Q&A

 Master

I have an '01 Pathfinder, too. It's been a great car. The Service Engine Soon light is a Check Engine Light (http://repairpal.com/check-engine-light). There's something amiss in the emission control system, and I recommend taking it to a good diagnostic tech. I've had this problem--it was an evap system issue. Sometimes you can have problems with the ignition coils, too.

Not sure about the radiator fan. I'd bet you need to change either the assembly or the motor.

 Master

The cooling fan on the Pathfinder is a viscous coupling fan clutch.If the fan clutch assembly fails the fan "locks up" and drags making a loud sound all the time particularly on acceleration. A failed fan clutch decreases fuel economy due to drag on the engine.

 Rookie

I had the check engine light on and was told my engine had sludge and it had clogged a sensor. I changed the oil once a month and changed to Shell gas 93 octane, the light went out on its on. Thanks Shell Gas.

 Enthusiast

The shop manual for the Nissan Pathfinder states that you can clear the OBD II DTC (Diagnostic Trouble Code) (which will turn off the Service Engine Soon light on the dash) either by using the Consult II diagnostic scanner tool or by disconnecting the battery for at least 24 hours.

It is not recommended to do this, however, until after you have resolved the engine control malfunction which set the light (and the DTC) on in the first place.

Even if you cleared the DTC and turned the light off, after similar conditions were encountered which set them on in the beginning, are encountered again, two times in succession, the DTC will be stored again and the light will turn on again.

If the engine control problem which set the DTC and light on no longer exist, the computer will turn the light off after several driving trips, provided those same conditions are not encountered again.