How do I get to this fuel pump ECU ?

 

i had a similar issue...

mine would start up, and then it would sound like its msfiring then die... itll do it for like 10 mins if i keep trying to start it... as the temp gauge and engine starts to warm up from trying to start... it eventually fires up just fine....

when i was driving the car would die every once in a while... then once it completely died and never fired up again... just crank... then it threw a code for the fuel pump ecu.

if you think its the pump ecu one easy way to test is in the diagnostic port jump the Fp and the +b (the the left top and left bottom if youre standing in front looking to the rear)

jump that leave it in then try starting... this bypasses the ecu and if it fires up perfect its the ecu (i have 2 extra by the way)

my issue was this and a distributor problem... the distributor is what caused my car not to stay on... the cam sensors inside were gone.. the fuel pump ecu just went out at the end

 

Those ports aren't on the diagnostic plug. Is this the one thats under the hood?

 

Hope this helps:
(This is for SC400, but I think the SC300 fuel pump ECU would be at the same location)

 

Well, I did the FP and B+ jump and the car started like its never started before... I guess I found my problem huh? Is it possible, to jump the fuel pump to and from work for a few days while I secure a new Fuel Pump ECU? I figure, by jumping it its just a secondary power source that just activates the pump and over rides the ECU. What do you guys think? I HAVE to have a working car lol.

 

I unplugged my batter for about 20 minutes and putting it back which resets the ECU as well.... I think this will help. My car used to idle low, and now that I did that, it idles around 900-1000 now. before it used to idle at like 500.

 

So can I leave the Fuel Pump ECU jumped?

 

Yea... No one knows?

 

I am having the same Issue with one of my sc300's. Anyone have a idea how much a fuel pump ECu will cost?

 

i think its called the 12 volt mod for fuel pump. search for that and see what comes up.

 

i did this with mine...

you pull the back driver panel out... and wire the green and black/red wire together...

this bypasses the ecu...

ive tried like 3 different fuel pump ecu and dont know whats wrong. when the car warms up its fine but still dies every once in a while. and in know that not all 3 fp ecu's are bad.

so i just wired the gren abd black together... been working perfect since

 

Dont you lose MPG that way since your upping the volts to the fuel pump?

 

The only electronic parts I can find on my 94 sc 400 in the back driver side quarter panel are the attena motor and a small box which has "Lamp Failure" written on it. Is this the fuel ecu?

 

The only two elec. parts on the rear drivers side panel I can find are the attenna relay and lamp failure sensor. There are several wire sets coming off the top of the fuel tank. One has a bright yellow sheathing and goes over the top of the fuel tank and down in front which makes it pretty inaccessible and the other is wrapped in black tape and goes up into the rear dash panel, I guess it is for the high center brake light.
I did the jump test of Fp to B+ and the engine started and ran fine. Pull the jumper the engine sputters and dies. Put jumper back in and starts and runs fine.

I FOUND IT. Did a search for 12v mod and there it is. Got the little fellow out but unfortunately Toyota dealer does not have the part number so either must buy a new one or do the 12v mod. I guess it depends on how much the fuel ecu costs.

Called both Lexus dealerships price is 346.46. Looks like the 12v mod is it unless I can find this thing for around $150.

Went ahead and did the 12v mod. Starts as soon as turn the key, idles smooth. Thanks for all the help especially Maeve and Yumasc300.