jose2015

Hi fellow Lexus owners can anyone help me locate the circuit opening relay for the fuel pump on my 92 SC4OO much obliged . Thanks

gerrb

iTrader: (34)

Not sure if I am understanding you well but if your question is Pump Controller... the fuel pump ecu is on the side panel behind the driver seat, that in turn is controlled by your Car ECU.

jose2015

there is an EFI relay before the fuel pump ecu and an circuit opening relay that runs the EFI to run the fuel pump

SC400slide

iTrader: (11)

The EFI main relay is in the relay/fuse box in the engine compartment. There is a diagram located on the underside of the lid that will show you exactly where it is.

jose2015

I know, what i need is the circuit opening relay that feeds the EFI relay found under the hood

Ali SC3

iTrader: (10)

whats the symptoms. usually don't have to mess with the COR. normally what goes bad is the fuel ecu, but if you are getting no 12V whatsoever anywhere in the car the check out the COR and the M-REL.
if you are getting 12v and the pump is just not turning on, then try jumping +B and FP on the diagnostic connector. if they fuel pump comes on then probably a bad fuel ecu.

jose2015

We have installed new pump everything is good except power to the EFI relay which is supplied from the circuit opening relay if I give the EFI direct pwr the car will run but you turn it off and on , back to same problem,now the EFI relay get its on pwr from the circuit opening relay just can't find it some say it's a relay next to the engine ECU/ECM ??

SC400slide

iTrader: (11)

If you're not getting power to the fuel pump, check the 30 amp fuse for the injectors.

Ali SC3

iTrader: (10)

check the M-REL wire at the ecu or if you did any wiring around there. that is the signal wire that turns on the whole efi system unless I am remembering incorrectly.

COR is part number 5 "28300" according to this diagram, not positive if its correct though.
http://www.lexussouthatlantaparts.co...=0&modelYear=0

jose2015

Well guys and gals looks I need an ECM for my fuel pump problem does anyone know where one can be had for a reasonable price ? also what year models would work mine is a 92

6SOARER

iTrader: (20)

Classified section, hit up Aliga. He can get you just about anything for your SC.

jose2015

Does anyone have or can tell me how to get the wiring diagram for a 92 SC400 ECM for pin routing

Ali SC3

iTrader: (10)

lextreme has them
http://www.lextreme.com/misc.htm

jose2015

Lextreme only show the ECU diagram I need the ECM diagram