A blue Model S that's part of the Tesla recall.

Tesla is recalling Model S sedans built before April 2016 because power steering bolts may experience corrosion, especially in very cold climates, the automaker announced to owners through an email Thursday.

“We have observed excessive corrosion in the power steering bolts, though only in very cold climates, particularly those that frequently use calcium or magnesium road salts, rather than sodium chloride (table salt),” Tesla said in the email to owners.

The announced recall is reportedly the biggest ever for Tesla, which is a relatively young company. But the problem cited is a fairly common one in the auto industry, and the number of vehicles involved is relatively small, by industry standards. 

The automaker said it plans to replace all early Model S power steering bolts worldwide in case the cars might later wind up in “a highly corrosive environment.”

Tesla says there have been no injuries or accidents connected with this component.

The recall comes at a time when Tesla is facing scrutiny over a fatal California crash. Federal regulators from National Highway Traffic Safety Administration and the National Transportation Safety Board are beginning investigations into the crash that killed the driver of a Model X SUV when his vehicle ran into a highway safety barrier near Mountain View, Calif.

Tesla said in a blog post that it is cooperating with the agencies.

“We are currently working closely with the authorities to recover the logs from the computer inside the vehicle,” the blog post reads. “Once that happens and the logs have been reviewed, we hope to have a better understanding of what happened.”

The Details

Vehicles recalled: 123,000 Model S sedans worldwide. This recall does not affect either the Model X SUV or the Model 3 sedan, the automaker says.

The problem: Power steering bolts may undergo corrosion in very cold climates. If the bolts fail, the driver will still be able to steer the car, but increased force will be required because of lost or reduced power-steering assist. This can make the car harder to drive at low speeds and for parallel parking, Tesla says, but it shouldn’t affect driver control at high speeds.

The fix: Tesla will replace the bolts for free, and told owners in its email that it will contact them to schedule an appointment when parts are available in their region. The retrofit work will typically take around an hour. The automaker said owners can continue to drive their cars while waiting to get the fix made.

How to contact the manufacturer: Model S owners with questions can call 844-248-3752 or email ServiceHelpNA@tesla.com.

NHTSA campaign number: There is no NHTSA number yet.

Check to see whether your vehicle has an open recall. Plug in the 17-digit vehicle identification number at the National Highway Traffic Safety Administration's website. It will tell you whether your vehicle has any open recalls that need to be addressed.

CR members can stay up to date on their car recalls using our Car Recall Tracker.