2024 Cadillac Lyriq

The vehicle is a Cadillac Lyriq. Following an over the air software update pushed by the manufacturer, the vehicle began displaying a high voltage system error message and lost the ability to DC fast charge. The high voltage components themselves are reported to be functional, the issue appears to be caused entirely by the software update rather than a hardware failure. The vehicle has been at an authorized dealership service center since August 14, 2026, awaiting a resolution. The dealership has confirmed the fault is present and is consistent with a known issue caused by the manufacturer's software update, but has not been able to repair it independently, since the fix requires a corrected software release from the manufacturer. As of this writing, the manufacturer has not issued the corrected update and has not provided a timeline for when one will be available. This creates a safety risk because the vehicle cannot be relied upon for longer trips or situations requiring DC fast charging, which can leave the driver stranded or unable to reach a destination or charging option within a safe range, particularly in hot weather conditions common in this region. The warning message and loss of fast charging capability appeared immediately after the software update was applied, with no prior symptoms. It is unknown whether the manufacturer has independently inspected this specific vehicle beyond the dealership's diagnosis. The high voltage system and charging hardware remain available for inspection upon request. Multiple other owners of this same model have reported the identical issue following the same software update, suggesting this is a widespread defect rather than an isolated incident.

On August 9, 2026, at approximately 3:40 a.m., while driving, the vehicle suddenly lost all propulsion and became completely disabled on the roadway. The vehicle remained powered on but would not move forward or backward. At approximately the time of the failure, Cadillac/OnStar Advanced Diagnostics generated a critical Electric Drive Unit warning instructing immediate service and reported diagnostic code P0A78. Additional vehicle diagnostic warnings involved the electric drive unit/high-voltage propulsion system. I immediately contacted roadside assistance but was unable to obtain a workable towing solution for several hours. The vehicle ultimately had to be privately towed and has remained undriveable since the incident. The loss of propulsion occurred unexpectedly while the vehicle was being driven, without advance warning that would have allowed me to safely plan for the vehicle to become disabled. I am concerned that the same sudden loss of propulsion could occur at higher speed, in traffic, at an intersection, or in another location where an unexpected loss of motive power could create a serious crash risk. The vehicle requires diagnosis and repair for the Electric Drive Unit/P0A78 condition.

The infotainment screen in my car plus the menu control went completely dead. With the screen dead completely this mean you cannot see the speedomoter, rear camera feeds, warning symbols on the dash. You cannot see current speed, you cannot hear any sound so all alerting systems are down. You are completely blind in a vehicle built around this screen. Dealership has already confirmed faulty computer module. However was told it would have been originally resolved under N252500680. It has only been inspected by the manufacture. No warnings, no nothing, just dead screen out of nowhere that requires new part to bring online. Meaning dead dead; part is currently on back order and design changes were made after this exact model year showing knowledge of the fault.

This is about an issue with the ACC system. While driving with the ACC engaged, it will intermittently disengage and without notification. Then the vehicle applies hard braking. After many multiple occurrences, I now tap the brake pedal and apply acceleration. I can't tell you how concerning this can be while driving at interstate speed. Just the thought of a large truck behind me will put the fear into you. Additionally, I have been able to hear an electrical clicking noise emitting from the left side of the steering wheel. When this occurs the ACC is unavailable and/or unable to be selected. A barrage of notifications will appear saying the Adaptive Cruise Control Selected or Cruise Control Selected. Our Lyriq has been in the shop for this problem at least 3 times. Everytime the outcome is CND or WAD

In the past 18 months the vehicle has experienced phantom breaking while driving 3 times. Each time there were no vehicles within 30 or more feet from the vehicle. All 3 times occurred while driving the vehicle and going between 20-40 mph. The vehicle engaged in an emergency break and stopped the car in the road. All three times could have resulted in a major accident as it occurred on busy roadways. This last time it happened in the middle of an intersection with no vehicles around me or behind me. This is a major safety concern and put my family and I in a potentially dangerous situation that could have caused major injuries to myself, my family and others around us. The vehicle is currently with Cadillac being inspected. During conversations with Cadillac they said this is a known issue and suggested that I turn the mechanism off and bypass the safety feature to avoid it from happening again. This is not a systematic fix. This is a bypass. We purchased the car for the safety and security and how sophisticated the safety mechanisms are and we have now been told as a suggestion to simply bypass it. This is very concerning on a national level of That the vehicle is known for doing this. We no longer feel safe in this vehicle The dealer has not confirmed if they have gotten it to duplicate. The only updates we have is that they are still working on the diagnostic testing. There were no warnings prior to the phantom breaking taking place.

Component Involved: Steering Wheel Assembly (Super Cruise Steering Wheel Light Bar / Rim)Safety Defect Description:The plastic insert covering the Super Cruise LED light bar and the surrounding leather wrap located directly on the top rim of the steering wheel are breaking apart, peeling, and separating. This is an immediate and severe driving safety hazard. While executing turns and maneuvering the vehicle, the driver’s hands and clothing sleeves are actively getting caught and snagged on the exposed, broken plastic edges and peeling wrap on the wheel rim. This causes physical interference and sudden, unexpected entrapment of the driver's hand or clothing during active steering.Consequences of the Defect:This defect presents an imminent risk of a vehicle crash due to sudden mechanical restriction of the driver's hands. If a driver’s sleeve or fingers become trapped or snagged by the peeling steering wheel trim while negotiating a sharp turn, curve, or emergency evasive maneuver, they will be unable to smoothly rotate the wheel, leading to a direct loss of steering control.

I put the car in reverse and released the parking brake. The car started to move backwards. However, the back passenger door was wide open, and the passenger was standing outside the car in the path of the open door. The door hit a guide wire running from the top of a power pole to the sidewalk beside the car. The wire pulled the door backwards, destroying it. This was fortunate. Without the wire in the way, I would’ve had not heard the crashing of the door and would have continued to drive over the person standing beside the car as the passenger door knocked him down. The indicator that the door was still open is so small on the gauge cluster that I couldn’t see that the door was still open when I put the car into reverse. There was no audible warning that I was about to move before all doors were closed, and the emergency braking didn’t stop the car from moving. The passenger’s leg got pushed sideways under the open door. Had the guidewire not pulled the door backwards and caused so much noise that I stopped, the door would’ve broken the passenger’s leg and potentially pushed him under the rear passenger side tire.

What component or system failed or malfunctioned, and is it available for inspection upon request? The issue involves the Anti-lock Braking System (ABS) and the transition between regenerative braking and friction braking in my Cadillac Lyriq (RWD). The ABS engages unexpectedly during normal braking conditions when using one-pedal driving. The vehicle is available for inspection upon request. How was your safety or the safety of others put at risk? The unexpected ABS activation creates inconsistent and unpredictable braking behavior, including a pulsing sensation and reduced braking confidence. This affects the driver’s ability to modulate braking smoothly and predict stopping distance, increasing the risk of a collision, especially in normal traffic conditions where consistent braking response is critical. Has the problem been reproduced or confirmed by a dealer or independent service center? Yes. The issue has been reproduced during multiple visits to authorized Cadillac dealerships. However, I have been told that the vehicle is “operating as designed,” despite the abnormal braking behavior. Has the vehicle or component been inspected by the manufacturer, police, insurance representatives or others? The vehicle has been inspected by multiple authorized Cadillac dealerships and the issue has been escalated to General Motors. No resolution or fix has been provided to date. Were there any warning lamps, messages or other symptoms of the problem prior to the failure, and when did they first appear? There are no warning lights or messages associated with this issue. The problem occurs intermittently during normal driving conditions, particularly when transitioning from regenerative braking (one-pedal driving) to applying the brake pedal. The issue began shortly after taking delivery of the vehicle and has persisted since.

My 2024 Cadillac LYRIQ generated the following High Voltage Battery fault codes via On-Demand Diagnostic: U2B4A, U2B4D, U2B50, U2B53, U2B56, U2B59, U2B5C, U2B5F, U2B62, U2B65, U2B68 — all under module VIC - Lithium-Ion Battery. Multiple codes are flagged "Service Right Away" indicating an active fault in the high voltage propulsion battery system. I brought the vehicle to Lindsay Cadillac, Alexandria VA [XXX] ) on [INSERT DROP-OFF DATE]. As of today [INSERT TODAY'S DATE], the vehicle has been sitting at the dealership for [X] days with ZERO repair action taken. The service manager has stated he does not know what to do, has no timeline, and cannot provide any answers. GM Technical Service Bulletins PIP6009B and 25-NA-044 specifically cover these exact DTCs and provide a documented repair procedure. The dealer has failed to follow or initiate this procedure. No loaner vehicle was provided despite this being a warranty repair on inoperative vehicle. I have been forced to rent a vehicle at $125/day out of pocket. I have an open Cadillac Concierge case number [93707662 #]. Cadillac Concierge was unable to reach the dealer's service department by phone. I have escalated in writing to GM's executive office including [XXX] and [XXX] with no resolution. This is a high voltage battery fault on an all-electric vehicle flagged as "Service Right Away" severity. The vehicle remains unrepaired, the dealer is unresponsive, and GM's own customer service cannot reach the dealer. This represents both a safety concern and a complete failure of the warranty service obligation. I am requesting NHTSA investigation of both the underlying battery defect and the dealer's failure to act on a known TSB. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

The vehicle has experienced repeated failures of the infotainment and display system, including the screen going blank and displaying “no content available” while functions such as Apple CarPlay are actively in use. The issue affects the ability to control media and view system information from both the main display and steering wheel controls. The vehicle has undergone multiple repair attempts, including replacement of the human machine interface (HMI) module and radio module, as well as repeated programming. Despite these repairs, the issue continues to reoccur, including immediately after the most recent repair. The condition is intermittent and difficult to duplicate, and a field service engineer has been unable to consistently reproduce the issue. The dealership has indicated there may not be a current fix and that resolution could depend on a future software update. This ongoing failure of critical display and control systems raises safety concerns and has not been resolved despite multiple repair attempts.