P0177 Infiniti Fuel Composition Sensor Circuit Range/Performance
Possible causes
– Flexible Fuel (FF) sensor to Vehicle Power (VPWR) circuit harness open or shorted
– FF to VPWR circuit poor electrical connection
– Open in FF sensor signal circuit
– Short to ground in FF sensor signal circuit
– Fuel contamination
– FF to VPWR circuit poor electrical connection
– Open in FF sensor signal circuit
– Short to ground in FF sensor signal circuit
– Fuel contamination
Tech description
Replaced Fuel Composition Sensor
Symptoms
– Engine Light ON (or Service Engine Soon Warning Light)
P0177 Infiniti Description
Fuel Composition Sensors are used to determine the amount of ethanol alcohol in the gasoline. Normally, a gasoline engine should not have more than 10% ethanol alcohol in the fuel for proper operation. Some vehicles have a Flexible Fuel (FF) system on them that allow them to run on up to 85% ethanol alcohol in the fuel. The fuel composition sensor sends a frequency modulated signal to the engine controller which is proportional to the alcohol content of the fuel. The injector pulse width and the ignition timing are modified for the increased alcohol content. It takes almost twice the amount of alcohol compared to gasoline to produce the same power.
Infiniti Vehicle:Infiniti EX35,Infiniti FX35,Infiniti FX50,Infiniti G25,Infiniti G37,Infiniti M35,Infiniti M37,Infiniti M56,Infiniti QX562013 Infiniti,2012 Infiniti,2011 Infiniti,2010 Infiniti,2009 Infiniti,2008 Infiniti,2007 Infiniti,2006 Infiniti,2005 Infiniti,2004 Infiniti,2003 Infiniti,2002 Infiniti,2001 Infiniti,2000 Infiniti,1999 Infiniti,1998 Infiniti,1997 Infiniti,1996 Infiniti,