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Matt, Engineer
Category: Infiniti
Satisfied Customers: 21989
Experience:  Honors degree in Mechanical Engineering, worked 8 years as a Formula 1 engine engineer.
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How to test an ecu on 93 infinity j30

Customer Question

How to test an ecu on 93 infinity j30
Submitted: 2 months ago.
Category: Infiniti
Expert:  Matt replied 2 months ago.


unless you have a signal generator and an a oscilloscope then its quite difficult to 'test' the ECU

what I'd suggest is the car isn't starting is to 1st check the ECU power is present by measuring voltage at the fusebox and on its relay socket

if there's 12V on the fuse with the ignition on then check to see if you're opening the fuel injectors, if the injectors are working you can hear them click - its difficult to hear them with background noise so use a long screwdriver like a stethoscope, placing the handle end in your ear and the metal tip against the body of the injector whilst your assistant turns the engine over.

and if this is all OK then I'd consider sending the ECU off for testing / repair

Customer: replied 2 months ago.
Were do i find the relay
Expert:  Matt replied 2 months ago.


the ECu power relay should be in the underhood fusebox, the underside of the lid should ID what relay is what

Expert:  Matt replied 2 months ago.

do you still need help?
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