Honda Engine Restart Failures Under Federal Investigation

Over 2 Million Vehicles Affected by Auto Idle Stop Defect

The National Highway Traffic Safety Administration (NHTSA) has launched a sweeping investigation into more than 2 million Honda and Acura vehicles following widespread complaints about a critical engine restart defect. This issue centers on the Auto Idle Stop (AIS) system—a fuel-saving feature that shuts off the engine at a complete stop and restarts it automatically when the driver lifts their foot off the brake.

However, for thousands of drivers, the engine fails to restart, leaving vehicles immobilized in traffic. Some owners report needing a jump-start to resume driving. If you are a California resident experiencing this defect, your vehicle may qualify for protection under California’s Lemon Law.

Which Honda and Acura Models Are Being Investigated?

According to the NHTSA, the following models are included in the ongoing federal investigation:

This investigation impacts approximately 2,209,466 vehicles nationwide. Honda owners in California should pay particular attention, as persistent AIS failures may trigger California Lemon Law protections—especially if multiple repair attempts have failed to resolve the issue.

What’s the Issue with the Auto Idle Stop System?

The Auto Idle Stop system is designed to improve fuel efficiency by shutting off the engine during short stops, such as red lights or traffic congestion. The engine is intended to seamlessly restart when the brake is released.

Unfortunately, reports submitted to the NHTSA reveal that:

• The engine fails to restart after stopping, leaving the vehicle stalled.
• Drivers may need to shift into Park and manually restart the engine.
• In some cases, jump-starting the vehicle is required.
• These failures can occur without warning.

While not all restart failures are safety-related, the California Lemon Law may still apply if the defect substantially affects the vehicle’s use, value, or safety.

As of March 2025, the NHTSA has received 1,384 reports related to this issue. According to FOX News, the NHTSA has received allegations of four incidents that may have involved crashes or fires, with two reports of injuries.

Source: LiveNOW from FOX, based on NHTSA preliminary evaluation released March 26, 2025.

Honda’s Response: Service Bulletins and Unresolved Complaints

Honda issued technical service bulletins (TSBs) in early 2023 in an attempt to address AIS restart failures with software updates and component replacements. Despite these efforts, complaints continue.

The NHTSA stated:

“ODI continues to receive complaints of AIS failure to restart, with many complainants alleging the campaign countermeasures had been completed.”

In other words, even owners who have followed Honda’s repair guidance may still be driving vehicles with unresolved defects—potentially making them candidates for a Lemon Law buyback in California.

Real-World Impact: What Honda Drivers Are Experiencing

Here are two real-world scenarios that illustrate the impact of the defect:

Scenario 1: Intersection Stall

A 2022 Honda Odyssey driver stops at a red light in Los Angeles. When the light turns green, the vehicle fails to restart. The driver shifts into Park, holds up traffic, and attempts a manual restart—only to find the engine unresponsive. A tow and jump-start are required.

Scenario 2: School Pickup Panic

A 2023 Acura MDX owner experiences an engine failure mid-school pickup line. Even after receiving Honda’s software update, the vehicle fails to restart. The incident leads to a missed pickup and another costly dealership visit.

These cases highlight how defects can impair the use, value, or safety of affected vehicles.

Do You Qualify for California Lemon Law Protection?

California’s Lemon Law—officially the Song-Beverly Consumer Warranty Act—provides strong protections for consumers stuck with defective vehicles. If your Honda or Acura continues to experience restart problems after repair attempts, you may qualify for compensation.

Qualifying conditions include:

• Multiple Repairs: The dealership has made several unsuccessful attempts to repair the engine restart failure.
• Substantial Defect: The defect substantially impairs the use, value, or safety of the vehicle.
• Vehicle Downtime: The vehicle has been in the shop for more than thirty days cumulative.
• Under Warranty: The vehicle was brought in for repair while the vehicle was still under the manufacturer’s warranty.

What Remedies Are Available Under California Lemon Law?

If your vehicle qualifies, you may be entitled to:

• Refund: Reimbursement for the purchase price, registration fees, and taxes.
• Additional Compensation: Recovery of costs such as towing, rental vehicles, and lost income.
• Vehicle Replacement: A comparable vehicle free from defects.
• Attorney Fees Covered: If your case is successful, the manufacturer pays your legal fees—you pay nothing out of pocket.

Why This Investigation Matters for California Consumers

A stalled vehicle in traffic is not just an inconvenience—it can increase the risk of accidents and cause significant stress and financial burden.

This investigation underscores the importance of California Lemon Law, which holds manufacturers accountable and protects drivers from unsafe or unreliable vehicles.

Take Action Today: Consult Gayle Law Group, PC

At Gayle Law Group, PC,California Lemon Law attorney Liz Gayle brings over 25 years of experience helping consumers recover compensation for defective Honda and Acura vehicles. If your vehicle qualifies, you may be entitled to a refund or replacement—with zero out-of-pocket legal fees.

Don’t wait—delays can jeopardize your eligibility under California’s revised Lemon Law deadlines.

Learn more about California Lemon Law for Honda vehicles here.

Is your Honda a lemon? Contact Gayle Law Group, PC today for a free consultation and let us help you pursue the resolution you deserve.