Some GMC Yukon owners may notice that their SUV’s air leveling suspension system (RPO code F47) no longer functions, or that it exhibits a low or leaning suspension condition. Now, a possible cause for this issue has been identified, and with it, a fix to be performed by GM technicians.
Per a recent report from GM TechLink, these issues may be present in GMC Yukon models between the 2021 and 2023 model years, and may also include the message “Service Leveling System” displayed in the Driver Information Center.
In addition, this issue may trigger several different Diagnostic Trouble Codes (DTCs) that may or may not seem related to the air leveling suspension, including U0222 (Lost Communication with Front Side Door Window Regulator Motor – Driver), U0223 (Lost Communication with Front Side Door Window Regulator Motor – Passenger), U0224 (Lost Communication with Front Side Door Window Regulator Motor – Passenger), and U0225 (Lost Communication with Rear Side Door Window Regulator Motor – Right). When using the GM Global Diagnostic System 2 (GDS2) to perform a Short Term Inflate function, the GDS2 screen may indicate that the function is working, even though in reality it is not.
According to the GM TechLink report, these issues may be the result of a communications loss with a power window motor, or a door ajar issue. These conditions are more common in up-fitted vehicles.
To address this issue, GM technicians should first check for a communications loss or door ajar DTC. The air leveling suspension in the GMC Yukon requires that the door ajar status indicate that the doors are closed in order to work properly, and each door ajar switch is hardwired to the related door window motor. If a DTC is triggered for communication loss with a door motor, the door ajar parameter will default to closed, even though the actual status is unknown. As such, GM techs should open and close each door to ensure that the door position matches the related GDS2 parameters. Following any possible repairs on door ajar DTCs or communication loss with a window motor, the air suspension issues should be reassessed.