Tesla has issued a new Service Bulletin regarding the rear lower control arms in 2012-2021 Model S and 2015-2021 Model X vehicles in Norway. The bulletin was issued earlier this week, and comes after Norwegian authorities investigated reports of these suspension parts failing, but ultimately decided not to force Tesla to issue a recall.
The Issue: Corrosion Risks from Water Ingress
According to the Service Bulletin, SB-25-31-002, a copy of which was obtained by Drive Tesla, the issue covers Model S vehicles built between 2012 and 2021, and Model X vehicles built from 2015 to 2021. Tesla says these vehicles may experience water intrusion into the rear lower control arms, potentially leading to corrosion and cracking, unwanted noises, suspension misalignment, and even affect the overall ride quality of the vehicle.
Inspection Process and Diagnosis
Tesla service technicians are advised to inspect the vehicle while it is lifted, checking for any signs of water leakage, salt deposits, or rust on the control arm plugs. If minor deposits are found but no significant corrosion is detected, the technicians will replace the plugs with new ones.
However, if rust or water damage is evident in the plug holes, the bulletin instructs technicians to replace both rear lower control arms entirely with newer, more robust versions. If replacement is necessary, both the left-hand (LH) and right-hand (RH) control arms must be replaced to maintain balanced suspension performance, Tesla says.
The Investigation
The Norwegian Public Roads Administration (NPRA) investigated the issue following more than a dozen customer reports in 2022 regarding rear lower control arms suddenly breaking. However, the agency determined that the failures primarily occurred at low speeds and while reversing, concluding that “a break in the rear lower control arm does not constitute an unacceptable risk.”
NPRA also noted that the number of reported cases was relatively low compared to the total number of Model S and Model X vehicles on Norwegian roads. As a result, it saw no justification for requiring a recall.
Tesla, for its part, told NPRA that the likelihood of a severe issue arising from rear lower control arm failures was minimal and would not pose a significant safety risk.
The investigation was concluded in January 2024, and now a year later Tesla has issued the Service Bulletin.
