EFI Fuse blow out?

Tiny
TONYLOVE1990
  • MEMBER
  • 2003 TOYOTA COROLLA
  • 4 CYL
  • 2WD
  • AUTOMATIC
  • 14,500 MILES
While driving the car it turned off and will not start. The EFi fuse was burned out. I was told it was the fuel pump. I replaced the fuel pump and the EFI fuse, but the EFI fuse continues to burn out and the car will still not start. Any thoughts on what is wrong?
Saturday, November 7th, 2009 AT 9:31 PM

5 Replies

Tiny
STEVEW84
  • MECHANIC
  • 673 POSTS
Well, that fuse supplies power to a lot of loads. MAF, Vent valve, purge valve, vapor pressure sensor, both 02 heaters, fuel pump. What you need is a good wiring diagram and starting unplugging things that are on that circuit.
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Saturday, November 7th, 2009 AT 9:46 PM
Tiny
THEMASTERMECHANIC
  • MEMBER
  • 1 POST
Hello, I thought I would post this, since I found the solution for mine. Long story short, it was the Idle Air Speed Control Valve.

My 2003 Toyota Avalon kept on blowing the EFI #2 fuse. I tried looking up the diagram and apparently, there are quite a few things that route to this fuse.

1.) Fuel Injectors, 2.) Mass Airflow Sensor, 3.) Oxygen Sensors (there are three of these), 4.) EVAP System, 5.) Throttle Position Control System, and 6.) Engine Control System.

What I have tried: Unplugging all Oxygen Sensors, unplugging the Mass Airflow Sensor, replacing the ECU, replacing the Fuse Box, unplugging the Fuel Pump, unplugging one Fuel Injector at a time, and unplugging all EVAP solenoids I could identify. But nothing worked. I thought I had unplugged all electrical components on the engine, and maybe blew 30 fuses to test. I even followed the wires to see if there could be a short somewhere. I did not remove the air box at the time, so I thought, might as well try to follow the wires with a tester (CEN-TECH Cable Tracker from Harbor Freight). That did not work either. I then prayed and asked God to help me find it, so I could move on with other things in my life. I later decided to take off the throttle body and the intake manifold, to see if perhaps a wire shorted back there. As I was going through it, I unplugged a couple of electronic components on the throttle body, and for some reason, I went back into the car to try and start it. Something new lit up when I turned the key to the on position, it was the Check Engine light. So, I went ahead and cranked the engine, and the car started up. I looked around to see what I could have nudged or unplugged. And when I plugged back in the Idle Air Speed Control Valve, the fuse started to blow again. But when I unplugged it again, the fuse stopped blowing and the car started up once more.

I really hope that this helps someone. It took me several days to figure this out. I was really considering giving up, called the car a lemon, and was contemplating selling it to a junk yard. But God helped me, so I wanted to post my story out there on a few forums and hope that it can help someone else out too. May God bless you.
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+4
Monday, July 11th, 2022 AT 12:15 PM
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 42,883 POSTS
This will definitely help others. Excellent addition to this thread! Please feel free to use 2CarPros anytime!
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Monday, July 11th, 2022 AT 1:56 PM
Tiny
KANGROUNDHERE
  • MEMBER
  • 1 POST
TheMasterMechanix, Bro You saved the day! Have a fantastic day today knowing that you help me tremendously just as you wanted to do by posting your comment.
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Saturday, September 16th, 2023 AT 6:34 AM
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 42,883 POSTS
Yep, that is some good info, glad it helped you. Use 2CarPros anytime, we are here to help. Please tell a friend.
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Monday, September 18th, 2023 AT 10:41 AM

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