Which parts fail
Components named in complaints (battery, alternator, wiring, ignition, instrument cluster, infotainment).
Mileage when the problem started
Owner reports
Selected complaints filed with NHTSA by 2003 Chevrolet Trailblazer EXT owners, lightly cleaned up (personal details are redacted by NHTSA).
One by one things have been going out and not working. First the car would not start all the time with the key, then the A/C stoped working, next was the fuel pump, then the injectors. I checked everything it could be. I was driving with my kids down the highway when my car just died lost power steering so it was hard to get off the road fast. I got it started and was driving and it did it again. I was able to finally get it home when it would not start again. After some research online found out this car has issues with the fuse box itself under the hood. I opened it up just to find the wording that connected the pins was broken in numerous places and had started to burn up in the box.
None of my gages work and a lot of my dash lights are on. I have no idea how much gas I have. My speedometer and RPM gages work but nothing else does. This has been happening on and off for about 3 months but they would always go back on. But now it has been off for a week without going back to normal. Twice last week the radio and the power windows stopped working as well. This happens while driving parked all the time and it doesnt go back to normal. I have seen a lot of complaints about this so I have no clue why there isn't a recall. It is not safe to drive my Trailblazer until these things are fixed. I work at a Chevrolet dealership and they couldn't figure out how to fix this either. GM needs to put out a recall to get this fixed asap.
My key will not come out of the ignition I had to unscrew and remove the bottom of my steering to push the button also all of my instrument gauge do not work including the speedometer and all gauges so I never know my temperature or fuel level, oil pressure they all are not working properly my speedometer only works sometimes. Also my engine is runny rough and I hear a vibration and ticking. My check engine light is and I'm getting code saying theres a leak in the fuel EVAP system. I have searched the internet and everyone has the same problems with their 2003 trailblazers. Why isn't Chevrolet recalling these problems its fustrating they want several hundreds of dollars I cannot afford
When I pulled into driveway, I put the vehicle in park, and turned the key off, and actually pulled the key out of the ignition switch, with the vehicle still running. I backed the car up, without the key in the ignition, where I started smelling wires burning. I called fire department, and they put fire out on the fuse box, with everything melted around it. I have had minor problems with the car, I.e. Wheel bearing and brakes, but, nothing like this. While my 14 year old daughter and I were in the car at the time, we did get out, and no one was hurt.
The drivers seat heater got very hot and then stopped working shortly after. I did an internet search and found that this is very common. I found that one of the wires had overheated and actually burned the foam and covering. There are many complaints and pictures on the internet. I removed my seat and found the exact same problem. I am astounded that nothing is being done to stop the use of these defective heaters. This is most certainly a very serious fire and burn hazard.
Driving at 40mph and the truck went up in flames truck showed no warning even drove it app. 300yards to pull over still ran with flames as high as 6 ft no dummy lights came fire was under the truck while driving was warned by another driving heading towards me truck had 85130 miles on it never had no major problems ever this is a brief summary.
The electronic throttle module to PCM communication error comes up and the vehicle starts the warm up process and then dies in the process of warm up procedures. I guess my question to you is how can I fix this or does a deal need to fix it or is there a recall on this issue?
First oil pressure gauge went and now my speedometer is also gone stuck at 50 MPH. Called Chevy can't get straight answer from them and ask what other vehicles with the same problem with gauge cluster advised can't disclosed any information.
Vehicle shut down while driving on the freeway, ignition locked. Consumer shook the steering column and it started. There was a multiple vehicle collision since the vehicle shut down at 65 MPH.
I have a problem similar to many others. I have recently purchased a 2003 Chevrolet Trailblazer. I have encountered a problem with the speedometer on this vehicle. The speedometer occassionally stops working entirely from time to time and other times, has a mind of it's own and decides to make a random number the zero mark and increase speed from that point. I know that this is a safety issue as there are times that I have no idea how fast I am traveling. I have since taken this matter to general motors in an attempt to give them an opportunity to rectify an unsafe situation. In response, they asked me to take the vehicle into a certified GM dealer for a vehicle diagnostic and repair. I did just that. My vehicle was found to have a problem with the instrument cluster. The dealer was nice enough to inform me that there have been several related problems that GM has issued a recall for... …
Electrical complaints in other Trailblazer EXT years
Frequently asked questions
How common are electrical problems on the 2003 Chevrolet Trailblazer EXT?
NHTSA has 77 complaints about the electrical system of the 2003 Chevrolet Trailblazer EXT, 25% of the model year's 313 complaints. The component named most often is instrument cluster/panel (22 mentions).
Is there a recall for 2003 Chevrolet Trailblazer EXT electrical problems?
No. NHTSA lists no electrical system recall for the 2003 Chevrolet Trailblazer EXT, though it has 3 recalls for other components. If the problem is widespread, a repair may still be covered by an extended warranty or a manufacturer service bulletin — ask a dealer.
At what mileage do 2003 Chevrolet Trailblazer EXT electrical problems start?
Half of the complaints with a recorded mileage happened before about 85,000 miles, and 7% before 25,000 miles.
Is it dangerous?
Owners linked 2 crashes, 4 fires and 0 injuries to electrical system problems on this model year. If you notice symptoms, have the car checked before driving further.
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.