Some customers who own a 2021- through 2023-model-year Chevy Tahoe or Chevy Suburban equipped with air leveling suspension (RPO code F47) may notice that their SUV has a low or leaning suspension, or that the air leveling function is inoperative. Now, a possible cause behind this issue has been identified, as has a related fix.
According to a recent report from GM TechLink, affected units of the Chevy Tahoe and Chevy Suburban may display “Service Leveling System” in the Driver Information Center display. Additionally, several Diagnostic Trouble Codes (DTCs) may be triggered in the Air Leveling Control Module, while other DTCs seemingly unrelated to the air leveling suspension may be triggered as well, such as 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).
Furthermore, using the GM GDS2 (Global Diagnostic System 2) to perform a Short Term Inflate function may not work, even though the GDS2 screen indicates that it is indeed working. According to the GM TechLink report, these issues may be the result of a communication loss with a power window motor, or a door ajar issue. These conditions are apparently more common in up-fitted vehicles.
According to the report, GM technicians are instructed to check for any loss in communication or door ajar DTCs. In order for the air leveling suspension to properly operate, the door ajar status should show that the doors are closed. Each door ajar switch is hardwired to the related door window motor, and if there is a DTC triggered for loss of communication with a door window motor, the door ajar status will not be reliable and the GDS2 door ajar parameter will default to closed.
The report indicates that techs must open and close each door to ensure that the door position matches the related GDS2 parameters. Once repairs are performed on possible door ajar DTCs or a loss of communication with a door window motor, GM techs should then reassess the air suspension issue.