Most common 2003 Chevrolet Trailblazer EXT 370 problems
Share of the 14 complaints; one complaint can involve more than one system. "~" is the median mileage when the problem started.
Chevrolet Trailblazer EXT 370 complaints by model year
Best Trailblazer EXT 370 years: 2002, 2003. Years to avoid: 2005. Compare all years →
NHTSA defect investigations
Federal safety investigators have looked into 3 possible defects involving the 2003 Chevrolet Trailblazer EXT 370:
Fuel tank leak
In June 2007, GM will expand its special policy to address fuel tank inlet check valve (icv) fractures on certain model year (my) trailblazer ext and GMC envoy xl vehicles.the expanded policy covers my 2002-2004 trailblazer ext, GMC envoy xl, and GMC envoy xuv vehicles and will extend for a period of 10 years or 150,000 miles (whichever comes first).GM will provide free repair of the fuel tank.
Fuel pump module leaks gasoline
Odi has received reports that the fuel pump module leaks fuel and or vapor underneath the vehicle.GM states, the failure mechanism is corrosion of the fuel pump module flange which May lead to a fuel leak.corrosion of the fuel pump module flange is the result of the vehicle operating in a corrosive environment.odi has upgraded this pe to engineering analysis (ea07-009) to further assess this issue.
Fuel pump module leaks gasoline
During the course of this ea investigation, odi observed that the majority of the complaints (88%) and warranty claims (94%) were reported for vehicles that are registered for use in the salt belt region of the us.this area includes 20 states in the northeast, mid atlantic and the midwest regions and the district of columbia.consumers in the salt belt region reported to odi that they could smell fuel vapors in their…
What 2003 Chevrolet Trailblazer EXT 370 owners say
Electrical system
Tl* the contact owns a 2003 Chevrolet Trailblazer EXT 370. The contact stated that the turn signals do not function properly and the hazard lights illuminated instead of the turn signals. The contact was able to press the button for the hazard lights when needed, but not the turn signals. The vehicle was not diagnosed. The failure continued and caused the front headlight assembly and the rear headlight assembly to short and dim with no warning. The vehicle was not repaired. The manufacturer was notified of the failure. The approximate failure mileage was 150,000.
2003 Chevrolet Trailblazer 370 rear passenger side door electrical window control switch would not completely close window . Smelled like electrical wire burning. Had vehicle stop at time and had assistance in removing door interior panel and found electrical window switch completely melted and wire connection burned . Personal vehicle used on vacation, stopped just off highway at time .
Fuel & propulsion system
There is a known problem with the gas tanks on these vehicles. The vapors cause the check engine light to illuminate. In nys this car will not pass the yearly inspection. Chevrolet has an extended coverage bulletin out but it only is for vehicles that have les than 150,000 miles on it or are not older than 15 years old. Whichever come first. Prior to this, their extended coverage was for 150,000 miles or 12 years. I was excluded from the first time due to age of the vehicle when I purchased it and am now excluded from the second extended coverage due to the mileage. It is absolutely ridiculous that this is not an official recall and that Chevy has loopholed numerous owners out of the coverage by not increasing the mileage requirement. The national average to drive a car according to the NHTSA is between 15,000 and 16,000 per year. …
Tl* the contact owns a 2003 Chevrolet Trailblazer EXT 370. The contact stated that while driving at various speeds, the vehicle surged forward and the rpms fluctuated without warning. In addition, the contact stated that an abnormal fuel odor emitted from the vehicle as the check fuel warning light illuminated. The vehicle was taken to the dealer where it was diagnosed that the fuel tank vacuum and fuel tank needed to be replaced. The vehicle was not repaired. The manufacturer was not notified of the failure. The failure mileage was approximately 150,000.
Frequently asked questions
Is the 2003 Chevrolet Trailblazer EXT 370 a good car?
Based on 14 owner complaints filed with NHTSA, the 2003 Trailblazer EXT 370 rates average: 58% fewer complaints than a typical year of the Trailblazer EXT 370 at the same age. It is one of the best Trailblazer EXT 370 years by this measure. 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 2003 Chevrolet Trailblazer EXT 370?
The electrical system — 6 complaints, 43% of all complaints for this model year. Next are the fuel & propulsion system (3) and engine & cooling (2).
How many recalls does the 2003 Chevrolet Trailblazer EXT 370 have?
NHTSA lists no recalls for the 2003 Chevrolet Trailblazer EXT 370. You can still confirm with your VIN using our VIN recall check.
What are the best and worst years of the Chevrolet Trailblazer EXT 370?
The best years by complaints, compared at the same age, are 2002 and 2003. Years to avoid or approach with caution: 2005. See the full Chevrolet Trailblazer EXT 370 years comparison.
At what mileage do 2003 Chevrolet Trailblazer EXT 370 problems happen?
The median mileage reported in complaints is about 140,000 miles; 8% 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.