Oro

After some minor work last night, car would not start. 2002 ES300.

After lengthy diagnosis, I have no voltage at the fuel pump (either key "ON" or when cranking). Fuel pump runs on bench connected to 12V source. There is voltage at the relay, and I tried swapping the relay w/the identical horn relay to no effect.

I am trying to figure out what could cause this. I found this laundry list at a fuel pump sight (FuelPumpU.com):

Armed alarm system or anti-theft device
Blown fuse
Faulty fuel pump relay
Lack of RPM signal
Lack of oil sender signal
Tripped inertia switch
Faulty fuel pump control module
Faulty ignition switch
Faulty fuel press sensor
Faulty vane type air flow sensor

Can anyone make some suggestions? I had removed the rear seats to get at the upper strut mounts to re-tighten one that worked loose after new struts last weekend. I test drove the car after tightening. Drove perfectly. Re-installed back seat then no-start.

I removed the side passenger seat belt reels to make getting the seats out easier, and to get clear access to the upper mounting bolts. Also back there under the c-pillars are side curtain airbags and also an ABS module.

Could I have done something inadvertently to send a fault signal to the ECU/PCM?

I have tried pulling the fuses to it to get it to re-set (no joy) and I have no CEL or codes.

Stumped.

Chuckinnj

Broken wire or disconnected plug........ Reseat all plugs in the rear seat area where you were working.

Oro

Yep, I got it trying that gambit right after I posted.

There's a pair of white wire connectors that are not visible. They are behind the lower door opening trim on each side. One side got loose - hard to see how since they clip together. Might have been loose prior then fell out as the seat brushed it being re-installed. It has I think the sensors from the side airbags so that cut the fuel signal from the ECM.

ES300NZ

....which relay?, there are two, the fuel pump relay and the open circuit relay.

Oro

I swapped both the relays when I was testing - the EFI and the OCN... (whatever it's called)/labeled. 1st and 3rd relays front to back. I read that if the EFI was bad, it would not pass voltage to the OC relay so you need to test both if a relay is suspect.

My cause was the the (I think) air bag sensor in that wire bundle that mysteriously disconnected. But I did learn a lot about the wiring and PCM inputs so it was not a complete waste of time.

My loyal assistant supervised from her usual position but had no really helpful insights...

ES300NZ

oh well, don't feel to bad. I spent $600 chasing a MAF fault I caused myself by 'over cleaning' the sensor. It took months to fix/trace, and it frustrating as heck.