800 miles on my ‘22 AT4 and check eng light came on. Onstar says it’s P059F code. Dealer says something about active shutter in grill
Today GMC told dealer they don’t know why this error is on my truck.
Anyone else seen this yet?
Link wouldn't work, so here you go (BTW - time to find a more competent service department):
P059F Code - Active Grille Air Shutter 1 Performance
Code P059F Possible Causes
Check for debris obstructing the Active Grille Air Shutter
Faulty Active Grille Air Shutter
Active Grille Air Shutter harness is open or shorted
Active Grille Air Shutter circuit poor electrical connection
Faulty Engine Control Module (ECM)
How do I Fix the Code P059F?
Check the "Possible Causes" listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector's pins.
What are Code P059F Possible Symptoms?
Engine Light ON (or Service Engine Soon Warning Light)
Code P059F Description
The active grille air shutter system closes shutters in the front grille to enhance vehicle aerodynamics in driving situations where cooling and A/C loads are relatively low and high levels of front-end airflow are not required. If high levels of airflow are required, the active grille air shutter system will open one or both shutters. The control signal from the Engine Control Module (ECM), ignition, and ground circuits enable the active grille air shutter actuators to operate. If the conditions for opening the shutters are reached the ECM commands the active grille air shutter actuators to open one or both shutters. The dual active grille air shutter system consists of two aero shutter mechanisms located in the front grille for controlling the amount of air flowing through the grille. It includes three wires; ground, power, and a Local Interconnect Network (LIN) Bus serial data circuit from the ECM to the shutter actuator. The ECM determines shutter state based on various vehicle conditions such as vehicle speed, coolant temperature, fan state, refrigerant system pressure, A/C compressor state, and ambient temperature. The ECM has the ability to command each shutter individually to the open or closed positions through communications on the LIN Bus. The actuators are powered by an ignition circuit that is active when the key is in the RUN position. The vehicle may have to be driven for up to 13 minutes at speeds greater than 41 km/h (25 mph) before a shutter begins to move. If low ambient temperature is detected, the shutters will remain in the closed position. The Diagnostic Trouble Code (DTC) will be set if the desired Active Grille Air Shutter Position achieved has exceeded the number of attempts.
Code P059F GMC Tech Notes
The aero shutters on some 2019-2021 Silverado 1500, Tahoe, Suburban, Sierra 1500, Yukon, Escalade; 2020-2021 Silverado 2500HD/3500HD and Sierra 2500HD/3500HD models may have several conditions that could potentially cause improper shutter operation. Several DTCs may be set, depending on the specific conditions. When checking aero shutter operation, be sure to look for electrical integrity issues, displaced louvers/vanes, and debris that may block movement.
