P059F is a relatively common OBD2 trouble code on Nissan-made vehicles, such as the Nissan Pathfinder. If you have this code, your vehicle is equipped with an active grille shutter system.
The active grille shutter system only lets air through the grille when needed, reducing your the drag coefficient at higher speeds.
P059F in the Nissan Pathfinder indicates that the active grille shutter system is not operating correctly. Before doing anything else, check the grille to make sure that nothing is jammed up there.
If the active grille shutter system is stuck open, it’s not a breakdown risk. But, if it’s stuck closed, there’s a danger you can overheat the engine when driving the vehicle.
How Your Pathfinder’s Active Grille Shutter System Works
The active grille shutter system is designed to reduce drag and increase fuel efficiency. It does this by blocking the grille opening at high speeds. It will open if the coolant or oil temperatures pass a certain threshold (usually 203°F for the coolant).
Start-Up Diagnosis
Each time you drive a Nissan Pathfinder equipped with the active grille shutter system, it runs a self-diagnostic to verify that it can open and close properly.
The grille shutter always opens when the ignition is turned off. The next time the vehicle is turned on, the powertrain control module will command it to close. It then immediately opens back up and the self-diagnostic is complete.
If it fails this self-diagnostic test, O059F will be stored in your Pathfinder’s internal memory, and the check engine light will come on.
Nissan Pathfinder P059F Symptoms
Whether or not the active grille shutter system is opened or closed will change what symptoms you should expect to experience with P059F.
- Overheating (shutter stuck closed)
- Decreased Fuel Economy (shutter stuck open)
- Check engine light
The loss in fuel economy will be marginal at best.
Nissan Pathfinder P059F Causes + Diagnosis
Here is a solid diagnostic order for diagnosing P059F in the Nissan Pathfinder, as well as the most common causes for this code:
Debris
The first thing you should do if you have P059F is check the grille for debris. It is very common to pick something up on the road that’ll wedge in there that’ll keep the grille from opening or closing.
In the wintertime, snow can get into the grille and turn to ice. If you happen to be reading this when it hasn’t been above freezing out for a while, an iced grille is a real possibility.
Snow, trash, and even leaves are enough to bind the shutter.
Check For Technical Service Bulletins
OK, if there doesn’t appear to be anything binding the grille shutter, it’s time to start diagnosing the active grille shutter system.
With P059F, check to see if there is a Technical Service Bulletin relating to this problem for your Tacom’s model year.
TSB’s are notices that manufacturers provide that detail common problems and common solutions with vehicles they make.
There are quite a few sites for looking them up online. Otherwise, you can call your dealer and ask them to look it up for you.
Shutter Harness Wiring Problem
The wiring harness going to the active grille shutter control actuator could be opened or shorted. Due to its location at the front and bottom of your Pathfinder, it can take damage more than a typical wiring harness.
Look for burnt, frayed, broken, or otherwise damaged wiring. Make sure the connector pins are corrosion-free.
Bad Active Grille Air Shutter Actuator
If the wiring harness checks out, and the grille is debris-free, it’s time to suspect the actuator. The active grille shutter actuator is what physically opens and closes the grille.
With a good scan tool, you can command it to open and close. If it fails to do so, it likely needs replaced.
Conclusion
There are a few reasons that P059F can occur in the Nissan Pathfinder. You should always start by inspecting the grille. Good luck!