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Transmission and drivetrainPart report

2003 Chevrolet Trailblazer EXT Transmission and drivetrain Problems

Complaints
49about this part
Share
16%of 313 total for the year
Median mileage
60,500miles
Trend
StableComplaints filed in the last 3 full calendar years are within 25% of the 3 years before.

NHTSA recorded 49 complaints about the transmission and drivetrain of the 2003 Chevrolet Trailblazer EXT, 16% of the 313 complaints for this model year. Where a mileage was given, the median is 60,500 miles. 1 of these say a crash was involved and 1 a fire, according to the filers.

Example complaints

Selected from NHTSA records; personal details are removed. They are consumer reports, not findings.

“My 03 ext first transmission went out with just over 65k and then 16mo. Later at 80k went out again. No help from GM. I have owned a 99 blazer and 02 trailblazer with no real issues however this 03 has had numerous from cracked gas tank to catalytic converter going out as well as now having loud engine noise!”

NHTSA complaint #10254697, filed 2009-01, 65,471 miles

“I bought a used 2003 trailblazer. I took it in because it was having issues with the engine light coming on. The engine light no longer comes on but the problem has gotten worse. The transmission slips constantly, I have only had this vehicle for 4 months. I am afraid this is going to happen when I am in the middle of traffic and my children and I will be in serious trouble.”

NHTSA complaint #10217864, filed 2008-02, 42,000 miles

“While driving on a interstate at highway speed. My vehicle had a sudden decrease in forward momentum. The engine RPM's increased dramatically and the vehicle had unpredictable surges and loss of ability to maintain speed. After driving down the berm to the interstate exit, I noted a burning smell. The smell was that of transmission fluid that had leaked out from a corroded transmission cooling line.”

NHTSA complaint #10284639, filed 2009-09, 71,590 miles

“My Chevrolet Trailblazer Ext, that I purchased 4 1/2 years ago and it has 44,000 miles on it, has a transmission problem. The Chevrolet dealership tells me that it is a 2000 fix. I am angry and disappointed that a vehicle with relatively few miles on it is having such a major problem.”

NHTSA complaint #10222042, filed 2008-03, 44,000 miles

“Driving on vacation towing camper. Tried to accelerate and nothing. Got to gas station. No trans fluid. Got it to dealership . They said trans blown due to water in trans. Dipstick rusted inhalf. Leak with hose caused problem. Got fixed GM only paid 1/2 because we fought. Had extended warranty they said manufacturer defect. Found service bulletin on internet. Still fighting to get our money back .only 51,000 miles.”

NHTSA complaint #10242087, filed 2008-09, 51,000 miles

Related service bulletins

Transmission and drivetrain: other model years

YearComplaintsShare of year
200663%
2004177%
20034916%
20022020%

Other parts of the 2003 Chevrolet Trailblazer EXT

Fuel system
89 complaintsElectrical system
77 complaintsVisibility (wipers, defrost, mirrors)
26 complaintsExterior lighting
23 complaintsBody and structure
20 complaintsEngine cooling
16 complaintsBrakes
13 complaintsLatches, locks and linkages
13 complaintsSuspension
12 complaintsOther or unknown
7 complaintsVehicle speed control
7 complaintsSteering
6 complaints

← All problems reported for the 2003 Chevrolet Trailblazer EXT

About this data. Data from NHTSA (ODI) complaints, recalls, TSBs and investigations, updated Oct 31, 2026. Complaints are unverified consumer reports and may be duplicated or inaccurate.

To check a specific vehicle for open recalls, use its VIN at nhtsa.gov/recalls. Methodology