P059F is a relatively common OBD2 trouble code on Nissan-made vehicles. If you have this code, your vehicle is equipped with an active grille shutter system.
The active grille shutter system lets air through the grille only when needed, reducing your vehicle’s drag coefficient at higher speeds. Nissan P059F indicates that the active grille shutter system is not operating correctly.
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 The 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-made vehicle 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, P059F will be stored in your vehicle’s internal memory, and the check engine light will come on.
P059F Symptoms
Whether or not the active grille shutter system is opened or closed will change what symptoms you should expect with it.
- Overheating (shutter stuck closed)
- Decreased Fuel Economy (shutter stuck open)
- Check engine light
The loss in fuel economy will be marginal at best.
Nissan P059F Causes + Diagnosis
Here is a good diagnostic order for P059F, 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 grill 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, there are a lot of TSBs for different model years.
Technical service bulletins 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 the vehicle, 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. You should always start by inspecting the grille. Good luck!