Fuel pump used during cranking

[Tipo874]

Which fuel pump, 1 or 2, is used during key on engine off and then during cranking? I am getting a code P1237 only after the engine has cranked and started.
There is a long crank of a few seconds needed to start. Also if I have a shorted or open circuit as reported by the code, then how does the engine start at all?

Thanks, David

 

[twobjshelbys]

Did you check the fuses? If a pump is truly down then you could pull the #1 fuse. If it doesn't start it means #2 is also down. If it starts like it did before but doesn't when #2 fuse is pulled, then #1 is broken.

There are also relays. As I recall the fuel pump relays are the same as another one (A/C?) Try swapping the fuel pump relays one at a time with another non-fuel pump relay to see if you have a bad relay.

 

[Tipo874]

Thanks! It starts now and runs with both pumps connected but takes a long crank. Then pump #1 is the pump used 1st for prime and then crank when it has a problem then the computer switches to pump #2?
I am calling fuel pump #1 the one connected thru connector 1489 in the wiring diagram.

The car starts and runs with either fuel pump plugged into FPDM 2. It appears that FP2 is the start and run fuel pump circuit.