Mercedes-Benz Issues Safety Recall for High-Performance AMG Plug-In Hybrids: What Owners Need to Know

In a significant safety development for the high-performance automotive sector, Mercedes-Benz has officially initiated a recall campaign affecting nearly 3,000 of its most sophisticated plug-in hybrid (PHEV) vehicles. The recall centers on a critical software malfunction that poses a potential risk of a sudden loss of drive power, a defect that strikes at the heart of the reliability expected from the luxury brand’s flagship performance division.

The recall, identified by the National Highway Traffic Safety Administration (NHTSA) under campaign number 25V129000, impacts a wide range of AMG E Performance models produced between the 2023 and 2025 model years. As Mercedes-Benz continues to pivot toward electrified performance, this technical setback highlights the increasing complexity of integrating high-voltage hybrid powertrains with advanced vehicle control software.

Main Facts: The Scope of the Recall

The recall impacts 2,943 vehicles currently registered within the United States. These vehicles are among the most technologically advanced in the Mercedes-AMG portfolio, utilizing complex E Performance hybrid systems designed to bridge the gap between traditional combustion engines and electric-only efficiency.

Affected Models:

The list of impacted vehicles spans the entirety of the AMG E Performance lineup, including:

• 2023-2025 AMG S 63 E Performance
• 2023-2025 AMG GT 63 S E Performance (4-Door Coupe)
• 2024-2025 AMG GT 63 S E Performance (2-Door Coupe)
• 2024-2025 AMG SL 63 S E Performance
• 2024-2025 AMG GLC 63 S E Performance (both SUV and Coupe variants)

At the core of the issue is a software error located within the starter motor and generator control unit. Under specific, yet-to-be-fully-defined operating conditions, the control unit may fail. Should this failure occur while the vehicle is in motion, it could result in a sudden loss of drive power, significantly increasing the risk of a collision. While the vehicle’s braking and steering systems are typically designed to remain operational even during power-train failures, the loss of propulsion in heavy traffic or at high speeds creates a hazardous environment for both the driver and surrounding motorists.

Chronology: From Initial Reports to Official Action

The path to this recall began not with a widespread failure, but with isolated reports of technical malfunctions that triggered internal investigations within the Stuttgart-based automaker.

Late 2024: The Discovery Phase

Mercedes-Benz first became aware of potential inconsistencies in the starter/generator control software in the final quarter of 2024. The initial reports were relatively benign, with owners noting that their vehicles occasionally failed to start. While a "no-start" condition is inconvenient, it does not immediately suggest a safety-critical defect in a moving vehicle.

However, as engineering teams began to dissect the software logs and performance data from these specific vehicles, they discovered that the underlying logic error within the control unit was more pervasive than initially thought.

January – February 2025: The Risk Assessment

Over the early months of 2025, Mercedes-Benz conducted an extensive internal audit of the E Performance powertrain architecture. The engineering team identified that the software error could, under certain stress conditions, trigger a full shutdown of the starter-generator management system. Because the AMG hybrid system is deeply integrated—using the electric motor to assist the combustion engine—a failure in the control unit can interrupt the seamless transfer of power, leading to the aforementioned loss of propulsion.

February 28, 2025: Official NHTSA Filing

Recognizing the safety implications, Mercedes-Benz submitted a formal recall notification to the NHTSA on February 28, 2025. This filing marked the formal transition from an internal quality monitoring process to a public safety mandate, ensuring that all owners of the nearly 3,000 affected vehicles would be notified and provided with a standardized remedy.

Supporting Data: Understanding the E Performance Architecture

To understand why this recall is significant, one must appreciate the engineering complexity of the AMG E Performance powertrain. Unlike standard hybrids that prioritize fuel economy, the AMG system is designed for "power-dense" performance.

The system utilizes a 400-volt battery pack and an electric motor mounted on the rear axle, coupled with a high-performance twin-turbocharged V-8 or four-cylinder engine. The starter-generator acts as a crucial bridge, managing the high-voltage energy flow and ensuring that the combustion engine and electric motor can synchronize instantaneously.

The software control unit for this system is essentially the "brain" of the hybrid drivetrain. It manages:

1. Energy Recovery: Controlling how kinetic energy is captured during braking.
2. Torque Fill: Using the electric motor to provide instantaneous torque while the turbochargers spool up.
3. Power Distribution: Balancing the load between the internal combustion engine and the high-voltage electric motor.

When this "brain" experiences a software crash, it defaults to a safety mode. In the case of the affected AMG models, the default mode is a shutdown of the motor unit to prevent further electrical damage, which—unintentionally—strips the vehicle of its forward thrust.

Official Responses and Remediation

Mercedes-Benz has moved quickly to establish a clear protocol for owners. The company emphasizes that while the risk of a collision exists, it has received no reports of accidents, injuries, or fatalities related to this software defect.

The Remedy

Mercedes-Benz dealers will perform a software update on the starter motor and generator control unit. This update is designed to patch the logic error, ensuring that the control unit remains stable during high-demand scenarios.

• Cost: The service is entirely free of charge to the vehicle owner.
• Timeframe: The update is a relatively straightforward procedure, though owners are encouraged to schedule an appointment with their local authorized AMG service center to ensure the software flash is performed correctly and the system is recalibrated.

Owner Notification

The company has confirmed that it will begin sending notification letters via mail starting April 29, 2025. Owners who do not wish to wait for the letter can proactively check their vehicle’s status. By visiting the Mercedes-Benz Recall Portal and entering their 17-digit Vehicle Identification Number (VIN), owners can immediately confirm if their specific vehicle is included in the campaign.

For further assistance, owners can contact the Mercedes-Benz customer service hotline at 1-800-367-6372.

Implications: The Growing Pains of Automotive Electrification

This recall serves as a microcosm of the challenges facing the entire automotive industry. As luxury manufacturers rush to electrify their high-performance divisions, they are moving from a world of mechanical reliability to one of software-defined performance.

The Software-Defined Vehicle Paradigm

The "Software-Defined Vehicle" is the current industry goal, where hardware is standardized and performance is dictated by code. While this allows for OTA (Over-the-Air) updates and constant improvement, it also introduces the risk of "bugs" that were previously unheard of in the purely mechanical era. A recall for a software update is now just as common as a recall for a faulty brake pad or a loose bolt.

Maintaining Brand Reputation

For a brand like Mercedes-AMG, which trades on a reputation for precision engineering and "One Man, One Engine" craftsmanship, a software-based recall can be particularly sensitive. The E Performance lineup represents the future of the brand; ensuring these vehicles are reliable is essential for maintaining consumer confidence in the transition away from internal combustion engines.

Future Outlook

The swift nature of this recall—where the manufacturer identified the issue, investigated it, and proposed a solution without waiting for a string of reported accidents—is a sign of a maturing regulatory and corporate compliance culture. In the modern era, proactive safety disclosures are the gold standard for maintaining trust.

For owners of the AMG S 63 E Performance, GT 63 S, SL 63 S, and GLC 63 S, the advice is clear: do not ignore the upcoming notification. While the defect is unlikely to manifest in day-to-day driving, the nature of a software-induced power loss makes it unpredictable. By prioritizing the software patch, owners can ensure their vehicles continue to deliver the world-class performance for which the AMG badge is renowned.

As the automotive landscape continues to evolve, the integration of complex electrical systems will remain the primary technical hurdle. Mercedes-Benz’s handling of this recall suggests that while the industry is encountering new types of challenges, the commitment to safety remains as rigorous as ever. Owners are encouraged to stay informed and utilize the official channels provided by the manufacturer to ensure their vehicle remains at peak, safe performance levels.