LGf Signal

The IGf signal is generated by the igniter on EFI/TCCS systems. The ECU supplies a 5 volt reference through a pull-up resistor to the lGf signal generation circuit in the igniter. When a spark plug fires, the IGf signal generation circuit pulls the five volts to ground, causing a pulse to be sensed at the ECU. One pulse is generated by the igniter for each ignition event which is carried out.

The IGf signal confirms that ignition has actually occurred. In the event of a failure to trigger an ignition event, the ECU will shut down injector pulses to protect the catalyst from flooding with raw fuel. Typically this failsafe shutdown occurs within eight to eleven IGt signals after the IGf signal is lost. This condition can occur with any primary ignition system fault, an igniter failure, a problem with the IGf circuit wiring, or with a faulty ECU.

Igf Wire For Ignition Systems
Do It Yourself Car Diagnosis

Do It Yourself Car Diagnosis

Don't pay hundreds of dollars to find out what is wrong with your car. This book is dedicated to helping the do it yourself home and independent technician understand and use OBD-II technology to diagnose and repair their own vehicles.

Get My Free Ebook


Responses

  • Albertina
    Can igt signal be used for injector pulse?
    10 months ago

Post a comment