Luxury car manufacturer Mercedes-Benz AktienGesellschaft has recalled over a million vehicles following the discovery of an emergency call system fault.
A glitch uncovered in the eCall feature means alerts sent from the car to emergency services in the event of an accident may contain incorrect information regarding the vehicle's location.
The software-related bug impacts 1,292,258 cars in the United States manufactured from 2016 through 2021. Among the vehicles affected are the A-, B-, C-, E-, GT-, S-, SL-, and SLC-class; CLA- and CLS-class; and G-, GLA-, GLB-, GLC-, GLE-, and GLS-class.
According to the defect report issued by the National Highway Traffic Safety Administration (NHTSA), "either an authorized Mercedes-Benz dealer or an over-the-air (“OTA”) update will update the software of the communication module for the automatic emergency call system on the affected vehicles.
"All customers will be mailed recall notification letters as required under federal regulations. For vehicles with a 'Mercedes Me' subscription service, the software update will be performed OTA and so a dealer visit is not required."
Mercedes in the UK told the BBC: "This software update will also be implemented in other countries and we are in close contact with the local authorities."
An investigation into the fault was launched by Mercedes in October 2019 after the eCall center reported a single instance in Europe of the automatic eCall system relaying an inaccurate vehicle position.
Mercedes found that it had no record of the eCall system behaving in a similar way during any of its internal testing, including during vehicle crash tests in various scenarios.
"MBAG began to work closely with the supplier in different test environments and tried to replicate and understand the event," wrote the NHTSA.
"In depth analysis of the potential behavior of the power supply and the communication module eventually found how the software design of the communication module affected the relay of location information for the single European case."
No reported incidents of the eCall system's sending incorrect location data have been recorded in the United States. Updated software in the production process from January 29, 2021, ensures that the fault can no longer occur.