to most square wave signals. Here's a shot of the FP command signal in red, and the FP_M signal in blue.



A complete cycle takes one second, so your DMM might struggle to recognize it as a duty cycle.

Since it looks like the FPDM is controlling the pump, I'd suggest checking the pump feed, white red. It should be steady B+ any time the key is on or cranking. If you find power, then I'd suspect the pump itself. You can confirm this by wiring a headlight or other substitute load across the pump power and ground terminals at the FPDM.

Thanks for the quick responses. All the power and grounds checked out. Put an amp probe on the ground side of the pump and while cranking I'm reading a 15amp draw. Assuming the FPDM checks out the only other thing would be the fuel pump, is this correct?

jcsloan wrote: Thanks for the quick responses. All the power and grounds checked out. Put an amp probe on the ground side of the pump and while cranking I'm reading a 15amp draw. Assuming the FPDM checks out the only other thing would be the fuel pump, is this correct?

Agreed. 15A is quite a bit for one of these pumps, so it makes me suspect a pump mechanical fault, or a kinked fuel line. Either way, I think your FPDM is doing well, and you're good to do a pump.