2024 Cadillac Lyriq electrical system problems

“My Cadillac Lyriq slams the brakes on when driving forward or in reverse with nothing in its path. This makes me very nervous to drive the vehicle as it is unpredictable as to when it happens. It scares me and affects my confidence in driving the vehicle. The entire vehicle also without warning goes completely dark meaning the screen and the entire vehicle just shut off.”

“My 2024 Cadillac LYRIQ, VIN [XXX], has a recurring 12V/electrical problem that has caused repeated battery failures and no-start conditions. At 4,716 miles, the vehicle would not start, the dash went black, and “Service Battery Fault” appeared. Cadillac tested the 12V battery, documented that it FAILED, and replaced it. Only 367 miles later, at 5,083 miles, the vehicle displayed “Electric Drive Unit Immediate Attention” and “Limiting Features to Save Battery.” Cadillac documented code U2C11 and performed BECM/Hybrid-EV Battery Pack Communication Module programming/reset. At 12,839 miles, Cadillac documented another electrical issue: the radio and display would not turn off after the vehicle was shut off. The system required reprogramming. At 16,040 miles, the LYRIQ again became completely inoperable and had to be towed to Cadillac. The dealer again documented that the 12V battery FAILED testing and had to be replaced for the vehicle to start. I am concerned that repeated battery replacement is treating the symptom rather than correcting an underlying electrical defect. A vehicle that repeatedly loses its low-voltage electrical system and becomes completely…”

“On or about August 6, 2026, I received email communication from the GM EV Concierge , establishing Case #106606137. My vehicle has been "bricked" and GM has had possession of it since August 3, 2026, (46 days and counting) without so much as an official diagnosis or repair timeline. I have repeatedly been told that the matter has been “escalated,” that GM is “working with the dealership,” and that the repair is being “expedited,” however, I don't know to whom it has been escalated, but at this point I have not received any measurable result rather than continuous general status statements. Regardless, the practical result remains undisputed: my vehicle continues to be unavailable, my vehicle has yet to receive an official diagnosis, and I have yet been provided with a reliable repair timeline. GM continues to route my vehicle through a process that has failed to produce an official diagnosis does not resolve the underlying problem. More importantly, it does nothing to address the fact that I remain without the leased vehicle I am paying for while it is under warranty. Because GM continues to possess my vehicle, I have been required to incur over $3,000.00 in…”

“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 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.”

“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…”