General Motors is under intensifying federal scrutiny as the National Highway Traffic Safety Administration (NHTSA) expands two separate investigations covering more than 2 million vehicles. The probes target a brake-by-wire system that can fail while driving and a 6.2-liter V8 engine plagued by bearing failures — issues that have triggered hundreds of complaints, dozens of crashes, and at least six injuries.

The investigations come at a critical time for GM, which is betting heavily on electric vehicles and needs to maintain consumer trust in its safety systems. While the two issues are technically distinct, together they paint a picture of an automaker grappling with quality control across its most important product lines.

Brake-by-Wire Investigation: eBoost Failures

NHTSA's Office of Defects Investigation (ODI) has upgraded its review of GM's eBoost brake system after receiving 227 incident reports — a number that swells to 745 when GM's own data is included. The system, which uses a motor-driven pump to provide brake boost, can suffer a spindle fracture while driving. GM maintains that in such a failure, the vehicle retains antilock brakes, traction control, and stability control until it stops. But NHTSA says many drivers report immediate loss of braking, creating a crash risk.

The problem affects more than 1.1 million vehicles, including several of GM's electric models and vehicles produced for Honda and Acura. According to NHTSA documents, the agency has confirmed 22 crashes and six injuries across five crashes, though no fatalities have been reported. The investigation covers model years that include popular EVs like the Chevrolet Bolt EV and EUV, as well as internal-combustion models like the Cadillac CT6.

We have received multiple reports indicating that the eBoost failure leads to an immediate loss of braking capability, contrary to the manufacturer's stated safety redundancies,

a NHTSA official said.

6.2-Liter V8 Engine Failures Draw Fresh Scrutiny

Separately, NHTSA is investigating the 6.2L V8 engine used in nearly 1 million trucks and SUVs, including the Cadillac Escalade, Chevrolet Silverado, and GMC Sierra. The engine has been subject to prior recalls, but the fix itself is now under investigation after engines continued to fail. The probe focuses on connecting rod and bearing failures that can lead to engine seizure or, in some cases, fire.

Source: The investigation was expanded after owners reported repeated failures even after repair work was completed. The 6.2L V8 is a high-performance engine option that is also offered in the GMC Yukon and Chevrolet Tahoe. The Escalade, which starts at $91,100, is particularly affected, and GM has faced criticism for the way it has handled replacement parts availability.

Escalade and Other Affected Models

The Cadillac Escalade is the most expensive vehicle caught up in the engine probe, but the 6.2L V8 is widely used across GM's full-size truck and SUV lineup. The engine's issues have led to a rapid increase in warranty claims, and some owners report being stranded when their vehicles suddenly lose power. NHTSA has received dozens of complaints, and the agency's move to expand the probe suggests the problem may be more widespread than initially estimated.

Broader Recall Landscape

This year has seen an unprecedented number of engine-related recalls across the industry. From Ford to Hyundai, automakers have recalled millions of vehicles over manufacturing defects. According to industry analysts, the rise in engine failures is linked to tighter emissions standards and the push for more powerful yet fuel-efficient powertrains, which have led to increased stress on internal components.

The GM investigations highlight a growing regulatory focus on critical safety systems, particularly as vehicles become more electrified and software-dependent. The eBoost system is an example of brake-by-wire technology that replaces traditional hydraulic boosters, and it is expected to become more common in future EVs.

What's at Stake for GM

GM says it is cooperating fully with NHTSA and has issued fixes for both problems, but the agency's decision to expand its investigations indicates that unresolved questions remain. If NHTSA determines that either defect poses an unreasonable safety risk, it could force a recall that would be far more costly than the voluntary ones GM has already conducted.

For GM, the stakes are high. The company is investing billions in electric vehicle production and has set ambitious sales targets. A pair of high-profile safety probes could erode consumer confidence at a time when the company is trying to position itself as a leader in automotive technology. Safety advocates argue that these investigations reveal a need for stricter oversight.

The fact that we're seeing multiple probes into the same automaker suggests a systemic issue that goes beyond isolated manufacturing errors,

said Sean Kane, an auto safety consultant. He noted that GM has a history of recalls, including the ignition switch scandal that led to over 100 deaths and billions in penalties. While the current issues have not been as deadly, they underscore the importance of robust safety management.

For now, owners of affected vehicles are left in limbo, waiting for GM and NHTSA to determine whether a broader recall is warranted. In the meantime, NHTSA recommends that drivers who experience brake failure warnings or engine knocking contact their dealer immediately. The outcome of these investigations could reshape how GM handles safety issues in the era of software-defined vehicles.