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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.

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When problems were reported

Mileage at the reported incident

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 reports
65,120 miles · Jun 15, 2010
Exterior Lighting

I HAVE A 2004 CHEVROLET TRAILBLAZER AND HAVE HAD TO HAVE BOTH HEADLIGHTS REPLACED SEVERAL TIMES OVER THE PAST YEAR. MY DEALERSHIP HAS SAID THIS IS A RECURRING PROBLEM THEY HAVE BEEN EXPERIENCING WITH TRAILBLAZERS THAT ARE BROUGHT IN. *TR

NHTSA ODI #10336501

37,000 miles · Jun 14, 2010
Electrical System

TRAILBLAZER REFUSED TO CHARGE THE BATTERY ON THE TRAVEL TRAILER. THE DASH LIGHTS OCCASIONALLY FLICKERED, THEN CAME BACK ON STRONG. GM DEALER COULD NOT FIND THE PROBLEM. A LOCAL MECHANIC SIMPLY TOOK THE COVER OFF THE ELECTRICAL DISTRIBUTION BOX AT THE FRONT RIGHT OF THE ENGINE, THEN PUSHED ALL THE WIRES DEEPER INTO THEIR CONTACT …

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TRAILBLAZER REFUSED TO CHARGE THE BATTERY ON THE TRAVEL TRAILER. THE DASH LIGHTS OCCASIONALLY FLICKERED, THEN CAME BACK ON STRONG. GM DEALER COULD NOT FIND THE PROBLEM. A LOCAL MECHANIC SIMPLY TOOK THE COVER OFF THE ELECTRICAL DISTRIBUTION BOX AT THE FRONT RIGHT OF THE ENGINE, THEN PUSHED ALL THE WIRES DEEPER INTO THEIR CONTACT SOCKETS. THAT RESOLVED THE PROBLEMS, AT LEAST UNTIL NOW. NOW THE SERVICE ENGINE LIGHT IS ON AGAIN, AND IT SAYS IT IS FOR THE PRESSURE SYSTEM. *TR

NHTSA ODI #10336180

110,000 miles · Jun 14, 2010
Electrical System

SPEEDOMETER GAUGE ONLY WORKS CORRECTLY INTERMITTENTLY. NUMEROUS GAUGE PROBLEMS AND NUMEROUS HEADLIGHT FAILURES. *TR

NHTSA ODI #10336121

Mileage unknown · Jun 11, 2010
Electrical SystemExterior Lighting

THERE ARE SEVERAL DEFECTS ON CHEVY TRAIL BLAZERS MINE IN PARTICULAR IS WITH THE INSTRUMENT CLUSTER PANEL BECAUSE IT STOPPED RECORDING THE SPEED, AMOUNT OF GAS IN MY VEHICLE, ESSENTIAL TO DRIVING SAFETY, PROPER SPEED MAINTENANCE AND ENSURING IT WONT STALL OUT DUE TO LACK OF GAS IN THE VEHICLE WHILE ON THE FREEWAY AT HIGH SPEEDS. …

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THERE ARE SEVERAL DEFECTS ON CHEVY TRAIL BLAZERS MINE IN PARTICULAR IS WITH THE INSTRUMENT CLUSTER PANEL BECAUSE IT STOPPED RECORDING THE SPEED, AMOUNT OF GAS IN MY VEHICLE, ESSENTIAL TO DRIVING SAFETY, PROPER SPEED MAINTENANCE AND ENSURING IT WONT STALL OUT DUE TO LACK OF GAS IN THE VEHICLE WHILE ON THE FREEWAY AT HIGH SPEEDS. IN ADDITION THE NIGHT LIGHTS TURN OFF RANDOMLY WHILE DRIVING AT NIGHT AND THAT IS DANGEROUS TO ME AND MY CHILDREN WHEN DRIVING AT NIGHT WHICH I DO OFTEN TO COMMUTE HOME FROM WORK. THERE ARE DIFFERENT DATES FOR THE DEFECTS THE CLUSTER PANEL GAGE WAS PROXIMATELY 6 OR 8 MONTHS OLD, THE MANUFACTURER WAS CONTACTED THEY STATED IT WAS NOT HAZARDOUS TO MY DRIVING AND THAT SINCE IT WAS NOT UNDER WARRANTY DUE TO BEING A 2004 THE BEST THEY COULD DO WAS 10% OFF, I FELT IT WAS A HAZARD AT THE TIME OF THE REPORT THEY FIXED AN ISSUE WITH THE TURN SIGNALS BUT NOW MY HEADLIGHTS ARE TURNING ON AND OFF RANDOMLY AT NIGHT AND IT IS SCARY TO BE DRIVING AT NIGHT AND YOUR LIGHTS GO OFF AND YOU CANT SEE A THING. THE LIGHTS HAVE BEEN MALFUNCTIONING FOR THE LAST 3 TO 4 MONTHS HAVE NOT REPORTED IT BECAUSE OF THE LACK OF RESPONSE BY THE MANUFACTURER WITH PRIOR ISSUE. *TR

NHTSA ODI #10335862

101,021 miles · Jun 10, 2010
Engine And Engine Cooling

CRACKED EXHAUST MANIFOLD . NOTHING CAUSED THIS EVENT , IT JUST FAILED OUT OF NOWHERE, NOW IT HAS TO BE REPLACED , THIS IS AN UNCOMMON EVENT FOR THIS PARTICULAR PART TO JUST CRACK OR FAIL , AND AFTER READING RESEARCHING THIS EVENT I FOUND IT TO BE MORE COMMONPLACE IN THIS FROM THIS PARTICULAR CAR MANUFACTURER. THE FUMES FROM THE …

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CRACKED EXHAUST MANIFOLD . NOTHING CAUSED THIS EVENT , IT JUST FAILED OUT OF NOWHERE, NOW IT HAS TO BE REPLACED , THIS IS AN UNCOMMON EVENT FOR THIS PARTICULAR PART TO JUST CRACK OR FAIL , AND AFTER READING RESEARCHING THIS EVENT I FOUND IT TO BE MORE COMMONPLACE IN THIS FROM THIS PARTICULAR CAR MANUFACTURER. THE FUMES FROM THE EXHAUST MANIFOLD IS THE SAFETY ISSUE , NOT TO MENTION THE UNBEARABLE NOISE. *TR

NHTSA ODI #10335631

58,000 miles · Jun 8, 2010
Electrical System

TL* THE CONTACT OWNS A 2004 CHEVROLET TRAILBLAZER. THE CONTACT STATED THAT THE AIR BAG WARNING LIGHT WOULD INTERMITTENTLY ILLUMINATE AND THE RPM GAUGE WOULD CONTINUE TO FLUCTUATE BETWEEN RPMS. THE DEALER PERFORMED A DIAGNOSTIC AND FOUND THAT THE INSTRUMENT PANEL WAS FAILING. THE VEHICLE WAS NOT REPAIRED. IN ADDITION, THE CONTAC…

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TL* THE CONTACT OWNS A 2004 CHEVROLET TRAILBLAZER. THE CONTACT STATED THAT THE AIR BAG WARNING LIGHT WOULD INTERMITTENTLY ILLUMINATE AND THE RPM GAUGE WOULD CONTINUE TO FLUCTUATE BETWEEN RPMS. THE DEALER PERFORMED A DIAGNOSTIC AND FOUND THAT THE INSTRUMENT PANEL WAS FAILING. THE VEHICLE WAS NOT REPAIRED. IN ADDITION, THE CONTACT STATED THE SEAT BELTS WOULD NOT OPERATE AND THE INSTRUMENT PANEL COMPLETELY FAILED. THE FAILURE MILEAGE WAS 58,000 AND THE CURRENT MILEAGE WAS 73,000.

NHTSA ODI #10335199

52,000 miles · Jun 7, 2010
Electrical SystemCrash

2004 CHEVY TRAILBLAZER INSTRUMENTATION PANEL CLUSTER OUT SPEEDOMETER GAS OIL PRESSURE BATTERY AND RPM. 2 SPEEDING TICKETS. SPEEDO WAS OFF BY 40 AT THE TIME,NOW DOES NOT WORK AT ALL. NO GAS ON FREEWAY. AND BATTERY OUT CAUSED A CRASH. CHEVY DEALERSHIP REFUSES TO HELP ALTHOUGH THERE IS A RECALL FOR OTHER CHEVY PRODUCTS WITH SIMILAR…

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2004 CHEVY TRAILBLAZER INSTRUMENTATION PANEL CLUSTER OUT SPEEDOMETER GAS OIL PRESSURE BATTERY AND RPM. 2 SPEEDING TICKETS. SPEEDO WAS OFF BY 40 AT THE TIME,NOW DOES NOT WORK AT ALL. NO GAS ON FREEWAY. AND BATTERY OUT CAUSED A CRASH. CHEVY DEALERSHIP REFUSES TO HELP ALTHOUGH THERE IS A RECALL FOR OTHER CHEVY PRODUCTS WITH SIMILAR PROBLEMS. CHEVY SERVICE DEPARTMENT OFFERS NOTHING AND REFUSES TO HELP OR ACKNOWLEDGE ANYTHING WRONG. THIS IS A SAFETY PROBLEM I AM NOT THE ONLY ONE HAVING THIS PROBLEM. PLEASE HELP FORCE GM TO RECALL THE INSTRUMENT CLUSTER PANEL. *TR

NHTSA ODI #10335124

70,000 miles · Jun 7, 2010
Electrical System

MY WIFE OWNS A 2004 CHEVY TRAILBLAZER AND THE INSTRUMENT CLUSTER IS GOING HAYWIRE. WE HAVE ALREADY SPENT HUNDREDS OF DOLLARS TAKING IT TO THE DEALERSHIP TO HAVE IT FIXED WITH NO SUCCESS. I AM A PRETTY GOOD MECHANIC, BUT NOT WHEN IT COMES TO ALL THE ELECTRONICS ON CARS THESE DAYS. I REFUSE TO TAKE IT BACK AND GET SCREWED OUT OF M…

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MY WIFE OWNS A 2004 CHEVY TRAILBLAZER AND THE INSTRUMENT CLUSTER IS GOING HAYWIRE. WE HAVE ALREADY SPENT HUNDREDS OF DOLLARS TAKING IT TO THE DEALERSHIP TO HAVE IT FIXED WITH NO SUCCESS. I AM A PRETTY GOOD MECHANIC, BUT NOT WHEN IT COMES TO ALL THE ELECTRONICS ON CARS THESE DAYS. I REFUSE TO TAKE IT BACK AND GET SCREWED OUT OF MORE MONEY. I GUESS THIS IS HOW CHEVROLET IS MAKING UP FOR THEIR LOSS. I STILL CAN'T BELIEVE THAT THERE IS NOT A RECALL ON THIS AS OF YET. THE INTERNET IS LOADED WITH COMPLAINTS WITH THIS ISSUE. I HAVE ALWAYS BEEN A CHEVY MAN, BUT IT LOOKS LIKE I MAY END UP CHANGING MY LOYALTY TO ANOTHER COMPANY. WITH AS MUCH AS WE HAVE TO PAY FOR VEHICLES THESE DAYS WE SHOULD BE RECEIVING BETTER SERVICE ON THEM. I WILL BE BUYING A USED CLUSTER OFF THE INTERNET AND INSTALLING IT MYSELF. THE DEALERSHIP EVEN WANTS A FORTUNE TO REPLACE A PART THEY SHOULD HAVE A RECALL ON ANYWAY. *TR

NHTSA ODI #10334964

Mileage unknown · Jun 4, 2010
Electrical System

HAVING TROUBLES WITH MY 2004 CHEVY TRAILBLAZER GAUGE CLUSTER. WHICH WORKED SPORADICALLY THEN FINALLY HAS STOPPED WORKING COMPLETELY. THIS SEEMS TO BE A COMMON UNSAFE PROBLEM IN THESE VEHICLES. AND THERE IS NO RECALL ON THIS PARTICULAR MODEL. BUT CHEVY DOES BACK ITS OTHER MODELS FOR THIS SAME PROBLEM. THIS IS A MAJOR UNSAFE VEHI…

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HAVING TROUBLES WITH MY 2004 CHEVY TRAILBLAZER GAUGE CLUSTER. WHICH WORKED SPORADICALLY THEN FINALLY HAS STOPPED WORKING COMPLETELY. THIS SEEMS TO BE A COMMON UNSAFE PROBLEM IN THESE VEHICLES. AND THERE IS NO RECALL ON THIS PARTICULAR MODEL. BUT CHEVY DOES BACK ITS OTHER MODELS FOR THIS SAME PROBLEM. THIS IS A MAJOR UNSAFE VEHICLE MISHAP. AND THERE NEEDS TO BE A RECALL PLACED ON IT!!! *TR

NHTSA ODI #10334630

Mileage unknown · Jun 1, 2010
Electrical SystemElectronic Stability Control (esc)

ALL GAUGES ON CONTROL PANEL NOT WORKING, BUT ALL SERVICE LIGHTS COME ON CHECK ENGINE, ABS SEAT BELT, REDUCE POWER, BATTERY LIGHTS. NOW SUV NOT CRANKING, IT WILL SPIN BUT NOT TURNING OVER. WILL CRANK UP AFTER LETTING IT SIT FOR A WHILE. I RECEIVED A TICKET FOR SPEEDING, ALREADY. *TR

NHTSA ODI #10334159

Official recalls

2

05V198000 · 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

4

RQ17002 · 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.