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Paul M ASE Master
Paul M ASE Master, ASE Master Tech
Category: Kia
Satisfied Customers: 4683
Experience:  ASE Master Tech 20+ Years
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2003 kia: relay located..My fuel pump..fuel pump fuse..ecu

Customer Question

Hello- i have a 2003 Kia sorento.. i would like to know exactly where is the MFI control relay located.. My fuel pump is not receiving the 12volts. i checked the fuel relay and fuel pump fuse and all is well.. if I can find this MFI control relay i can narrow the problem down from the ECU or the the MFI control relay.. Thanks in advance for your time.
Submitted: 6 years ago.
Category: Kia
Expert:  Paul M ASE Master replied 6 years ago.

Hello and thank you for using Just Answer


the MAIN relay PCM relay is in the underhood fuse panel


click here to view the location


let me know if you need more help



Edited by 2Paulm Ase Master Tech Kia Tech L1 on 11/20/2010 at 9:12 PM EST
Customer: replied 6 years ago.
So you are saying the MFI control relay is the same as the Main Relay...?
Expert:  Paul M ASE Master replied 6 years ago.

yes the MAIN relay is the EFI relay


there are also 4 fuses after the relay INJ , ECU , O2 UP , O2 DWN


they are all under the hood


turn the key on and check power to those 4 fuses if you have power to those fuses with KEY on the Relay is working



Customer: replied 6 years ago.
ok.. I know all of the relays under the hood in the compartment box are working... I guess my question is which relay will cause the voltage to be non-existant at the fuel pump and where is/are they located.. thanks for your quick answers..
Expert:  Paul M ASE Master replied 6 years ago.

the fuel pump gets power from the FUEL pump relay


the fuel pump relay is also in the relay panel under the hood


if you remove the fuel pump relay and turn the Key on you should have power to 2 of the PINS


the computer grounds one of the PINS to energize the relay


you need to test that you have power to 2 pins of the Fuel relay with key on..


if you do have power to 2 of the pins .. the computer is most likely not energizing the relay... the computer needs to see a crankshaft sensor signal to ground the relay


let me know if you have power to 2 of the pins at the fuel pump relay..



Customer: replied 6 years ago.
Hello paul.. just checked the voltage and there is 12 volts on 2 of the pins on the Fuel Pump relay..
Expert:  Paul M ASE Master replied 6 years ago.

ok one of two things is happening


either the PCM is not grounding the RELAY


or the FUEL CUT SENSOR is not allowing the power to run to the PUMP


the fuel cut sensor is in the right side of the engine compartment (Right front fender Area under the hood)


the wires to this reset switch are RED and YELLOW... see if the switch needs to be reset.


let me know





Customer: replied 6 years ago.
I reset that fuel cut sensor (a.k.a. inertia switch) numerous times... So is it safe to say that the PCM (ECM or ECU) is faulty? thanks for your time and quick responses
Expert:  Paul M ASE Master replied 6 years ago.

if the PCM has a bad power or ground input... or it does not see a signal from the Crankshaft sensor it will not energize the pump


did you test for power directly at the reset switch? both wires with key cranking?


there should be power to both RED and YELLOW for a few seconds when the key is first turned on..


also verify when you turn the ignition key on that the ENGINE light is coming on for the bulb test.


you also need to Verify you are getting an RPM signal while cranking... if there is no RPM signal the crankshaft sensor could be the problem... the PCM will not energize the fuel pump without RPM signal



Customer: replied 6 years ago.



Verified power checks for the inertia switch (red wire= o volts, yellow wire = 12 volts)


the engine light bulb do illuminate.


Not sure what a RPM signal is 9where should i look for this..

Expert:  Paul M ASE Master replied 6 years ago.

with the inertia switch plugged in do you get power to the red wire? whith key on for a second?


if you have power on the Yellow but nothing on the RED while cranking the inertia switch is bad



Paul M ASE Master and other Kia Specialists are ready to help you
Customer: replied 6 years ago.
Hey Paul Thanks for all your help.. if this check dont work.. i will continue my journey tomorrow..
Expert:  Paul M ASE Master replied 6 years ago.

Ok let me know how you make out