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How to check if ECU is bad 1994 Impreza

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Hi,

 

Is there any simple way of checking if the ECU is bad on an EJ18 Impreza 1994?

Fuel pump is not getting power, so it is either the ecu or fuel relay.

 

 

any help appreciated

Info shows that power to the pump comes from SBF-2 in the panel under the hood and runs to the fuel pump relay. I suggest you check for power there first. At the relay, power comes from the fuse on a yellow wire and ties to a blk/red wire that goes to the pump. You should have 12 volts on both wires when the pump is supposed to be on if the relay is working ok. If that is good then there is either a bad wire connection between there and the pump wire (wire color turns to blue/yellow at the pump end), the pump is bad, or the ground wire to the pump isn't making good connection. There are at least a couple more connections to the pump after the relay so the trouble may be in one of those.

  • Author

thanks Cougar, I really appreciate all the help!

 

Checked for power on SBF-2, around 2.7v on and off key position.

Checked for power at the green plug relay connector 12.7 off, 12.4v on.

 

And there was around 12v at the pump connector when I last checked it.

 

And there was around 12v at the pump connector when I last checked it.

 

Did you also test the ground continuity at that connector? If so and it was good then bad pump, otherwise possibly not grounded well.

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