The 2007 TrailBlazer on GMT360 platform is best known for catastrophic 4.2L I6 engine failures and transmission cooling issues. The inline-six became a time bomb after 100k miles, while even the 5.3L V8 models suffer from trans cooler and electrical gremlins.
4.2L I6 Vortec Catastrophic Engine Failure
Common · high severity
Typical onset: 100,000-150,000 mi
Symptoms: Sudden loss of oil pressure with no external leaks, Metallic knocking or rod bearing noise, Check engine light with low oil pressure codes, Coolant contamination in oil (milky dipstick)
Fix: Complete engine failure from spun rod bearings or crankshaft wear — most shops won't rebuild these due to weak bottom-end design. Typical fix is used or reman engine swap: 18-24 labor hours including R&R, fluids, and ancillaries.
Estimated cost: $4,500-7,500
Transmission Oil Cooler Line Failure and Cross-Contamination
Common · high severity
Typical onset: 80,000-130,000 mi
Symptoms: Transmission fluid in coolant reservoir (strawberry milkshake appearance), Coolant in transmission (burnt ATF smell, slipping), Sudden transmission overheating or failure after coolant leak
Fix: Internal radiator trans cooler fails, mixing ATF and coolant. Requires radiator replacement, trans flush (often full rebuild if coolant entered trans), and all cooler lines. If caught early: 6-8 hours. If trans damaged: add 12-16 hours for rebuild.
Estimated cost: $1,200-5,000
Transfer Case Encoder Motor and Mode Selection Failure
Common · medium severity
Typical onset: 70,000-110,000 mi
Symptoms: Service 4WD message on dash, Unable to shift into or out of 4WD modes, Grinding or clicking from transfer case area, Flashing 4WD selector lights
Fix: Encoder motor wears out or internal mode fork breaks. Motor alone: 2.5-3 hours. If internal fork damage exists, requires transfer case disassembly: 8-10 hours.
Estimated cost: $450-1,800
Fuel Pump and Sending Unit Failure
Common · medium severity
Typical onset: 90,000-140,000 mi
Symptoms: No-start or hard-start when hot, Erratic fuel gauge readings (often stuck on full), Engine stumbling or dying at highway speeds, Whining noise from fuel tank area
Fix: In-tank pump module fails; sending unit floats disintegrate. Requires tank drop and full pump/sender assembly replacement: 3.5-4.5 hours labor.
Estimated cost: $700-1,100
Front Differential Fluid Leak and Bearing Failure
Occasional · medium severity
Typical onset: 100,000-160,000 mi
Symptoms: Gear oil dripping from front diff area, Clunking on tight turns or acceleration, Howling or whining noise from front end, Vibration at highway speeds
Fix: Pinion seal leaks or carrier bearings wear. Seal job: 2-3 hours. Full bearing/seal overhaul: 6-8 hours with shim setup and backlash checks.
Estimated cost: $400-1,600
Electrical System: Battery Drain and BCM Faults
Occasional · medium severity
Symptoms: Dead battery after sitting overnight, Phantom electrical loads (lights, accessories staying on), Intermittent no-start with clicking, Radio or HVAC controls freezing or acting erratically
Fix: Body Control Module develops parasitic draw or relay failures. Diagnosis: 1-2 hours parasitic draw testing. BCM replacement/reprogramming if faulty: 2-3 hours total.
Estimated cost: $350-900
Rear HVAC Blower Motor and Resistor Failure
Occasional · low severity
Typical onset: 80,000-120,000 mi
Symptoms: Rear climate control blower inoperative, Only works on high speed, Burning smell from rear cargo area, Intermittent rear AC/heat function
Fix: Resistor board burns out or motor seizes. Requires interior panel removal in cargo area: 1.5-2 hours for resistor, 2.5-3 hours for motor.
Estimated cost: $250-550
Owner tips
If buying a 4.2L I6 model, budget for engine replacement — it's when, not if, past 100k miles
Check coolant and ATF religiously for cross-contamination every oil change
Replace transfer case encoder motor preemptively around 80k miles to avoid being stranded in 4WD
Use quality fuel and replace fuel filter every 30k to extend pump life
Only consider the 5.3L V8 version with documented trans cooler upgrade and full service records — the 4.2L I6 is a financial trap waiting to happen.
AI-assisted summary drawn from NHTSA recall data, our labor-times database, and platform knowledge. Not a substitute for a pre-purchase inspection on a specific vehicle.
Fitment notes: Side post terminals standard on GM trucks; located under hood
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Control Modules — 2007 Chevrolet TrailBlazer
Every control module on the 2002-2009 Chevrolet TrailBlazer — where it lives, replacement time, and what it takes to program a replacement. Modules marked dealer / factory tool won't work after a part swap alone — budget for programming.
Body Control Module (BCM)2.8 hr R&Rdealer / factory tool +0.8 hr▸ programming details
📍 Behind center of instrument panel, above center console, mounted to HVAC plenum bracket
🔧 Tech 2 + TIS2000/TIS2Web
⚠️ Controls lighting, door locks, remote keyless entry, retained accessory power. VIN programming and theft deterrent relearn required.
Transmission Control Module (TCM)2.5 hr R&Rdealer / factory tool +0.5 hr4L70E transmission only (2007-2009 V8 models)▸ programming details
📍 4L60E/4L65E: integrated within PCM (no separate module). 4L70E (2007-2009): standalone TCM mounted on driver side of transmission case
🔧 Tech 2 + TIS2000/TIS2Web
⚠️ Most TrailBlazers use PCM-integrated transmission control. Standalone TCM only on late 4L70E applications.
Transfer Case Control Module (TCCM)1.8 hr R&Rrelearn only +0.3 hr4WD/AWD models only▸ programming details
📍 Mounted on driver side of transfer case, near shift motor encoder
🔧 Tech 2 (encoder learn)
⚠️ Controls NVG 246 AutoTrac or NVG 149 transfer case. Encoder position relearn required after replacement.
Electronic Brake Control Module (EBCM)1.5 hr R&Rrelearn only +0.3 hr▸ programming details
📍 Engine compartment, driver side frame rail near master cylinder, integrated with hydraulic control unit (BPMV)
🔧 Tech 2 (automated bleed procedure)
⚠️ Includes StabiliTrak/traction control on equipped models. Brake system automated bleed required after replacement.
Remote Function Actuator (RFA)1.5 hr R&Rrelearn only +0.2 hr▸ programming details
📍 Driver and passenger door panels, integrated into door lock actuator assembly
📍 Integrated within BCM and ignition lock cylinder sensor (no standalone module)
⚠️ Passlock II system. Function integrated in BCM; ignition lock cylinder contains resistor pellet sensor. 10-minute relearn procedure required after BCM replacement or ignition cylinder service.
Aftermarket tool coverage varies by software version and vehicle build — treat "aftermarket tool" rows as "usually possible" and verify against your tool maker's coverage list before promising a customer. Spot a wrong location or hour? Tell us — corrections ship fast here.
VISIBILITY:POWER WINDOW DEVICES AND CONTROLS · 15V599000
2015-09-24
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.
Consequence: The protective coating may not eliminate the risk that the circuit board could short and result in a fire, even while the vehicle is unattended.
Remedy: GM will notify owners, and dealers will install a new driver's door switch module, free of charge. The recall began on November 2, 2015. Owners may contact Buick customer service at 1-800-521-7300, Chevrolet customer service at 1-800-222-1020, and GMC customer service at 1-800-462-8782. GM's number for this recall is 15700.
EXTERIOR LIGHTING:HEADLIGHTS · 15V519000
2015-08-14
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.
Consequence: Headlamps that do not illuminate reduce the driver's ability to see the roadway and reduce the vehicle's visibility to oncoming vehicles, both of which increase the risk of a vehicle crash.
Remedy: GM will notify owners, and dealers will replace the HDM, free of charge. The recall began on May 17, 2016. Owners may contact Buick customer service at 1-800-521-7300 or Pontiac customer service at 1-800-762-2737. GM's number for this recall is 14291.
VISIBILITY:POWER WINDOW DEVICES AND CONTROLS · 14V404000
2014-07-02
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.
Consequence: A short in the circuit board could lead to a fire, increasing the risk of personal injury. A fire could occur even while the vehicle is not in use. As a precaution, owners are advised to park outside until the remedy has been made.
Remedy: GM will notify owners, and dealers will inspect the part number on the door module, and install a new door module if necessary, free of charge. Parts for the remedy are not currently available. An interim letter was mailed to owners in August 2014. A second owner letter will be mailed when parts are available. Owners may contact GM customer service at 1-800-521-7300 (Buick), 1-800-222-1020 (Chevrolet), 1-800-462-8782 (GMC), 1-800-955-9007 (SAAB), and 1-800-255-6727 (Isuzu). GM's number for this recall is 14309. NOTE: This recall provides a new remedy for all vehicles covered by recall 13V-248. Vehicles whose modules were modified but not replaced as part of the previous recall remedy must have their vehicles remedied again under this campaign.
ELECTRICAL SYSTEM · 13V248000
2013-06-13 · EA12004
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.
Consequence: A short in the circuit board could lead to a fire, increasing the risk of personal injury. A fire could occur even while the vehicle is not in use. As a precaution, owners are advised to park outside until the remedy has been made.
Remedy: Owners will be contacted and dealers will test the driver's door module. If the module is functioning properly, a protective coating will be applied. If the module is not functioning properly, it will be replaced. These repairs will be done free of charge. GM will notify Buick, Chevrolet, and GMC owners, Isuzu and Saab will contact their respective owners. The recall began on August 2, 2013. Buick owners may contact the owner center at 1-800-521-7300, Chevrolet owners at 1-866-694-6546, GMC owners at 1-866-996-9463, Isuzu owners at 1-800-255-6727, and Saab owners at 1-800-955-9007. GM's campaign number is 12180. This recall is an expansion of recall 12V-406.
ELECTRICAL SYSTEM · 12V406000
2012-08-16 · EA12004
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.
Consequence: A short in the circuit board could lead to a fire, increasing the risk of personal injury. A fire could occur even while the vehicle is not in use. As a precaution, owners are advised to park outside until the remedy has been made.
Remedy: Parts for this recall are expected to available in March 2013. GM will notify Buick, Chevrolet, and GMC owners when parts are available. Buick owners may contact the owner center at 1-800-521-7300, Chevrolet owners at 1-866-694-6546, and GMC owners at 1-866-996-9463. Isuzu owners will be notified by Isuzu Motors when parts are available. Owners may contact Isuzu customer service at 1-800-255-6727. SAAB owners will be notified by SAAB Cars North America when parts are available and for inquiries, owners may call SAAB customer service at 1-800-955-9007.
Vehicle Info — 2007 Chevrolet TrailBlazer
Performance
Horsepower
300hp
Torque
330lb-ft
0–60 mph
7.8sec
Quarter mile
15.9sec
Top speed
112mph
Fuel economy (EPA)
City
14mpg
Highway
19mpg
Combined
16mpg
Fuel
Regular Gasoline
Capability & size
Towing capacity
6,200lb
Payload
1,290lb
Curb weight
4,750lb
Seating
7seats
EPA class
Sport Utility Vehicle - 4WD
Wiper blades
GMT360 platform SUV. Front wipers are same length on both sides
Size-standard part numbers — verify your connector type before buying. Rear blades are model-specific; check the package's vehicle list.
Fuel economy figures are EPA data via fueleconomy.gov (median across matching trims). Performance figures are compiled estimates for the 2007 Chevrolet TrailBlazer 5.3L V8 Vortec and can vary by trim.
🔧 Database maintained under the daily editorial review of Chris Hackleman · Master Technician · 20+ years.