IllustrationDT*: THE CONTACT STATED THE HEADLIGHTS DIM WITHOUT WARNING. THE PROBLEM OCCURS INTERMITTENTLY AND HAS INCREASED OVER TIME. UPON INSPECTION THE DEALERSHIP DETERMINED THE PROBLEM IS RELATED TO THE DEFROSTER IN THE AC COMPRESSOR. THE DIMMING OF THE HEADLIGHTS IS NORMAL FOR THE VEHICLE. UPDATED 02/24/06
2004 Chevrolet Trailblazer
Owner reports · Recalls · Investigations
More warning signs than most Trailblazer years
Owner complaints for the 2004 Chevrolet Trailblazer are substantially higher than the model-year median of 87.5.
About this comparison →How this year compares
Owner complaints by model year
Compare all Trailblazer years →Counts vary with age, sales and reporting. They are not failure rates.
What owners reported most
All reported categories
Tap a category to read its complaints. One report may name several components.
When problems were reported
Mileage at the reported incident
880–25K
16325–50K
27450–75K
17675–100K
137100–150K
61150K+
899 reports with mileage · 182 unknown
NHTSA’s mileage field refers to the reported incident, not necessarily the filing date. This shows report counts, not the likelihood of a failure.
What to inspect
Issues worth paying extra attention to based on owner reports.
- Electrical System. Review the 627 owner reports in this category and discuss these concerns during a pre-purchase inspection. Read reports →
- Exterior Lighting. Review the 101 owner reports in this category and discuss these concerns during a pre-purchase inspection. Read reports →
- Fuel System, Gasoline. Review the 93 owner reports in this category and discuss these concerns during a pre-purchase inspection. Read reports →
NHTSA owner reports · September 18, 2026 snapshot.
56 crash reports31 fire reports47 injury reports
What owners actually said
1,081 reportsI BOUGHT VEHICLE IN OCTOBER 2003. IT IS A 2004 CHEVROLET TRAILBLAZER. IN THE MONTHS FOLLOWING I BEGAN HAVING ELECTRICAL PROBLEMS . CHECK ENGINE LIGHT WOULD FLASH ON AND THEN WENT OFF AGAIN. THE FIRST TIME IT HAPPENED CAR STALLED AS WELL. I WOULD BRING IT IN TO THE DEALERSHIP AND THEY WOULD SAY THAT THEY COULD NOT DUPLICAT…
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I BOUGHT VEHICLE IN OCTOBER 2003. IT IS A 2004 CHEVROLET TRAILBLAZER. IN THE MONTHS FOLLOWING I BEGAN HAVING ELECTRICAL PROBLEMS . CHECK ENGINE LIGHT WOULD FLASH ON AND THEN WENT OFF AGAIN. THE FIRST TIME IT HAPPENED CAR STALLED AS WELL. I WOULD BRING IT IN TO THE DEALERSHIP AND THEY WOULD SAY THAT THEY COULD NOT DUPLICATE THE PROBLEM, AND THEY HOOKED UP TO THE COMPUTER AND DIDN'T FIND ANY PROBLEMS. I ALSO HAD MY HEADLIGHTS FLICKER WHEN ACCELERATING AND DECELERATING. I HAVE HAD NUMEROUS PROBLEMS WITH MY BLINKERS. I HAVE HAD THE TAIL LIGHT ASSEMBLIES REPLACED TWICE. I RECENTLY TOOK IT AGAIN BECAUSE MY LEFT BLINKER WOULD FLASH MUCH FASTER WHEN I TOUCHED THE BRAKE. ALSO, IF I JUST TOUCHED THE BRAKE THE RIGHT BLINKER LIGHT ON MY CONSOLE WOULD ILLUMINATE. ALSO, IT LOOKED AS IF I HAD MY LIGHTS ON FOR REVERSING WHILE I WAS DRIVING, WHICH WAS EXTREMELY UNSAFE AS OTHER DRIVERS THOUGHT I WAS REVERSING WHEN I WAS GOING FORWARD. I HAVE HAD 4WD LIGHT COME ON AND THEN TURN OFF AGAIN LATER. I HAVE HAD MY MAIN COMPUTER REPLACED TWICE AND MY FLASHER COMPUTER REPLACED ONCE. I HAD TO HAVE MY KEYS REPROGRAMMED TWICE AND THEY FINALLY FOUND OUT TODAY I HAD FAULTY ELECTRICAL WIRING WHICH WAS SUPPOSEDLY CAUSING THE TROUBLE WITH THE BRAKES AND FLASHERS. I HAVE BROUGHT IT IN FOR THIS PROBLEM 3 TIMES IN THE LAST COUPLE WEEKS. I ALSO HAVE A PROBLEM WITH THE GAS TANK OVERFLOWING EVERYTHING I FILL UP NO MATTER WHAT I DO AND I AM NOT TRYING TO "TOP OFF". ALSO, I HAVE HAD SEVERAL PROBLEMS WITH MY SEAT BELTS AND HAVE THEM REPLACED AS WELL. THEY WOULD LOCK AND I WOULD BE UNABLE TO GET IT ONE TO DRIVE THE CAR SAFELY. I HAD TO DRIVE MY CAR TO THE DEALERSHIP WITH NO SEAT BELT. OVERALL, THESE PROBLEMS AMOUNT TO A POORLY MADE VERY EXPENSIVE CAR THAT LEAVES ME FEELING UNSAFE IN MY CAR. PLEASE MAKE CHEVROLET LISTEN TO ITS CONSUMERS AND PAY RESTITUTION. WE WERE ALL LIED TO BY THE CAR MANUFACTURER, WHO HAD TO HAVE KNOWN IT WAS PRODUCING AN INFERIOR PRODUCT.*AK
I TURNED ON THE REAR WINDOW DEFROSTER ON MY 2004 CHEVROLET TRAILBLAZER. AFTER APPROXIMATELY 2 MINUTES THE REAR LIFTGATE GLASS EXPLODED. THE TRUCK IS AT DICK MORRIS CHEVROLET IN COMMERCE TOWNSHIP MICHIGAN NOW. *NM
MY 2004 CHEVROLET TRAILBLAZER INTERMITTENTLY STALLS OUT IN TRAFFIC. IT HAS BEEN TO THE DEALERSHIP 5 TIMES FOR REPAIR, WITH NO RESULTS. THE DEALER HAS ACTUALLY BEEN ABLE TO REPRODUCE IT, AND HAS REPLACED ITEMS, BUT GM IS UNABLE TO ISOLATE THE PROBLEM. *JB
I OWN A 2004 CHEVROLET TRAILBLAZER LT. ON DECEMBER 5, 2005, MY WIFE BACKED THE VEHICLE OUT OF OUR BASEMENT. SHE NOTICED SMOKE COMING FROM THE DASHBOARD. IMMEDIATELY,SHE SAW FLAMES. THE VEHICLE BURNED COMPLETELY, ALSO BURNING THE END OF MY HOME. I CONTACTED G.M. ABOUT THIS PROBLEM AND WAS TOLD I WAS WAY DOWN THE LIST OF PROBLEM…
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I OWN A 2004 CHEVROLET TRAILBLAZER LT. ON DECEMBER 5, 2005, MY WIFE BACKED THE VEHICLE OUT OF OUR BASEMENT. SHE NOTICED SMOKE COMING FROM THE DASHBOARD. IMMEDIATELY,SHE SAW FLAMES. THE VEHICLE BURNED COMPLETELY, ALSO BURNING THE END OF MY HOME. I CONTACTED G.M. ABOUT THIS PROBLEM AND WAS TOLD I WAS WAY DOWN THE LIST OF PROBLEMS. MY CONCERN IS THAT THIS COULD BE A SERIOUS PROBLEM THAT COULD RESULT IN DEATH THE NEXT TIME THIS HAPPENS. I SINCERELY HOPE THIS IS NOT THE CASE. I WOULD HOPE THAT G.M. WOULD LOOK INTO THIS MATTER BEFORE THIS HAPPENS AGAIN. CONSIDERING THIS VEHICLE WAS PURCHASED NEW AND HAD ONLY 27,000 MILES ON THE VEHICLE. *NM *TR
ON 5 SEPARATE OCCASIONS, THE ENGINE ON MY 2004 TRAILBLAZER HAS STALLED WHILE IN TRAFFIC. 1 TIME, THE ENGINE STALLED WHEN I APPLIED THE BRAKES; EVERY OTHER TIME, THE ENGINE STALLS WHILE AT IDLE. I HAVE TAKEN IT INTO THE DEALERSHIP REPEATEDLY, AND THEY HAVE BEEN UNABLE TO DUPLICATE BUT NOT FIX THE PROBLEM. THEY HAVE REPLACED TH…
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ON 5 SEPARATE OCCASIONS, THE ENGINE ON MY 2004 TRAILBLAZER HAS STALLED WHILE IN TRAFFIC. 1 TIME, THE ENGINE STALLED WHEN I APPLIED THE BRAKES; EVERY OTHER TIME, THE ENGINE STALLS WHILE AT IDLE. I HAVE TAKEN IT INTO THE DEALERSHIP REPEATEDLY, AND THEY HAVE BEEN UNABLE TO DUPLICATE BUT NOT FIX THE PROBLEM. THEY HAVE REPLACED THE MANIFOLD PRESSURE VALVE AND CLEANED THE THROTTLE PLATES, BUT THE PROBLEM STILL PERSISTS. *JB
I BOUGHT THIS VEHICLE BRAND NEW AND SINCE PURCHASE IT IS IN AND OUT OF THE SHOW WITH NUMEROUS ELECTRICAL AND GAS PROBLEMS. EVERYTIME YOU PUT GAS IN THE VEHICLE IT SPILLS OUT FROM THE UNDERSIDE. THE DEALERSHIP HAS REPLACE PARTS PERTAINING TO THE FUEL SYSTEM AND IT HAS NOT SOLVED THE PROBLEM. MY RADIO HAS BEEN REPLACED AND STIL…
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I BOUGHT THIS VEHICLE BRAND NEW AND SINCE PURCHASE IT IS IN AND OUT OF THE SHOW WITH NUMEROUS ELECTRICAL AND GAS PROBLEMS. EVERYTIME YOU PUT GAS IN THE VEHICLE IT SPILLS OUT FROM THE UNDERSIDE. THE DEALERSHIP HAS REPLACE PARTS PERTAINING TO THE FUEL SYSTEM AND IT HAS NOT SOLVED THE PROBLEM. MY RADIO HAS BEEN REPLACED AND STILL DOES NOT WORK PROPERLY. MY HEADLIGHTS DIM UP AND DOWN, THE AIR BLOWS LOW AND HIGH THE INTERIOR LIGHTS FLASH OFF AND ON THE ENGINE RUNS ROUGH AND ALL THESE SYMPTOMS HAPPEN SPORADICALLY. IT HAS BEEN IN THE DEALERSHIP NUMEROUS TIMES AND EVERYTIME I TAKE IT THEY STATE THEY CANNOT DUPLICATE THE PROBLEM. THIS VEHICLE I FEEL IS A SAFETY ISSUE AND I DO NOT FEEL COMFORTABLE PUTTING MY FAMILY IN IT. I AM CURRENTLY FILING A LEMON LAW COMPLAINT WITH THE BETTER BUSINESS BUREAU. *JB
LAST WEEK IT WAS COLD & SNOWING. I WAS COMING TO A STOP SIGN AT A VERY LOW SPEED. I ATTEMPTED TO BRAKE, THE VEHICLE DID NOT. I PROCEEDED THROUGH THE STOP SIGN AND STRUCK ANOTHER VEHICLE. AGAIN TODAY I WAS APPROACHING A STOP SIGN WHEN I ATTEMPTED TO BRAKE, THE VEHICLE DID NOT STOP. TODAY THERE WAS LUCKILY NO ON COMING TRAFFI…
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LAST WEEK IT WAS COLD & SNOWING. I WAS COMING TO A STOP SIGN AT A VERY LOW SPEED. I ATTEMPTED TO BRAKE, THE VEHICLE DID NOT. I PROCEEDED THROUGH THE STOP SIGN AND STRUCK ANOTHER VEHICLE. AGAIN TODAY I WAS APPROACHING A STOP SIGN WHEN I ATTEMPTED TO BRAKE, THE VEHICLE DID NOT STOP. TODAY THERE WAS LUCKILY NO ON COMING TRAFFIC. I WILL BE TAKING MY VEHICLE IN FOR INSPECTION. *NM
DT: THE CONTACT STATED WHEN SHE OPENED THE HATCHBACK THE WINDOW GLASS SHATTERED.*AK UPDATED 2/7/2006 - *NM
MY FIRST COMPLAINT CAME AFTER THE WARRANTY EXPIRED AND MY WATER PUMP SUDDENLY WENT OUT. I GOT THAT FIXED AND THEN I STARTED HEARING A NOISE ON THE PASSENGER SIDE NEAR THE RIGHT FRONT TIRE. WE STILL HAVE NOT BEEN ABLE TO FIGURE OUT WHAT THIS IS. NOW I AM HAVING TROUBLE WITH THE RPM AND SPEEDOMETER JUST JUMPING AND GOING OUT OF…
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MY FIRST COMPLAINT CAME AFTER THE WARRANTY EXPIRED AND MY WATER PUMP SUDDENLY WENT OUT. I GOT THAT FIXED AND THEN I STARTED HEARING A NOISE ON THE PASSENGER SIDE NEAR THE RIGHT FRONT TIRE. WE STILL HAVE NOT BEEN ABLE TO FIGURE OUT WHAT THIS IS. NOW I AM HAVING TROUBLE WITH THE RPM AND SPEEDOMETER JUST JUMPING AND GOING OUT OF WHACK. I GOT IT FIXED IN LUMBERTON NC AT THE CHEVY DEALER AND BEFORE I GOT HOME THE SAME THING WAS HAPPENING AGAIN. I AM SCHEDULING AN APPOINTMENT TO TAKE IT BACK IN AGAIN AND THIS TIME THEY SAY THEY WILL HAVE TO REPLACE THE GAUGE WHICH WILL COST APPROXIMATELY $350. THIS IS RIDICULOUS CONSIDERING I HAVE ONLY HAD THE VEHICLE A YEAR AND SOME MONTHS. I TALKED TO A FRIEND OF MINE WHICH HAD A GMC YUKON AND SHE HAD THE SAME PROBLEMS WITH THE RPMS AND SPEEDOMETER. SHE FINALLY GOT RID OF HER AND SHE SAID SHE HAD THE SAME NOISE PROBLEM. I THINK THAT GMC SHOULD BE MADE TO CORRECT ALL THESE PROBLEMS AND NOT THE CONSUMER TAKE RESPONSIBILITY FOR THEIR IMPERFECTIONS. *NM
Official recalls
205V198000 · Exterior Lighting:turn Signal
May 5, 2005
ON CERTAIN TRUCKS AND SPORT UTILITY VEHICLES, THE DRIVER WISHING TO SIGNAL A TURN BY MOVING THE DIRECTIONAL SIGNAL LEVER, (UP OR DOWN) MAY CAUSE THE FRONT MARKER/TURN LIGHTS AND REAR TURN LIGHTS TO FLASH IN A MANNER SIMILAR TO HAZARD WARNING, RATHER THAN FLASHING ON THE DESIRED SIDE ONLY.
Consequence & remedy
Consequence: THE DRIVER MAY NOT BE ABLE TO CLEARLY SIGNAL THEIR INTENTIONS TO TURN, CHANGE TRAVEL LANES, OR POTENTIALLY WARN OTHERS OF AN IMPAIRED VEHICLE OPERATING CONDITION INCREASING THE RISK OF A CRASH.
Remedy: DEALERS WILL REPLACE THE SUSPECT FLASHER MODULES WITH A NEW FLASHER MODULE DESIGNED WITH SEALED RELAYS AND MORE DURABLE CONTACT MATERIAL INSIDE OF THE RELAYS FREE OF CHARGE. THE RECALL BEGAN ON AUGUST 4, 2005. ISUZU BEGAN MAILING OWNER LETTERS ON AUGUST 4, 2005. OWNERS MAY CONTACT CHEVROLET AT 1-800-630-2438, GMC AT 1-866-996-9463, ISUZU AT 1-800-255-6727, BUICK AT 1-866-608-8080, AND OLDSMOBILE AT 1-800-630-6537.
04V527000 · Exterior Lighting:brake Lights
Nov 1, 2004
ON CERTAIN SPORT UTILITY VEHICLES, VIBRATION AND HEAT MAY CAUSE THE TAIL LAMP/STOP LAMP BULB TO LOOSEN IN ITS SOCKET. IF THIS OCCURS, THE BULB MAY FLICKER AND EVENTUALLY BECOME INOPERATIVE.
Consequence & remedy
Consequence: AN INOPERATIVE BRAKE LAMP WILL NOT CONVEY THE DRIVER'S INTENTION OF STOPPING TO DRIVERS IN FOLLOWING VEHICLES, AND AN INOPERATIVE REAR TURN SIGNAL LAMP WILL NOT CONVEY THE DRIVER'S INTENTION TO TURN TO DRIVERS IN FOLLOWING VEHICLES. BOTH OF THESE FAILURES CAN INCREASE THE RISK OF A CRASH.
Remedy: DEALERS WILL INSPECT THE TAIL LAMP/STOP LAMP ASSEMBLIES, AND IF NECESSARY, REPLACE THEM. THE RECALL BEGAN ON NOVEMBER 22, 2004. OWNERS SHOULD CONTACT CHEVROLET AT 1-800-630-2438, OLDSMOBILE AT 1-800-630-6537, BUICK AT 1-866-608-8080, OR GMC AT 1-866-996-9463.
Model-level recall history does not show whether a particular VIN is affected or has received a repair. Check a VIN with NHTSA ↗
NHTSA investigations
4RQ17002 · Loss Of Headlights
Opened Apr 24, 2017 · Closed Mar 29, 2021
Status: closed (inferred from source dates) · Exterior Lighting:headlights
The subject vehicles are model year (MY) 2002-2009 Chevrolet Trailblazer, GMC Envoy, 2004-2007 Buick Rainier, 2003-2008 Isuzu Ascender, 2005-2009 Saab 9-7X, 2002-2004 Oldsmobile Bravada, 2003-2006 Chevrolet SSR, 2005-2009 Buick Lacrosse, and 2006-2008 Pontiac Grand Prix. This scope includes the Trailblazer/Envoy variants: 2002-2006 Envoy XL/Trailblazer EXT and 2004-2005 Envoy XUV. The original scope of this investigation was expanded to include all vehicles equipped with the subject Headlight Driver Module (HDM). The focus of the investigation was to determine whether actions performed by General Motors adequately addressed any unreasonable risk to motor vehicle safety in the subject vehicles concerning the headlights and the HDM that controls them.Under normal electrical load and environmental conditions, the HDM can overheat inside the Underhood Electrical Center (UEC). This can cause the module to fail and result in a simultaneous loss of both low beam headlights and both daytime running lights (DRLs), often with no warning or prior detectability to the driver. This failure can be intermittent or permanent. No other exterior lights are affected. High beams, turn signals, brake lights, and reverse lights are still operational.General Motors addressed this issue with 2 recalls (14V755 & 15V519) and a special coverage program (N172091910). In view of the recalls and special coverage program implemented by GM and the vehicle high beams continuing to operate, ODI has tentatively concluded that the actions taken by GM mitigate any unreasonable risk to safety posed by HDM failure in the subject vehicles.Accordingly, the investigation is closed. The closing of this investigation does not constitute a finding by NHTSA that a safety-related defect does not exist. The agency reserves the right to take additional action if warranted by new circumstances.The ODI reports cited above are available for review online at NHTSA.gov under the identification numbers in the attached document.
EA07009 · Fuel Pump Module Leaks Gasoline
Opened Jul 10, 2007 · Closed Aug 28, 2008
Status: closed (inferred from source dates) · Fuel System, Gasoline:delivery:fuel Pump
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 VEHICLES WHILE DRIVING.UPON FURTHER EXAMINATION OF THEIR VEHICLES, THEY DISCOVERED THAT FUEL VAPORS WERE COMING OUT OF THE TOP OF THE FUEL TANK. THIS CONDITION IS CAUSED BY CORROSION OF THE RETURN AND SENDER LINES OF THE FUEL PUMP MODULE.WATER AND ROAD SALT COLLECT ON TOP OF THE FUEL PUMP LEADING TO SMALL PINHOLES APPEARING ON THE FUEL LINES.FUEL MAY LEAK AND COLLECT ON TOP OF THE MODULE AND/OR SPILL ONTO THE GROUND.THE DATA EVALUATED UNDER THIS INVESTIGATION REFLECT A RELATIVELY LOW FREQUENCY OF OCCURRENCE THAT LARGELY ARISES IN SALT BELT STATES.GM HAS EXTENDED THE WARRANTY ON THE SUBJECT COMPONENT TO TEN YEARS OR 120,000 MILES.FURTHER USE OF AGENCY RESOURCES DOES NOT APPEAR TO BE WARRANTED AT THIS TIME; ACCORDINGLY, THIS INVESTIGATION IS CLOSED.THE CLOSING OF THIS INVESTIGATION DOES NOT CONSTITUTE A FINDING BY NHTSA THAT NO SAFETY-RELATED DEFECT EXISTS.THE AGENCY RESERVES THE RIGHT TO TAKE FURTHER ACTION IF WARRANTED BY THE CIRCUMSTANCES.FOR ADDITIONAL INFORMATION SELECT DOCUMENT SEARCH.
EA04021 · Brake Lamp Failure
Opened Aug 3, 2004 · Closed Nov 4, 2004
Status: closed (inferred from source dates) · Exterior Lighting:brake Lights
GM STATES THAT SOME BRAKE/TAIL LAMP BULBS CAN PREMATURELY BECOME INOPERATIVE DUE TO MALFUNCTIONING BRAKE/TAIL LAMP SOCKETS.ON MARCH 2, 2004, GM INITIATED A 6-YEAR/72,000 MILE SPECIAL POLICY FOR 989,487 SUBJECT VEHICLES TO INSPECT AND REPLACE THE REAR BRAKE/TAIL LAMP BULB SOCKET ASSEMBLIES.ON APRIL 4, 2004, THE OFFICE OF DEFECTS INVESTIGATION (ODI) OPENED A PRELIMINARY EVALUATION (PE04-032) BASED ON CONSUMER COMPLAINTS ALLEGING BRAKE LIGHTS NOT OPERATING WHEN THE BRAKE PEDAL IS DEPRESSED.ON AUGUST 3, 2004 ODI UPGRADED PE04-032 TO AN ENGINEERING ANALYSIS (EA04-021).BY LETTER DATED OCTOBER 27, 2004 GM NOTIFIED NHTSA THAT IT WILL CONDUCT A SAFETY RECALL (NHTSA # 04V527) COVERING SUBJECT VEHICLES THAT WERE NOT ALREADY REPAIRED UNDER GM'S SPECIAL POLICY.MY 2004 SUBJECT VEHICLES BUILT AFTER AUGUST 8, 2003 CONTAIN IMPROVED BRAKE LAMP ASSEMBLIES AND ARE NOT INCLUDED IN THE RECALL.GM DEALERS WILL INSTALL THE IMPROVED BRAKE LAMP ASSEMBLY ON SUBJECT VEHICLES BUILT ON AUGUST 8, 2003 AND EARLIER.THE ACTION TAKEN BY GM IS SUFFICIENT TO RESOLVE THE ISSUES RAISED BY THIS INVESTIGATION.ACCORDINGLY, THIS INVESTIGATION IS CLOSED.
PE04032 · Brake Lamp Failure
Opened Apr 6, 2004 · Closed Aug 3, 2004
Status: closed (inferred from source dates) · Exterior Lighting:brake Lights
THE OFFICE OF DEFECTS INVESTIGATION (ODI) OPENED THIS INVESTIGATION ON MODEL YEAR (MY) 2002-04 CHEVROLET TRAILBLAZER VEHICLES.GM REPORTS THAT OTHER VEHICLES SHARING THIS PLATFORM AND BRAKE LAMP DESIGN ARE THE MY 2002-2004 CHEVROLET TRAILBLAZER EXT; GMC ENVOY, XL, XUV; OLDSMOBILE BRAVADA AND 2004 BUICK RAINIER.COMPLAINTS ALLEGE THAT THE REAR BRAKE LAMP DOES NOT OPERATE WHEN THE BRAKE PEDAL IS DEPRESSED.THERE IS NO INDICATION TO THE DRIVER FROM INSIDE THE VEHICLE THAT ONE OR MORE BRAKE LAMPS BULBS ARE NOT FUNCTIONING.GM FOUND THAT HEAT FROM THE BULB COULD DEFORM THE LAMP SOCKET, PRODUCE ELECTRICAL ARCING AND AN INOPERATIVE BULB.TO CORRECT THE CONDITION, GM CHANGED THE BULB TO A BULB THAT TRANSMITS LESS HEAT TO THE SOCKET AND CHANGED THE SOCKET TO A THERMOPLASTIC POLYMER TO IMPROVE THERMAL STABILITY.THESE CHANGES WERE IMPLEMENTED INTO PRODUCTION VEHICLES ON OCTOBER 1, 2003.GM IMPLEMENTED A SPECIAL POLICY BY NOTIFYING CONSUMERS THAT IF THEY SHOULD EXPERIENCE A BRAKE LAMP FAILURE TO GO TO THEIR GM DEALERSHIP TO HAVE THE CIRCUIT BOARD CONTAINING THE BRAKE LAMP REPLACED ALONG WITH NEW BULBS.THIS POLICY IS GOOD FOR THE FIRST 6 YEARS OR 72,000 MILES OF THE LIFE OF THE VEHICLE.ODI WILL UPGRADE THIS INVESTIGATION TO EA 04-021 AND INCLUDE THE ABOVE MENTIONED VEHICLES.