Nissan Repair: 2000 sentra 1.8 automatic, wouldnt start No SES light, fuel pump relay, jumper wire

Question
Hello, 2000 sentra 1.8 automatic, wouldn't start one morning. Would cracking but no start.  Then noticed the fuel pump would not run. With the key in the on position, there is no SES light. I hooked up a code reader and  it would not link up. i thought a bad ECM (ECU), bought a used one and but did not work.

There is no power at fuel pump but ground is there , the fuel pump relay does have power, but it is not reaching to fuel pump and no SES light.  Checked all fuse and they are working fine.  


do you think i need to check the ecm relay first ? but am having trouble finding it or what else should i do.  Car Crank but no start no fuel pump sound and no SES light.


Please help


Thanks,


Gill

Answer
Hi there, When you turn the ignition key to on position, there is power to the fuel pump for about 2 seconds and then it stops. The purpose of this is to  bring the fuel pressure to specs and prevent the fuel pump from running if the motor is not cranked. When you crank the motor to start it, there should be constant power to the fuel pump. Remove the fuel pump relay and locate the positive terminal of the relay on the relay block with the test light. there are 2 more terminals. One of them is the ground and the other one is the pump. With a small jumper wire, jump the 12V terminal and the pump terminal. If you accidentally jump it to the ground terminal it will spark so be careful! Now with the jumper cable in place, check the fuel pump  for power. If there is power, then the relay needs to be replaced. If there is no power, there is an open wire from the relay block to the fuel pump. Note that this test by passes the ECM. If there is no power to the relay block with the ign. key to on position, then we have an ECM problem. If the scanner tool does NOT communicate with the ECM, then the ECM has a problem somewhere. It can be an open/broken wire or the ECM have failed!