According to Au7o's research across NHTSA recalls, manufacturer TSBs, and owner forum reports, the 2006 Chevrolet Trailblazer has 16 documented known issues, with 4 rated critical. The most serious are TrailBlazer Headlamp Driver Module Failure — Safety Recall 15V519000, Driver's Door Master Power Window Switch Module Fire — Recall 14V404000 ($0-$0 repair), Power Steering Hose Fracture — Loss of Assist and Fire Risk (Recall 05V455000) ($0-$600 repair) and Electronic Throttle Body / TAC System Fault — 'Reduced Engine Power' with P2135 ($150-$700 repair). Across all issues with published estimates, repair costs range from $40 to $1,200. DIY maintenance guides at au7o.io.
General Motors LLC (GM) is recalling certain model year 2007 Pontiac Grand Prix, 2006-2009 Buick LaCrosse, 2006-2007 Buick Rainier, Chevrolet Trailblazer, GMC Envoy, 2006 Chevrolet Trailblazer EXT, GMC Envoy XL, 2006-2008 Isuzu Ascender, and Saab 9-7x vehicles. In the affected vehicles, the headlamp driver module (HDM) may overheat and fail, causing the headlamps and daytime running lights to not illuminate.
Campaign #15V51900014/08/2015
VISIBILITY:POWER WINDOW DEVICES AND CONTROLS
General Motors LLC (GM) is recalling certain model year 2005-2007 SAAB 9-7x; 2006 Chevrolet Trailblazer EXT and GMC Envoy XL; and 2006-2007 Chevrolet Trailblazer, GMC Envoy, Buick Rainier and Isuzu Ascender vehicles. Fluid may enter the driver's door master power window switch module, causing corrosion that could result in a short in the circuit board. A short may cause the power door lock and power window switches to function intermittently or become inoperative. The short may also cause overheating, which could melt components of the door module, producing odor, smoke, or a fire.
Campaign #14V40400002/07/2014
VISIBILITY:POWER WINDOW DEVICES AND CONTROLS
🔧
A mechanic who knows YOUR exact car
Answers tuned to your year, make, model & trim — not generic advice. Save your garage so it always has the right context.
Get ahead of Chevrolet Trailblazer problems — free
Leave your email and we'll alert you the moment there's a new recall or known issue for your Chevrolet Trailblazer. Free, no account needed.
What are the most common Chevrolet Trailblazer problems?
According to Au7o's research across NHTSA recalls, manufacturer TSBs, and owner forum reports, the 2006 Chevrolet Trailblazer has 16 documented issues. The most frequently reported are: TrailBlazer Headlamp Driver Module Failure — Safety Recall 15V519000, Driver's Door Master Power Window Switch Module Fire — Recall 14V404000, Power Steering Hose Fracture — Loss of Assist and Fire Risk (Recall 05V455000). Of these, 4 are rated critical and should be addressed promptly.
Is the Chevrolet Trailblazer reliable?
The 2006 Chevrolet Trailblazer has 16 known issues compiled from NHTSA recalls, manufacturer TSBs, and owner forum reports. 4 issues are rated critical: TrailBlazer Headlamp Driver Module Failure — Safety Recall 15V519000 and Driver's Door Master Power Window Switch Module Fire — Recall 14V404000 and Power Steering Hose Fracture — Loss of Assist and Fire Risk (Recall 05V455000) and Electronic Throttle Body / TAC System Fault — 'Reduced Engine Power' with P2135. Prospective buyers should inspect for these issues and factor potential repair costs into their purchase decision. Regular maintenance following the manufacturer's schedule helps prevent many common problems.
How much does it cost to fix common Chevrolet Trailblazer problems?
Repair costs for known Chevrolet Trailblazer issues range from $0 to $1,200, depending on the specific problem and whether you choose DIY or professional repair. Au7o provides step-by-step DIY maintenance guides that can help reduce repair costs.
What is the 2006-2007 Chevrolet Trailblazer TrailBlazer Headlamp Driver Module Failure — Safety Recall 15V519000?
Certain Chevrolet TrailBlazer SUVs are covered by GM safety recall 15V519000. The defect is in the headlamp driver module (HDM), the electronic module that drives the headlamp circuit: it can overheat and fail. Once it does, the TrailBlazer's headlamps and daytime running lights… Severity: high.
What is the 2006-2007 Chevrolet Trailblazer Driver's Door Master Power Window Switch Module Fire — Recall 14V404000?
Content on this page was compiled with AI assistance using NHTSA complaints, TSBs, owner reports, and public automotive data. While we strive for accuracy, this information may contain errors. Always verify repair procedures and specifications with your vehicle's service manual or a qualified mechanic.
Filter:
On the 2006-2007 Chevrolet Trailblazer, certain Chevrolet TrailBlazer SUVs are covered by GM safety recall 15V519000. The defect is in the headlamp driver module (HDM), the electronic module that drives the headlamp circuit: it can overheat and fail. Once it does, the TrailBlazer's headlamps and daytime running lights will not illuminate at all. NHTSA classifies this as a crash risk on two counts — the driver loses the ability to see the roadway, and the truck becomes far less visible to oncoming vehicles. The recall spans several GM-built and related SUVs (including the Envoy, Ascender and Saab 9-7X) for a campaign-wide total of about 429,170 vehicles.
Common Symptoms
Headlamps fail to illuminate
Daytime running lights inoperative
No low-beam or high-beam output
How to Fix
Dealers replace the headlamp driver module free of charge; there is no cost to the owner. Owner notification and the remedy started May 17, 2016 under GM recall number 14291. If you own one of these TrailBlazers, run the VIN at nhtsa.gov/recalls — that will show whether the HDM replacement is still outstanding on your specific truck.
On the 2002-2009 Chevrolet Trailblazer, on the body-on-frame GMT360 TrailBlazer, the instrument panel cluster uses six Switec XC5.168 stepper motors to drive the speedometer, tachometer, fuel, temperature, oil pressure and voltage needles. The motor gear teeth and solder joints degrade with heat cycling, so needles stick, read wildly wrong, sweep to the peg, drop to zero, or die entirely. It is one of the most heavily documented GM cluster defects of the era: NHTSA received large numbers of erratic-gauge complaints across GM's 2003-2007 line, and a 2008 class-action settlement (US District Court, Seattle) covered cluster replacement on qualifying GM vehicles including TrailBlazers. Owners also report dim or dead cluster backlighting from the same board. Because the speedometer can under-read, this is a safety-relevant failure, not merely a nuisance.
Common Symptoms
Speedometer reads far too high, too low, or not at all
Tachometer, fuel or temperature needle stuck or pegged
Gauges sweep erratically or drop to zero while driving
Needles dead on startup then come alive after driving
Dim or dead cluster backlighting
How to Fix
The class-action remedy has long since expired (it required the vehicle to be under 7 years / roughly 70,000-80,000 miles), so today the fix is at owner expense. The economical repair is to send the cluster to a rebuilder who replaces ALL six stepper motors with new Switec units and re-solders the board — replace all six even if only one gauge is bad, because they fail as a set. A used cluster is a poor substitute since it carries the same motors and requires odometer/VIN reprogramming by a dealer or locksmith. Rebuild service typically runs $100-250 plus a week of downtime; a new dealer cluster with programming is far more.
On the 2002-2009 Chevrolet Trailblazer, the cable-style window regulators in 2002-2009 TrailBlazers fail frequently. The plastic guide portion breaks, cables fray and wrap around the motor pulley, or the motor gears strip. Windows move slowly, make grinding/clicking noises, or become stuck. The front windows are most commonly affected. Lack of lubrication and debris in window tracks accelerate wear.
On the 2002-2006 Chevrolet Trailblazer, on affected GMT360 TrailBlazers the power steering hose can fracture under extreme steering maneuvers. Losing pressurized fluid means loss of power steering assist and, because the hydraulic system on these trucks also supports brake assist, reduced brake boost as well. Worse, fluid sprayed onto hot exhaust components can start an under-hood fire. GM issued NHTSA recall 05V455000 in October 2005. Separately from the recall, aging power steering hoses on this platform are a routine leak point that owners report as a cold-start whine and a puddle under the front of the truck.
Common Symptoms
Sudden loss of power steering assist
Hard steering effort during turns
Whine or groan from the power steering pump
Power steering fluid leak or under-hood fluid smell
Reduced brake pedal assist
How to Fix
Verify recall 05V455000 by VIN at NHTSA — the remedy is free at a Chevrolet dealer and never expires. Outside the campaign, replace weeping high-pressure and return hoses rather than topping off fluid, inspect where hoses route near the exhaust manifold, and clean any fluid off hot components. A steering system that groans, stiffens intermittently, or leaves fluid on the crossmember should be repaired promptly given the brake-assist and fire consequences.
On the 2002-2009 Chevrolet Trailblazer, the 2002-2009 TrailBlazer's intermediate steering shaft has a splined slip joint that loses its factory grease and begins to bind and release, transmitting a distinct clunk or knock up the column that the driver feels in the wheel — most obvious at low speed over driveways and speed bumps and when reversing direction on the steering wheel. GM addressed the condition on this family with a service bulletin covering lubrication of the intermediate shaft (TSB 02-02-35-006A), and it is one of the most-repeated complaints on GMT360 forums. It is a comfort/annoyance issue rather than a loss-of-control failure, but it must be distinguished from worn tie rods or a loose steering gear, which are not.
Common Symptoms
Clunk or knock felt in the steering wheel over bumps
Knock when changing steering direction at low speed
Noise from inside the column rather than the front suspension
Worse in cold weather
Noise reproducible by rocking the wheel while parked
How to Fix
First rule out real steering wear — tie rod ends, idler and pitman arms, and steering gear mounting bolts — because those clunk too and are safety items. If the noise traces to the intermediate shaft, the TSB remedy is to disassemble the slip joint and pack it with the specified grease; many owners find that temporary and simply replace the intermediate shaft assembly, which cures it permanently. Parts are inexpensive and the job is roughly an hour, with the steering wheel held straight so the clockspring is not damaged. No recall exists; the TSB repair is warranty-era only.
On the 2002-2009 Chevrolet Trailblazer, the GMT360 TrailBlazer uses a drive-by-wire throttle actuator control system with dual redundant sensors in both the throttle body and the accelerator pedal. When the two throttle position signals disagree the PCM sets P2135 and drops the truck into Reduced Engine Power limp mode — the vehicle will barely accelerate, which is dangerous when it happens pulling into traffic. Usual root causes are an internally failed electronic throttle body, a corroded or loose crimp in the throttle body connector, or moisture intrusion in the harness. Related codes P0641 (5V reference) and P1523 (throttle closed position performance) show up alongside it.
Do not simply throw a throttle body at it. Inspect the throttle body connector terminals for a loose crimp between the terminal and the copper strands and for green corrosion — a widely reported fix on this platform. Clean carbon from the throttle bore, since heavy buildup causes P1523. If the two TPS signals still fail to track on a scan tool, replace the electronic throttle body assembly (roughly $150-400 for the part) and relearn idle. If pedal position codes appear instead, the accelerator pedal position sensor assembly is the culprit. No recall covers this.
On the 2002-2009 Chevrolet Trailblazer 4.2L I6 LL8 Atlas, the 4.2L Atlas inline-six (LL8) used in the 2002-2009 GMT360 TrailBlazer has variable valve timing on the exhaust cam, controlled by an oil-fed camshaft position actuator solenoid mounted on the head behind the power steering pump. The solenoid screen clogs with oil varnish or the solenoid fails electrically, so the phaser will not hold commanded position. The PCM sets P0014 (exhaust cam timing over-advanced) or P0016 (cam/crank correlation) and the engine runs rough, idles poorly, and loses power. Owners also report the solenoid seeping oil down the back of the engine — it is the classic oil leak point on this engine. Note this is engine-code specific: it does not apply to the 5.3L V8 or the 6.0L SS.
Replace the exhaust camshaft position actuator solenoid with the updated GM part (12615873) and change the oil, since sludged oil is what clogs the screen. The solenoid is roughly $40-125; access requires unbolting and moving the power steering pump aside. If the code returns with a good solenoid, the cam phaser itself under the valve cover, or a worn timing chain, is the next suspect — a far larger job. Keeping the oil-change interval short is the real prevention. No recall or free remedy exists.
On the 2006-2007 Chevrolet Trailblazer, water running down the door glass enters the driver's door master power window switch module, corroding the circuit board and shorting the circuit. The short overheats and can melt the module, producing odor, smoke, or an actual fire — and it can happen while the vehicle is parked and switched off. GM recalled 2005-2007 Saab 9-7X; 2006 Chevrolet TrailBlazer EXT and GMC Envoy XL; and 2006-2007 Chevrolet TrailBlazer, GMC Envoy, Buick Rainier and Isuzu Ascender. GM initially handled it as a regional recall with a protective coating; that remedy proved insufficient and the campaign was expanded nationally in 2014. This is the switch module itself, not the window regulator/motor, and it is a fire risk.
Common Symptoms
Burning or electrical odor from the driver's door
Smoke from the driver's door armrest
Driver's master window switch works intermittently or not at all
Discolored or melted switch bezel
Fire in a parked vehicle
How to Fix
Free recall remedy: dealers inspect the part number on the driver's door module and install a new module where required, at no charge. Check the VIN on NHTSA's recall lookup — a twenty-year-old vehicle may have changed hands several times without the recall ever being performed, and the campaign has no expiration. Until the remedy is done, GM's own guidance was to park the vehicle outside. Any burning smell, smoke, or intermittent operation of all windows from the master switch should be treated as urgent.
On the 2002-2009 Chevrolet Trailblazer, the TrailBlazer uses an electronically controlled viscous fan clutch that fails, causing overheating in traffic or when towing. A failed fan clutch can also cause excessive fan engagement, creating a loud roaring noise and reduced fuel economy.
Common Symptoms
Overheating in traffic
Loud fan roar
A/C not cooling well
Poor fuel economy
How to Fix
Confirm fan clutch operation with a scan tool by comparing commanded fan speed to actual speed and checking for related DTCs such as P1481, P1482, P1484, or P0526, then inspect the fan clutch harness and connector for oil contamination or damaged wiring. If the clutch is stuck engaged, freewheeling, or not responding to PCM commands, replace the electronic viscous fan clutch assembly; on many TrailBlazers this is a bolt-on repair requiring fan shroud removal and a special fan clutch wrench/holding tool. After replacement, clear codes, verify fan engagement during warm idle and A/C operation, and confirm coolant temperature stays stable in traffic. Typical repair cost is about $300-$700 total depending on brand of clutch and labor time, with OEM-quality parts strongly recommended.
On the 2002-2009 Chevrolet Trailblazer 4.2L Atlas I6, the 4.2L Atlas I6 develops coolant leaks from the throttle body heater port, water pump weep hole, and thermostat housing. These are progressive leaks that worsen over time.
Pressure-test the cooling system and inspect the throttle body heater hoses/port, thermostat housing, and the water pump weep hole on the 4.2L Atlas I6; dried coolant residue below the pump pulley or around the throttle body usually confirms the source. Replace any leaking throttle body heater hose or fitting, the thermostat housing and seal if seepage is present, and the water pump if coolant is coming from the weep hole; on these engines it is also wise to install a new thermostat and fresh Dex-Cool coolant during service. After repair, vacuum-fill or properly bleed the system and verify fan clutch operation and operating temperature on a road test. Typical repair cost ranges from about $150-$300 for hoses or housing repairs, and roughly $500-$900 for a water pump replacement depending on labor rates and parts quality.
On the 2002-2009 Chevrolet Trailblazer, the 2002-2009 TrailBlazer and its GMT360 siblings are notorious for losing cabin blower speeds. Manual (slider) HVAC trucks use a resistor pack that burns out its lower-speed elements, leaving the fan working only on the highest setting. Automatic (digital display) HVAC trucks instead use an electronic blower control module whose power FET fails, which can leave the blower dead, stuck at one speed, or running with the key off. Aggravating factors are a worn blower motor drawing excess current and the connector overheating — a melted resistor connector is common enough that replacement kits ship with a new pigtail.
Common Symptoms
Blower only works on the highest fan speed
No air from vents at any speed
Blower stuck on and runs with ignition off
Burning smell from passenger footwell
Melted or discolored blower connector
How to Fix
Identify which system the truck has first: slider controls take the resistor pack, digital auto-climate takes the electronic blower control module. Both mount in the HVAC case on the passenger side under the dash and are a 20-40 minute job. Always inspect the connector — if the terminals are browned or melted, replace the pigtail too or the new part will cook. If the blower motor itself is noisy or drags, replace it at the same time; a failing motor is what kills resistors repeatedly. No recall covers this.
On the 2002-2009 Chevrolet Trailblazer, separate from the blower resistor, the GMT360 TrailBlazer uses several small plastic-geared HVAC actuators (driver temperature, passenger temperature, mode/direction, recirculation). A tooth strips off the final 'bull' gear inside the actuator and the motor then hunts back and forth, producing the signature repetitive clicking or ticking from behind the dash. Because driver and passenger temperature doors have their own actuators, the classic symptom is full heat on one side and cold air on the other. Some actuators are easy to reach; the mode actuator buried in the center of the HVAC case is the one owners dread.
Common Symptoms
Repetitive clicking or ticking behind the dash
Hot air from one side, cold from the other
Air will not switch between floor, vent and defrost
Recirculation stuck open or closed
Clicking that stops when the HVAC is turned off
How to Fix
Determine which actuator has failed by which function misbehaves (one-side temperature = that side's blend actuator; wrong vent selection or clicking on mode change = mode actuator). Replace the failed actuator — OEM or Dorman direct-fit units are inexpensive. Most GMT360 actuators can be reached by dropping trim panels rather than pulling the dash, but the center mode actuator is the hardest and is where most of the labor cost sits. After replacement the HVAC control head relearns door travel automatically or after a battery reset. No free remedy exists.
On the 2002-2009 Chevrolet Trailblazer, the thermal front axle disconnect actuator fails, preventing the front differential from engaging when 4WD is selected. The actuator uses a heat-activated element that cracks and leaks fluid internally. When it fails, the transfer case shifts but the front axle does not engage, leaving you effectively in 2WD.
Replace the thermal actuator with an upgraded unit. Some owners install a cable-operated manual actuator for more reliable engagement. Check the front differential fluid level — low fluid can also prevent smooth engagement. The actuator is located on the front axle housing and is accessible from underneath.
On the 2002-2009 Chevrolet Trailblazer, trailBlazer EXT (and the sibling Envoy XL/XUV, plus the TrailBlazer SS) fitted with the rear air-leveling option carry air-assisted rear shocks/bags fed by a small electric compressor and a height sensor. The rubber air bags crack with age and leak, the compressor's piston/head fails or its dryer saturates, and the 8-way compressor connector and relay corrode. The truck then sits low or crooked in the rear, rides harshly on bottomed shocks, and the compressor either runs continuously or never runs at all. This is option-specific — a base TrailBlazer with conventional coils and shocks is unaffected.
Common Symptoms
Rear of the vehicle sits low or sags overnight
Harsh, bottoming ride in the rear
Air compressor runs constantly or cycles repeatedly
Compressor never runs at all
Rear height changes when loaded and does not recover
How to Fix
Before buying parts, check under-hood fuse #1 and the rear-seat-area fuse #48, the compressor relay, and make sure the 8-way compressor connector is fully latched — a partially seated connector alone causes the no-lift complaint. If those are good, leak-test the bags with soapy water; cracked bags are the most common actual failure. Owners commonly replace air shocks and compressor as a set. A widely used alternative on high-mileage trucks is to delete the system and fit conventional coil-over rear shocks, which removes the failure mode permanently at the cost of self-leveling.
On the 2002-2009 Chevrolet Trailblazer, the GMT360 TrailBlazer uses a sealed front hub/bearing assembly with the ABS wheel speed sensor and tone ring built inside the unit — it cannot be serviced separately. When the bearing wears, the resulting play makes the internal tone ring wobble, so besides the growl and steering-wheel vibration the truck sets an ABS/traction light and the ABS can self-activate at low speed when it should not. Owners report replacements at intervals well under 100,000 miles, and the failure is aggravated by low-quality replacement hubs whose speed sensors are soft or incorrectly positioned.
Common Symptoms
Growling or humming that changes with speed and cornering
ABS and traction control warning lights on
ABS engages at very low speed for no reason
Play at the wheel when rocked at 12 and 6 o'clock
Steering wheel vibration
How to Fix
Diagnose with the wheel off the ground: check for bearing play at 12 and 6 o'clock and listen for a growl that changes when the vehicle is loaded in a turn. Replace the complete hub/bearing assembly — Timken, NAPA or ACDelco units hold up far better than budget imports, which frequently come back with an ABS light. Torque the hub retaining hardware to specification (about 103 lb-ft); over-torquing crushes the new bearing and it fails again quickly. Route and seat the ABS sensor lead carefully, since a pinched lead is the most common cause of an ABS light appearing right after a hub replacement.
On the 2002-2009 Chevrolet Trailblazer, the fuel level sender card inside the in-tank fuel pump module on the 2002-2009 TrailBlazer builds up sulfur/silver-sulfide deposits from non-Top-Tier gasoline, so the wiper loses contact with the resistor card. The gauge then reads empty with a full tank, sticks near full, jumps around while driving, or triggers a false 'Low Fuel' warning while the DIC range display goes useless. Owners have run out of fuel because of it. This is distinct from the cluster stepper-motor failure — if only the fuel gauge misbehaves and the others are fine, suspect the sender; if several gauges misbehave, suspect the cluster.
Common Symptoms
Fuel gauge stuck on empty or on full
Gauge needle jumps around while driving
False 'Low Fuel' warning light
Fuel range / DIC readout obviously wrong
Ran out of fuel with the gauge showing fuel remaining
How to Fix
Confirm with a scan tool: watch the fuel level sensor voltage/percentage while the gauge misbehaves — a sender fault shows nonsense values at the PCM, a cluster fault shows correct data with a wrong needle. The repair is to replace the fuel level sender or, on a high-mileage truck, the complete fuel pump module assembly since the pump is usually near the end of its life anyway. GM ran a special coverage policy on certain 2005-2007 vehicles that paid part of the fuel level sensor repair for 10 years/120,000 miles from in-service date — long expired, so verify status rather than assume coverage. Top Tier fuel or a Techron treatment slows deposit buildup but will not restore a worn card.
General Motors LLC (GM) is recalling certain model year 2006-2007 Buick Rainier, Chevrolet Trailblazer and GMC Envoy vehicles, and 2006 GMC Envoy XL and Chevrolet Trailblazer EXT vehicles. Fluid may enter into the driver's door master power window switch module, causing corrosion that could result in a short in the circuit board, causing window switches to become inoperative. Previously, the affected vehicles may have had their master power window switch module treated with a protective coating, instead of having it replaced.
Campaign #15V59900024/09/2015
ELECTRICAL SYSTEM
General Motors (GM) is recalling certain model year 2006 Chevrolet Trailblazer EXT and GMC Envoy XL and 2006-2007 Chevrolet Trailblazer, GMC Envoy, Buick Rainier, SAAB 9-7x, and Isuzu Ascender vehicles, originally sold or currently registered in Connecticut, Delaware, Illinois, Indiana, Iowa, Maine, Maryland, Massachusetts, Michigan, Minnesota, Missouri, New Hampshire, New Jersey, New York, Ohio, Pennsylvania, Rhode Island, Vermont, West Virginia, Wisconsin, and the District of Columbia. Fluid may enter the driver's door module, causing corrosion that could result in a short in the circuit board. A short may cause the power door lock and power window switches to function intermittently or become inoperative. The short may also cause overheating, which could melt components of the door module, producing odor, smoke, or a fire.
Campaign #12V40600016/08/2012
ELECTRICAL SYSTEM
General Motors (GM) is recalling certain model year 2005-2007 SAAB 9-7x; 2006 Chevrolet Trailblazer EXT and GMC Envoy XL; and 2006-2007 Chevrolet Trailblazer, GMC Envoy, Buick Rainier and Isuzu Ascender vehicles. Fluid may enter the driver's door module, causing corrosion that could result in a short in the circuit board. A short may cause the power door lock and power window switches to function intermittently or become inoperative. The short may also cause overheating, which could melt components of the door module, producing odor, smoke, or a fire.
Water running down the door glass enters the driver's door master power window switch module, corroding the circuit board and shorting the circuit. The short overheats and can melt the module, producing odor, smoke, or an actual fire — and it can happen while the vehicle is parke… Repairs typically run $0-$0. Severity: high.
What is the 2002-2006 Chevrolet Trailblazer Power Steering Hose Fracture — Loss of Assist and Fire Risk (Recall 05V455000)?
On affected GMT360 TrailBlazers the power steering hose can fracture under extreme steering maneuvers. Losing pressurized fluid means loss of power steering assist and, because the hydraulic system on these trucks also supports brake assist, reduced brake boost as well. Worse, fl… Repairs typically run $0-$600. Severity: high.
What is the 2002-2009 Chevrolet Trailblazer Electronic Throttle Body / TAC System Fault — 'Reduced Engine Power' with P2135?
The GMT360 TrailBlazer uses a drive-by-wire throttle actuator control system with dual redundant sensors in both the throttle body and the accelerator pedal. When the two throttle position signals disagree the PCM sets P2135 and drops the truck into Reduced Engine Power limp mode… Repairs typically run $150-$700. Severity: high.
What is the 2002-2009 Chevrolet Trailblazer Electric Fan Clutch Failure?
The TrailBlazer uses an electronically controlled viscous fan clutch that fails, causing overheating in traffic or when towing. A failed fan clutch can also cause excessive fan engagement, creating a loud roaring noise and reduced fuel economy. Repairs typically run $300-$700. Severity: medium.
What is the 2002-2009 Chevrolet Trailblazer 4.2L I6 Coolant Leak from Throttle Body and Water Pump?
The 4.2L Atlas I6 develops coolant leaks from the throttle body heater port, water pump weep hole, and thermostat housing. These are progressive leaks that worsen over time. Repairs typically run $200-$800. Severity: medium.
What is the 2002-2009 Chevrolet Trailblazer Front Axle Disconnect Actuator Failure?
The thermal front axle disconnect actuator fails, preventing the front differential from engaging when 4WD is selected. The actuator uses a heat-activated element that cracks and leaks fluid internally. When it fails, the transfer case shifts but the front axle does not engage, l… Repairs typically run $150-$400. Severity: medium.
What is the 2002-2009 Chevrolet Trailblazer 2002-2009 TrailBlazer (GMT360) Instrument Cluster Stepper Motor Failure — Dead or Wildly Wrong Gauges?
On the body-on-frame GMT360 TrailBlazer, the instrument panel cluster uses six Switec XC5.168 stepper motors to drive the speedometer, tachometer, fuel, temperature, oil pressure and voltage needles. The motor gear teeth and solder joints degrade with heat cycling, so needles sti… Repairs typically run $100-$600. Severity: medium.
What is the 2002-2009 Chevrolet Trailblazer Rear Air-Leveling Suspension Failure on EXT / SS — Rear End Sags and Compressor Runs Constantly?
TrailBlazer EXT (and the sibling Envoy XL/XUV, plus the TrailBlazer SS) fitted with the rear air-leveling option carry air-assisted rear shocks/bags fed by a small electric compressor and a height sensor. The rubber air bags crack with age and leak, the compressor's piston/head f… Repairs typically run $250-$1,200. Severity: medium.
What is the 2002-2009 Chevrolet Trailblazer 4.2L Atlas I6 (LL8) Exhaust Camshaft Position Actuator Solenoid Failure — P0014 / P0016?
The 4.2L Atlas inline-six (LL8) used in the 2002-2009 GMT360 TrailBlazer has variable valve timing on the exhaust cam, controlled by an oil-fed camshaft position actuator solenoid mounted on the head behind the power steering pump. The solenoid screen clogs with oil varnish or th… Repairs typically run $150-$600. Severity: medium.
What is the 2002-2009 Chevrolet Trailblazer Front Wheel Hub / Bearing Assembly Failure Corrupting the ABS Signal?
The GMT360 TrailBlazer uses a sealed front hub/bearing assembly with the ABS wheel speed sensor and tone ring built inside the unit — it cannot be serviced separately. When the bearing wears, the resulting play makes the internal tone ring wobble, so besides the growl and steerin… Repairs typically run $150-$600. Severity: medium.
What is the 2002-2009 Chevrolet Trailblazer Power Window Regulator Failure?
The cable-style window regulators in 2002-2009 TrailBlazers fail frequently. The plastic guide portion breaks, cables fray and wrap around the motor pulley, or the motor gears strip. Windows move slowly, make grinding/clicking noises, or become stuck. The front windows are most c… Repairs typically run $150-$500. Severity: low.
What is the 2002-2009 Chevrolet Trailblazer In-Tank Fuel Level Sender Fouling — Fuel Gauge Reads Empty, Full or Erratic?
The fuel level sender card inside the in-tank fuel pump module on the 2002-2009 TrailBlazer builds up sulfur/silver-sulfide deposits from non-Top-Tier gasoline, so the wiper loses contact with the resistor card. The gauge then reads empty with a full tank, sticks near full, jumps… Repairs typically run $250-$800. Severity: low.
What is the 2002-2009 Chevrolet Trailblazer GMT360 Blower Motor Resistor / Blower Control Module Failure — Fan Works Only on High or Not at All?
The 2002-2009 TrailBlazer and its GMT360 siblings are notorious for losing cabin blower speeds. Manual (slider) HVAC trucks use a resistor pack that burns out its lower-speed elements, leaving the fan working only on the highest setting. Automatic (digital display) HVAC trucks in… Repairs typically run $40-$250. Severity: low.
What is the 2002-2009 Chevrolet Trailblazer HVAC Blend / Mode Door Actuator Stripped Gear — Clicking Dash and Heat on One Side Only?
Separate from the blower resistor, the GMT360 TrailBlazer uses several small plastic-geared HVAC actuators (driver temperature, passenger temperature, mode/direction, recirculation). A tooth strips off the final 'bull' gear inside the actuator and the motor then hunts back and fo… Repairs typically run $60-$450. Severity: low.
What is the 2002-2009 Chevrolet Trailblazer Intermediate Steering Shaft Clunk — Knock in the Column Over Bumps and on Turn-In?
The 2002-2009 TrailBlazer's intermediate steering shaft has a splined slip joint that loses its factory grease and begins to bind and release, transmitting a distinct clunk or knock up the column that the driver feels in the wheel — most obvious at low speed over driveways and sp… Repairs typically run $50-$350. Severity: low.
