2003 Chevrolet Trailblazer EXT Problems

What owners report

Owners of this model year most often describe fuel leaks and strong fuel or vapor smells traced to the fuel tank filler neck or the sending unit on top of the tank, and a second large group reports instrument cluster problems, especially a speedometer that reads high or stops working. Transmission failures and broken door latches also appear repeatedly in the sample, and most reports fall between roughly 50,000 and 100,000 miles.

1. 1
   Fuel system

   Fuel smell and leaks from tank filler neck or sending unit

   • 83 complaints (27%)
   • median 75,000 mi at 5.3 yrs old (68 state mileage)
   • owner-quoted repair $900 (median of 23 quotes)
   • filed 2004–2019

   Complaints describe a strong gasoline odor around and inside the vehicle, sometimes with visible fuel pooling or dripping under the tank, and a check engine light in some cases. Dealers and mechanics diagnosed a cracked filler neck or a corroded sending unit and lines on top of the tank, and in many cases replaced the tank, pump module and lines. Several owners mention a special coverage or warranty extension on the fuel tank inlet check valve and say they were told the vehicle was outside the time or mileage limit. Mostly reported between about 50,000 and 130,000 miles, with several cases appearing after the vehicle sat or shortly after fueling.

   4 related service bulletins

   What to check: Ask whether the fuel tank inlet check valve special coverage was ever applied, and inspect the filler neck and the top of the tank for cracks or corrosion. A fuel smell at the rear or after filling is worth investigating before purchase.

   2 excerpts from owner complaints in NHTSA records

   “I have intermittent smell of fuel coming from vehicle; consistently declining mpg; ses light coming on; taken it to the dealership after having received a letter stating that there was a fuel tank or pump issue; they diagnosed that the filler neck was cracked a nd leaking but stated that it wasn't part of the repairs from the letter and said it would cost a $1000 to replace my fuel tnk and then they would replace the fuel pump module for free.”

   NHTSA complaint #10263953, filed 2009-04, 99,000 miles

   “I smelled a strong odor of gasoline, and had fuel leaking from the gas tank. I was afraid to keep driving it like that, I took it to get repaired. The service technician had to replace the sending unit module, part # mu1377. He said it was corroded.”

   NHTSA complaint #10187405, filed 2007-04, 73,037 miles
2. 2
   Electrical system

   Speedometer and instrument cluster gauge failures

   • 59 complaints (19%)
   • median 85,000 mi at 6.8 yrs old (53 state mileage)
   • 1 mention a crash, fire or injury
   • owner-quoted repair $600 (median of 7 quotes)
   • filed 2005–2018

   Owners describe gauges that quit or read incorrectly: a speedometer stuck at 50 mph or pegged high while parked, and temperature, oil pressure, fuel and volt gauges that stop working one after another. Some report the cluster resetting itself, dash lights staying on, and other electrical items such as the radio or power windows dropping out at the same time. Dealers typically quoted several hundred dollars to replace or repair the cluster. Reported from roughly 40,000 to 130,000 miles, and several owners note the speedometer misbehaving more in cold or snowy weather.

   3 related service bulletins

   What to check: With the engine running, confirm every gauge moves and returns to rest, and check the speedometer against a known speed. Ask whether the cluster has been repaired or replaced and whether it is covered by any warranty.

   2 excerpts from owner complaints in NHTSA records

   “I noticed when the weather got colder/snow in december, my speedometer was reading around 60 mpg high speed when I was going about 20 MPH. After turning my truck on and off a couple of times, it would reset to 0 MPH. Another heavy snow day came and it happened again, and after I was exiting my car yesterday, the needle pointed south and when I started the truck it went backward to 120 MPH. …”

   NHTSA complaint #10252659, filed 2008-12, 62,228 miles

   “For the past several months, the speedometer has been acting up. It is now buried past the top registered speed. It will vary from time to time, but is, for the most part, non-working. It will show that I am at a high rate of speed even when the vehicle is sitting idle or in park. This is an ongoing problem and from what I can see, I am not alone with this issue. This is a big safety concern and I feel that GM needs to address the issue.”

   NHTSA complaint #10248368, filed 2008-11, 121,000 miles
3. 3
   Transmission and drivetrain

   Transmission failure and loss of drive

   • 37 complaints (12%)
   • median 65,828 mi at 5.6 yrs old (31 state mileage)
   • 1 mention a crash, fire or injury
   • owner-quoted repair $1,200 (median of 7 quotes)
   • filed 2004–2015

   Complaints describe the vehicle suddenly losing forward gears or refusing to accelerate, sometimes with the engine revving and no drive, in a few cases while driving at highway speed. Dealers diagnosed internal failures such as stator support bushings and recommended overhaul or replacement. Some owners also report corroded transmission fluid cooler lines leaking fluid, and one notes the dealer described a delayed throttle response on rapid acceleration as normal. Mostly reported between about 35,000 and 130,000 miles, with no clear pattern of towing or heavy use.

   3 related service bulletins

   What to check: Test drive from a cold start through several upshifts and check that engagement into drive and reverse is firm. Look at the transmission fluid level and color and inspect the cooler lines for rust or seepage.

   2 excerpts from owner complaints in NHTSA records

   “The incident occurred while driving home after dropping my son off at work on I-95. I was traveling between 65 and 70 MPH and passing a semi when my vehicle suddenly and with no prior warning shifted into second gear. Luckily I was able to maintain control of my car and able to drive it the rest of the way home. On monday I drove my vehicle as instructed to the mj sullivans, the dealership in which I bought the trailblazer, for service. …”

   NHTSA complaint #10144757, filed 2005-12, 70,650 miles

   “Traveling up a draw bridge at 50 miles per hour the transmission quit completely, the engine would rev up but no drive from the transmission. Fortunately, no one rear ended the vehicle as we slowed down and barely made it over the top of the bridge and then coasted down enough to get off of the bridge. The vehicle was towed to a dealer and they determined that the transmission must be completely replaced at my cost. The vehicle has 64,000 miles, too few for a transmission failure.”

   NHTSA complaint #10154458, filed 2006-04, 64,517 miles
4. 4
   Body and structure

   Door latches that release or fail to latch

   • 29 complaints (9%)
   • median 52,000 mi at 4.5 yrs old (25 state mileage)
   • 4 mention a crash, fire or injury
   • owner-quoted repair $750 (median of 6 quotes)
   • filed 2004–2014

   Owners report doors that appear closed but open while driving or turning a corner, and latches that will not release. Some describe repeated replacements of the latch mechanisms, and at least one notes the rear door opened again after a recall repair. Complaints also mention the rear hatch glass and the top trim section above the tailgate separating or the glass shattering. Reported from about 40,000 to 110,000 miles, and recall-related rear latch work was described in a vehicle with roughly 52,000 miles at the time.

   Recall 05V494000

   What to check: Open and close each door and the rear hatch several times and confirm they latch firmly and stay shut with the vehicle in motion. Ask whether the rear latch recall work was completed and whether any latches have been replaced since.

   2 excerpts from owner complaints in NHTSA records

   “Three of the four door latching mechanisms had to be replaced in this truck. The doors would look like they closed but they would open as you turned a corner. This occurred twice when I had my kids in the truck, first on the passenger left side then a few months later the passenger right side. I am glad GM didn't screw up the seal belts too. This is dangerous.”

   NHTSA complaint #10257230, filed 2009-02, 70,000 miles

   “The rear window in the gate on my 2003 trailblazer has become disconnected on one side at the hinge. It appears to be a defect with the way it is adhered (via some sort of glue) as there is no damage to the area itself. As my vehicle is an ext model, it has a section across the very top that is also simply glued to the body which holds the centrally mounted brake light. …”

   NHTSA complaint #10229377, filed 2008-05, 112,000 miles
5. 5
   Exterior lighting

   Headlamps, brake lamps and tail lamp housings

   • 24 complaints (8%)
   • median 71,700 mi at 5.9 yrs old (17 state mileage)
   • 2 mention a crash, fire or injury
   • filed 2004–2014

   Complaints describe headlamps going out repeatedly with melted or burnt connectors, and brake or tail lamps that stop working even after the bulb and control board are replaced. Some owners report the high-mount rear stop lamp housing coming loose or detaching from the tailgate. Bulb socket looseness from vibration and heat is described in a related recall. Reported across a wide mileage range, roughly 50,000 to 120,000 miles.

   Recall 04V5270002 related service bulletins

   What to check: Check that all exterior lamps work and look at the headlamp connectors and bulb sockets for browning or melting. Ask whether the brake lamp recall was performed and whether the rear lamp housing is still attached at the tailgate.

   2 excerpts from owner complaints in NHTSA records

   “Purchased a 2003 chevy trailblazer-ext lt in dec 2002 from the dealer, team Chevrolet in pasadena. Since purchasing the vehicle, there's been several recalls, one in particular that keeps recurring are the brake lights keep burning, the dealer changed both units but it keeps burning out. I got tired of taking it to the dealer, so I purchased new bulbs and looked into replacing them myself. …”

   NHTSA complaint #10315703, filed 2010-03, 89,500 miles

   “High mount rear stop tail lamp assembly is loose. Opened the tailgate on 5/11/09 heard metal crunching. Ever since my back glass vibrates violently when going down the highway, increasing the possibility of it blowing out. On 5/17/09 after further investigation noticed that the top assembly has broken away from the truck on both sides (still being held on by the center) should this come off it puts me and drivers behind me at risk of an accident. This problem puts my children at risk of glass shattering on them or being involved in an accident. …”

   NHTSA complaint #10268989, filed 2009-05, 52,000 miles

Buying note. A pre-purchase inspection should focus on fuel system condition, gauge cluster function and transmission behavior, since those are the areas owners most often describe. Ask for records of any fuel tank or latch recall and special coverage work, and budget for aging electrical and fluid-line repairs on a vehicle of this age.

Summary written with AI from a sample of 60 NHTSA complaints for this model year (picked at random, with complaints that state a mileage and recent ones taken first), then checked automatically against the source records. Where a problem shows a complaint count, every complaint for this model year was matched with fixed keyword rules (written with AI and tested against the sample), and the mileage, age and repair figures are calculated from those complaints; owners' figures are as stated, not verified. Other counts refer to the sample. The excerpts come from NHTSA's public complaint records and are unverified; capitalisation is normalised, NHTSA staff notes are removed, and shortened text ends with “…”. Something wrong? Request a correction.