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GMC · Known Issues

2025 GMC Hummer EV Problems: 3 Known Issues

2025 model year · NHTSA recalls, manufacturer TSBs, and owner forum reports · Updated September 2026

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Issue summary

According to Au7o's research across NHTSA recalls, manufacturer TSBs, and owner forum reports, the 2025 GMC Hummer EV has 3 documented known issues, with 1 rated critical. The most serious is 12-Volt Auxiliary Battery Drain Leaves the Truck Completely Dead While Parked ($0-$450 repair). DIY maintenance guides at au7o.io.

In This Article

  • Hummer EV Electrical1
  • Hummer EV Safety/Recalls1
  • Hummer EV Suspension1
  • Recalls5
  • FAQ
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In This Article

  • Electrical1
  • Safety/Recalls1
  • Suspension1
  • Recalls5
  • FAQ

All 3 Known Issues

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ALL YEARS20262025202420232022

On the 2022-2025 GMC Hummer EV, one of the most frequently reported real-world failures on the Hummer EV Pickup is parasitic drain on the 12V auxiliary battery, which leaves an otherwise fully charged truck totally unresponsive - no doors, no screens, no ability to shift or start. Two mechanisms drive it. First, the truck does not always fully power down when the driver walks away: owners report having to press the start/stop button on exit or the vehicle stays awake, and a key fob left near the truck repeatedly wakes it. Second, several body and propulsion modules shipped with calibrations that drew excessive current from the 12V system, and the vehicle only polls 12V state roughly once a day, so it does not catch the decline in time to top the battery up from the high-voltage pack. Owners have documented trucks going dead after sitting six days in a garage at 90% state of charge and unplugged. Secondary symptoms once voltage sags include a "conditions unable to shift" error and assorted software malfunctions that clear after a 12V jump.

Common Symptoms

  • Truck completely dead and unresponsive after sitting several days
  • Doors will not unlock, screens will not power up
  • "Conditions unable to shift" error message
  • Random software malfunctions that clear after a 12V jump
  • Will not accept a charge when plugged in while the 12V is flat
  • Vehicle stays awake after the driver exits

How to Fix

The dealer-side fix is a full module reprogramming sweep: GM bulletin PIT6065E directs technicians to update all vehicle modules, which includes calibrations specifically changed to reduce 12V draw. Ask for that by number rather than accepting a single module flash. Short term, a 12V jump on the under-hood remote terminals will wake the truck, after which the DC-DC converter recharges the auxiliary battery from the HV pack. Behavioral mitigations owners rely on: press the power button before exiting, keep the fob well away from the truck when parked, and leave the truck plugged in when stored. A cheap Bluetooth 12V battery monitor is the standard forum recommendation for catching the decline early. If drain persists after PIT6065E, the auxiliary battery itself should be load-tested and replaced under warranty.

Typical repair cost:$0 - $450

Research This Issue

GoogleRedditYouTubeNHTSA
Community Reported
Medium ConfidenceVerifiedReviewed Aug 2026

On the 2022-2025 GMC Hummer EV, hummer EV Pickup owners report that Super Cruise, a headline feature of the truck, works inconsistently - repeatedly refusing to engage on the same stretches of interstate and tollway where it worked before, and dropping out mid-drive. The dash messaging varies between "Super Cruise Not Available" and "No Road Information." Two distinct causes appear in owner reports and dealer diagnosis. The first is connectivity: the system depends on the OnStar/AT&T data connection to pull map and GPS correction data, and in weak-coverage areas it will not arm; owners describe being bounced between GM, OnStar and the dealer with each blaming the others, and some trucks needed the Super Cruise activation/subscription state fixed on the back end before the feature would work at all. The second is the module itself - dealers have applied a Super Cruise module software update under bulletin 24-NA-143, and in some cases replaced the Super Cruise module outright and reflashed it to the newest patch, which resolved the dropouts.

Common Symptoms

  • "Super Cruise Not Available" message on mapped highways
  • "No Road Information" message
  • Super Cruise disengages unexpectedly mid-drive
  • Super Cruise icon never turns green
  • Feature missing entirely after delivery (activation not provisioned)

How to Fix

Start by confirming the Super Cruise subscription/activation state is actually provisioned on the account - a meaningful share of "it never worked" cases are back-end provisioning, not hardware. Then have the dealer apply the Super Cruise module software update per GM bulletin 24-NA-143 and update all related modules. If dropouts persist on roads that are confirmed to be in the mapped LiDAR network, the remedy that has worked is replacing the Super Cruise module and flashing it to the latest calibration - a warranty repair. Note that Super Cruise legitimately will not engage on unmapped roads, in construction zones, with obscured lane markings, or when the driver-attention camera is blocked, so rule those out before treating it as a defect.

Typical repair cost:$0 - $1,500

Research This Issue

GoogleRedditYouTubeNHTSA
Community Reported
Medium ConfidenceVerifiedReviewed Aug 2026

On the 2022-2025 GMC Hummer EV, gM bulletin PIT6144G documents 2022-2025 GMC Hummer EV owners reporting that the air leveling suspension stops working, with a "Service Leveling System" message in the driver display and DTC C1197 SYM92 stored in the automatic level control module. On a truck that weighs over 9,000 pounds and relies on the air springs for both ride height selection (including Extract Mode and off-road heights) and automatic load leveling, a dead compressor leaves the vehicle stuck at a fixed height and unable to compensate for payload. GM identifies two causes: a plugged or pinched air inlet hose feeding the air suspension compressor assembly, and a software condition in the automatic level control module. Separately, owners have documented rear dampers losing fluid after moderate off-road use - one 2024 pickup took two months at the dealer to diagnose a right-rear damper leak, which was then covered under warranty. Fitting oversize (38-inch) tires has been reported to destabilize the system further and is not a supported configuration.

Common Symptoms

  • "Service Leveling System" message in the driver information center
  • Air suspension will not raise or lower
  • Vehicle stuck at one ride height
  • Extract Mode and off-road height settings unavailable
  • Rear of the truck sags under load
  • Bouncy, uncontrolled ride (leaking damper variant)

How to Fix

Have the dealer follow PIT6144G. The first step is inspecting the air inlet hose to the compressor assembly for a pinch or blockage and clearing/rerouting it; if the hose is clear, the remedy is a software update to the automatic level control module. Both are warranty repairs on a truck inside the 3-year/36,000-mile bumper-to-bumper term. If ride quality is bouncy or uncontrolled rather than the height being stuck, that points at a leaking damper instead - have the dampers inspected for fluid loss, which is also a warranty item. Do not chase this with aftermarket compressor parts before the bulletin has been run; the inlet-hose cause is cheap to fix and commonly missed.

Typical repair cost:$0 - $1,800

Research This Issue

GoogleRedditYouTubeNHTSA
Community Reported
High ConfidenceVerifiedReviewed Aug 2026
NHTSA Recalls5 recalls

SEAT BELTS:FRONT:ANCHORAGE

General Motors, LLC (GM) is recalling certain 2023-2024 GMC Hummer EV pick up, 2024 GMC Hummer EV SUV, and 2024 Chevrolet Silverado EV vehicles. The left or right front seat belt buckle attachment bolts may not be tightened properly.

Campaign #23V78600022/11/2023

ELECTRICAL SYSTEM:WIRING

General Motors, LLC (GM) is recalling certain 2024 Cadillac Lyriq, Chevrolet Blazer EV, Chevrolet Silverado EV, GMC Hummer EV SUV, and GMC Sierra EV vehicles. The electric motors in the rear drive units may have insufficiently insulated wires that can contact each other, resulting in a loss of drive power.

Campaign #24V32000009/05/2024

ELECTRICAL SYSTEM:PROPULSION SYSTEM:TRACTION BATTERY

General Motors, LLC (GM) is recalling certain 2022 BrightDrop EV600 and 2022-2023 GMC Hummer EV Pickup electric vehicles. The high voltage battery pack enclosure may not be properly sealed, allowing water to enter the pack.

Campaign #22V77100013/10/2022
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Other GMC Models

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Frequently Asked Questions

What are the most common GMC Hummer EV problems?

According to Au7o's research across NHTSA recalls, manufacturer TSBs, and owner forum reports, the 2025 GMC Hummer EV has 3 documented issues. The most frequently reported are: 12-Volt Auxiliary Battery Drain Leaves the Truck Completely Dead While Parked, Super Cruise Intermittently Unavailable or Drops Out on Previously Mapped Roads, Air Ride Adaptive Suspension Inoperative with "Service Leveling System" (DTC C1197). Of these, 1 is rated critical and should be addressed promptly.

Is the GMC Hummer EV reliable?

The 2025 GMC Hummer EV has 3 known issues compiled from NHTSA recalls, manufacturer TSBs, and owner forum reports. 1 issue is rated critical: 12-Volt Auxiliary Battery Drain Leaves the Truck Completely Dead While Parked. Prospective buyers should inspect for these issues and factor potential repair costs into their purchase decision. Regular maintenance following the manufacturer's schedule helps prevent many common problems.

How much does it cost to fix common GMC Hummer EV problems?

Repair costs for known GMC Hummer EV issues range from $0 to $1,800, depending on the specific problem and whether you choose DIY or professional repair. The most critical issue, 12-Volt Auxiliary Battery Drain Leaves the Truck Completely Dead While Parked, typically costs $0-$450 to repair. Au7o provides step-by-step DIY maintenance guides that can help reduce repair costs.

What is the 2022-2025 GMC Hummer EV 12-Volt Auxiliary Battery Drain Leaves the Truck Completely Dead While Parked?

One of the most frequently reported real-world failures on the Hummer EV Pickup is parasitic drain on the 12V auxiliary battery, which leaves an otherwise fully charged truck totally unresponsive - no doors, no screens, no ability to shift or start. Two mechanisms drive it. First… Repairs typically run $0-$450. Severity: high.

What is the 2022-2025 GMC Hummer EV Super Cruise Intermittently Unavailable or Drops Out on Previously Mapped Roads?

Hummer EV Pickup owners report that Super Cruise, a headline feature of the truck, works inconsistently - repeatedly refusing to engage on the same stretches of interstate and tollway where it worked before, and dropping out mid-drive. The dash messaging varies between "Super Cru… Repairs typically run $0-$1,500. Severity: medium.

Content on this page was compiled with AI assistance using NHTSA complaints, TSBs, owner reports, and public automotive data. While we strive for accuracy, this information may contain errors. Always verify repair procedures and specifications with your vehicle's service manual or a qualified mechanic.

Data compiled from NHTSA recalls, manufacturer TSBs, automotive forums, and AI-assisted research. No aggregated owner-report counts available for this vehicle yet.

EXTERIOR LIGHTING:TAIL LIGHTS

General Motors, LLC (GM) is recalling certain 2022 GMC Hummer EV vehicles. Taillight software can cause one or both rear taillights to become inoperative, or remain fully or partially illuminated. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle Safety Standard number 108, "Lamps, Reflective Devices, and Associated Equipment."

Campaign #22V14100010/03/2022

ELECTRICAL SYSTEM:PROPULSION SYSTEM:TRACTION BATTERY

General Motors, LLC (GM) is recalling certain 2022 GMC Hummer EV and 2023 Cadillac Lyriq vehicles. Certain connections within the high-voltage battery pack may be out of position or incorrectly welded, which can cause a loss of drive power.

Campaign #23V36700025/05/2023

Enter your VIN at NHTSA.gov to check recalls specific to your vehicle.

What is the 2022-2025 GMC Hummer EV Air Ride Adaptive Suspension Inoperative with "Service Leveling System" (DTC C1197)?

GM bulletin PIT6144G documents 2022-2025 GMC Hummer EV owners reporting that the air leveling suspension stops working, with a "Service Leveling System" message in the driver display and DTC C1197 SYM92 stored in the automatic level control module. On a truck that weighs over 9,0… Repairs typically run $0-$1,800. Severity: medium.