2023 GMC Sierra Problems – Engine, Electrical, and Transmission Defects

The 2023 GMC Sierra is marketed as a premium full-size pickup designed for durability, towing, and everyday reliability. However, a growing number of owners have reported serious mechanical and electrical problems that undermine those expectations. Many of these issues persist despite repeated dealership repair attempts, raising concerns under California’s Lemon Law.

This article explains the most common 2023 GMC Sierra problems, how they present in real-world driving, and what owners should do if their truck continues to fail under warranty.

What’s the Problem

Owners of the 2023 GMC Sierra have reported a pattern of defects involving the engine, electrical systems, and drivetrain. These are not cosmetic concerns or minor inconveniences. In many cases, the issues affect vehicle safety, reliability, and the ability to use the truck as intended.

Some Sierra owners report sudden engine failure or loud internal knocking. Others experience electrical malfunctions that interfere with vehicle controls, instrument displays, or tailgate operation. Transmission complaints include hesitation, harsh shifting, and shuddering that does not resolve after service visits.

When these problems repeat or keep the vehicle out of service for extended periods, the truck may qualify as a lemon under California law.

Engine Issues

One of the most serious complaints involves engine reliability. Some 2023 GMC Sierra owners report sudden loss of power, stalling, or internal engine noise that worsens over time. In certain cases, engines have required major internal repairs or full replacement well before expected service life.

Engine problems of this nature can pose safety risks, particularly if power is lost while driving at highway speeds or while towing.

Electrical System Failures

Electrical issues are another recurring concern. Owners have reported instrument cluster failures where critical information disappears or becomes unreadable. Others describe tailgate malfunctions, including unexpected opening or failure to respond to commands.

Electrical defects can be especially frustrating because they often appear intermittently, making them difficult for dealerships to duplicate or permanently repair.

Transmission and Drivability Complaints

Some drivers experience rough or delayed shifting, hesitation during acceleration, or shuddering while driving. These symptoms may continue even after software updates or mechanical adjustments. When drivability problems interfere with normal operation, they can significantly reduce confidence in the vehicle.

Recall / TSB

Certain 2023 GMC Sierra trucks have been subject to recalls and technical service bulletins related to engine components, braking systems, lighting, and electrical functions.

A recall typically indicates a safety-related defect recognized by the manufacturer, while a Technical Service Bulletin (TSB) provides guidance to dealerships on known problems that may not rise to the level of a formal recall.

The existence of recalls or TSBs can be important in a lemon law case, particularly when a known defect continues despite multiple repair attempts.

Symptoms

Owners experiencing problems with the 2023 GMC Sierra commonly report:

Engine

  • Knocking or ticking noises

  • Sudden stalling or shutdown

  • Loss of power or hesitation

  • Engine replacement under warranty

Electrical

  • Blank or malfunctioning instrument cluster

  • Tailgate opening or failing to latch properly

  • Warning lights appearing without explanation

  • Infotainment or system resets

Transmission / Drivetrain

  • Harsh or delayed shifting

  • Shuddering during acceleration

  • Hesitation when engaging gears

  • Ongoing drivability complaints after service

If these symptoms return after repairs, or if the dealership is unable to provide a lasting fix, lemon law protections may apply.

How to Proceed

Document Issues

  • Keep detailed notes of all symptoms, including when they occur and how they affect drivability.

  • Make sure every complaint is written clearly on the repair order when you drop the vehicle off.

Reasonable Number of Repair Attempts

  • While the law does not set a fixed number, repeated repair attempts for the same problem — often four or more — can support a lemon law claim.

  • Extended time out of service can also qualify, even if the issue changes slightly over time.

Monitor Symptoms

  • If you notice new engine noises, warning lights, or loss of power, stop driving and seek inspection immediately.

  • Continuing to drive with serious defects can worsen damage and complicate repairs.

Talk to a Lemon Law Attorney, like Valero Law

  • If your 2023 GMC Sierra continues to have unresolved problems under warranty, a lemon law attorney can evaluate whether you are entitled to a buyback, replacement vehicle, or cash settlement.

Call Valero Law

If you own or lease a 2023 GMC Sierra that continues to suffer from engine, electrical, or transmission problems despite repeated repair attempts, you may be entitled to relief under California’s Lemon Law.

Compensation may include:

  • Repurchase of your defective vehicle

  • Replacement with a comparable truck

  • Or a cash settlement for the diminished value and inconvenience

Call Valero Law, APC for a free lemon law case evaluation. We handle cases on a contingency basis — meaning there is no cost to you unless we win.

Joshua ValeroGMC, GMC Sierra, GMC Lemon Law, General Motors Lemon Law