Most common 2004 Hummer H2 problems
Share of the 59 complaints; one complaint can involve more than one system. "~" is the median mileage when the problem started.
Hummer H2 complaints by model year
Best H2 years: 2008, 2007, 2006. Years to avoid: 2003, 2005, 2004. Compare all years →
2004 Hummer H2 recalls (3)
Seat belts › Rear/other
On certain crew cab pickup trucks and sport utility vehicles, the 2nd row center occupant seat belt routing May make it difficult to position the lap portion of the safety belt low around the hips of occupants, especially smaller occupants, seated in this position.
Remedy: Dealers will cut open the guide loop, remove a portion of the loop, and then the remaining two sides should be folded over and secured with a retainer free of charge. The recall began on July 21, 2005.
Service brakes, hydraulic
Certain trucks, sport utility vehicles, and vans equipped with Bosch hydro-boost brake assemblies, the hydraulic brake booster pressure accumulator May crack and separate from the hydro-boost assembly during normal operating conditions.
Remedy: Dealers will test the hydro-boost assembly for functional operation of the two-function valve. If the hydro-boost assembly fails the test, dealers will replace the assembly free of charge.
Service brakes, hydraulic
Certain sport utility vehicles, pickup trucks, and passenger vans fail to comply with the requirements of federal motor vehicle safety standard no. 135, ?passenger car brake systems.? Some of these vehicles were produced with an out-of-specification brake hydro-boost housing relief valve bore.
Remedy: Dealers are to replace the hydro-boost relief valve. The recall began on June 18, 2004. Owners should contact Cadillac at 1-866-982-2339; Chevrolet at 1-800-630-2438; GMC at 1-866-996-9463; or Hummer at 1-866-486-6376.
NHTSA defect investigations
Federal safety investigators have looked into 2 possible defects involving the 2004 Hummer H2:
Steering knuckle fracture
During the pe, odi investigated the Hummer h2 for fractures which were occurring at the front steering knuckle lower boss.when the knuckle lower boss fractures, the lower ball joint stud is released and the entire knuckle and wheel/tire assembly separates from the vehicle.odi is upgrading this investigation to gain a full technical understanding of the factors which contributed to these failures.
Hummer h2 steering knuckle failures
Odi upgraded this investigation at the conclusion of pe04-080.the alleged defect involves the failure of the steering knuckle at the lower ball joint boss, resulting in a separation of the lower ball joint from the knuckle.a lower ball joint separation could result in a loss of steering and/or a disabled vehicle.
What 2004 Hummer H2 owners say
Electrical system
Odometer Fraud. The contact purchased a 2004 Hummer H2. The contact discovered a mileage discrepancy after the purchase. The vehicle was a private sale. At the time of purchase, the vehicle mileage was 200,000. It was later discovered that the mileage on the Title was 210,000. Additionally, the contact stated she felt pressured to purchase the vehicle, signed the contract, and was unable to recoup the funds.
Yesterday I turned off the alarm and unlocked the doors via the keypad. I opened the driver door and my wife opened the passenger rear door and the Hummer H2 started. No key in the ignition and the fob does not have a start button. I then got in the car and inserted the key and turned the key to ON then to off and the vehicle would not shut off. Only after cycling through the gears was I able to shut off the vehicle. I have now disconnected the battery to prevent another unwanted start.
Brakes
As I was driving on I 5 in oregon I experienced a complete failure of the electrical system and brake systems. The vehicle was on cruise control and when I disengaged it all of the safety warning light appeared on the dashboard. I pressed on the brakes and they were a complete failure also. At this time the dashboard lights and controls went off and I loss power. I was able to get to the side of the road when I noticed smoke coming from under the hood. I got my daughter out of the vehicle to a safe distance and opened the hood and the main fuse relay panel was fully engulfed in fire. I called 911. In the approx. 5 min. The time the fire truck arrived the truck was consumed and fully gutted out from the fire.
Extremely excessive rust on underbody of my 2004 Hummer H2. Brake lines, calipers, rotors, frame, suspension, etc have holes. My brakes completely failed on the highway and I crashed into a truck and a SUV. Luckily used the emergency brake to eventually stop it. Dealer says entire brake system needs to be replaced and the frame is also in bad shape. I did report the rust problem to GM while under the 3 year warranty but they did nothing. I neither do any cross-country driving nor am near the ocean. I am scared of driving the vehicle.
Windows, wipers & sunroof
Tl* the contact owns a 2004 Hummer H2. The contact stated that the wiper motor for the front windshield became inoperable while the contact was driving in inclement weather, causing the contact to loss control of the vehicle and crash into a guard rail. The dealer and manufacturer were notified of the failure, but denied any assistance with repairs to the vehicle. The vehicle was not repaired. There were no injuries. A police report was not filed. The failure mileage was 70,000 and the current mileage was 80,000.
GM is recalling 13,358 my 2003 Hummer H2 vehicles. Some of these vehicles have a condition in which water can enter the windshield wiper motor module. If a sufficient amount of water enters the module, over time, the front windshield wipers May work intermittently or they May become inoperative. Read more at http://www.cars.com/recalls/Hummer/H2/2003/#85k348wcjdlbcqxu.99
Frequently asked questions
Is the 2004 Hummer H2 a good car?
Based on 59 owner complaints filed with NHTSA, the 2004 H2 rates avoid: 2.7× as many complaints as a typical year of the H2 at the same age. It is one of the H2 years we suggest avoiding. Complaint counts don't account for sales volume or individual maintenance, so have any used car inspected before buying.
What is the most common problem with the 2004 Hummer H2?
The electrical system — 14 complaints, 24% of all complaints for this model year, most often about instrument cluster/panel. Next are the brakes (14) and windows, wipers & sunroof (13).
How many recalls does the 2004 Hummer H2 have?
There are 3 recalls for the 2004 Hummer H2, the most recent from April 22, 2005 (rear/other). Recall repairs are free at any authorized dealer — check whether yours has been done with the VIN recall check.
What are the best and worst years of the Hummer H2?
The best years by complaints, compared at the same age, are 2008, 2007 and 2006. Years to avoid or approach with caution: 2003, 2005 and 2004. See the full Hummer H2 years comparison.
At what mileage do 2004 Hummer H2 problems happen?
The median mileage reported in complaints is about 70,000 miles; 34% of problems with a recorded mileage started before 50,000 miles.
Source: U.S. National Highway Traffic Safety Administration (NHTSA) — owner complaints through October 20, 2026, recalls and defect investigations; fuel economy from the EPA. Complaints are unverified reports and are not proof of a defect. How we rate model years.