2008 Chevrolet Trailblazer Problems

What owners report

Owners of this model year most often describe electrical problems: intermittent no-starts tied to the ignition switch, window and door-module failures, and, in several complaints, smoke or fire at window switches, fuse boxes and the headlamp relay. Spontaneous side curtain airbag deployment while driving straight is also reported repeatedly, along with cracked exhaust manifolds. Many complaints come in between roughly 50,000 and 100,000 miles, and while some failures are gradual and intermittent, a number (fires, airbag deployments) are sudden and without warning.

1. 1
   Electrical system

   Intermittent no-start and stalling (ignition switch)

   • 17 complaints (9%)
   • median 71,000 mi at 6.6 yrs old (17 state mileage)
   • 1 mention a crash, fire or injury
   • filed 2014–2019

   Owners describe vehicles that will not crank or start, sometimes needing a boost, and other times stalling or losing power while driving with many dashboard warning lights lit. Several complaints say a mechanic or dealer diagnosed the ignition switch and replaced it, with some reporting the problem returned. Others describe the key sticking or turning in the ignition when no key is inserted. Reported from about 28,000 to 160,000 miles, with many cases in the 45,000-100,000 mile range and no clear weather pattern.

   1 related service bulletin

   What to check: Test cold and warm starts several times and ask whether the ignition switch or column has been replaced. A service bulletin describes diagnostics for intermittent no-crank or start-stall concerns with a security light.

   2 excerpts from owner complaints in NHTSA records

   “The ignition switch has been acting like the ones that are recalled with the 05 - 07 model years. Our vehicle when you turn the ignition on it acts like its dead, even with no key in ignition you can turn switch a little and the gear selector light comes on as well as the battery light, and we have had two dead batteries from this.”

   NHTSA complaint #10610548, filed 2014-07, 45,000 miles

   “While driving on a steep downhill curvy mountain pass, the key got jerked into the off position. Luckily I quickly restarted the engine. This is very dangerous on roads with a sharp incline and/or decline as one would need to be able to brake and steer the car into a safe area.”

   NHTSA complaint #10633290, filed 2014-09, 71,000 miles
2. 2
   Electrical system

   Window switches, door modules and electrical fires

   • 13 complaints (7%)
   • median 74,458 mi at 6.5 yrs old (13 state mileage)
   • 9 mention a crash, fire or injury
   • filed 2009–2022

   Complaints describe window switches that stop working, windows that roll down on their own, and door locks losing power, often after rain or when the door module gets wet. Several owners report a burning smell and find melted or charred wiring, a burned fuse box, or a fire in the door panel or at the headlamp relay; dealers are described as replacing window switch, door module or accessory board parts. Mostly reported from about 50,000 to 140,000 miles, with no single season dominating.

   2 related service bulletins

   What to check: Operate every window and lock from each door and check for a burning smell or discolored switches; ask whether door modules or switches have been replaced. A bulletin covers electrical ground repairs with updated fasteners.

   2 excerpts from owner complaints in NHTSA records

   “While sitting the parked vehicle, with the key in ignition in the on position but engine off the dash began to pour smoke into the vehicle. Upon inspecting under the hood there were burned and melted wires leading to fuse box. Electrical fire occurred.”

   NHTSA complaint #10584128, filed 2014-04, 110,000 miles

   “The contact owns a 2008 Chevrolet Trailblazer. While the vehicle was parked, the front passenger side window erroneously rolled down and an electrical burning odor was present inside the vehicle. While inspecting the vehicle, the contact discovered that the window switch was charred and melted. The cause of the failure was not diagnosed or repaired. The manufacturer was notified. The failure mileage was 139,000.”

   NHTSA complaint #10789880, filed 2015-11, 139,000 miles
3. 3
   Air bags

   Side curtain airbags deploying without a crash

   • 23 complaints (12%)
   • median 79,900 mi at 6.5 yrs old (18 state mileage)
   • 6 mention a crash, fire or injury
   • filed 2008–2026

   Owners report both side curtain airbags deploying while driving straight at ordinary speeds with no impact, sometimes with a white dust released into the cabin. Complaints describe dealers or investigators attributing it to a rollover event or road input, and owners say the vehicle was otherwise undamaged. Some also describe airbag and seat belt problems, including belts that no longer worked properly after deployment. Reported across a wide range, from very low mileage (under 2,000) up to about 160,000 miles, at speeds from about 20 to 65 mph.

   What to check: Check for an airbag warning light, look for replaced or mismatched trim above the windows, and ask whether any airbag deployment or sensor work was done. Expect a pre-purchase scan for stored airbag codes.

   2 excerpts from owner complaints in NHTSA records

   “On may 24, 2012- I was traveling out our mile long gravel driveway. Half way down the driveway the side curtain airbags on both sides deployed. There was no crash- they just came out. I contacted GM. They finally sent out a 3rd party investigator to investigate the vehicle. They determined that the vehicle had a roll-over event. The vehicle did not roll-over. Gm told me that it was an insurance issue. Insurance company says it is a mechanical issue and was GM's problem to fix. …”

   NHTSA complaint #10472374, filed 2012-08, 104,000 miles

   “While driving on a straight section of a city street at only 30 MPH both side curtain airbags deployed. I was startled but quickly looked around to see if I had hit anything or had been hit by another car. I was still moving forward and as soon as safely possible pulled the car over and got out to inspect what had happened. There was no collision with any other object or car and the airbags had deployed without warning. The airbag light had not been on and the car was driving normally. …”

   NHTSA complaint #10543828, filed 2013-09, 92,557 miles
4. 4
   Steering

   Stabilitrak light and loss of power when accelerating

   • 20 complaints (10%)
   • median 54,250 mi at 3.8 yrs old (20 state mileage)
   • filed 2010–2020

   Complaints describe the Stabilitrak or traction control light coming on, often during turns or over bumps, with the vehicle cutting power or hesitating for a few seconds when the driver tries to accelerate. Some owners say a steering angle sensor or wheel-speed sensor was diagnosed and replaced, and others report the light returning after repair. Mostly reported from about 15,000 to 130,000 miles, frequently at low speed in turns or on rough roads.

   1 related service bulletin

   What to check: Drive over bumps and make low-speed turns to see whether the light flashes or power drops; ask for any stored chassis or steering sensor codes. A bulletin covers a road-test vibration analysis procedure.

   2 excerpts from owner complaints in NHTSA records

   “Vehicles stabilitrac light comes on constantly. Repair listed for code is not the problem. Had same issue with my 2006 Trailblazer. Light comes on sporadically, even when backing out of my driveway at low rate of speed.”

   NHTSA complaint #10497612, filed 2013-02, 89,000 miles

   “While driving multiple times reaching a right hand curve at highway speeds the electronic stability control light flashes and the anti-lock brakes simultaneously engage multiple times sometimes bad enough to cause a wheel to slip. Dealer has been in touch multiple times with GM about the problem and claim they cant figure out what's wrong. Happens multiple times per week.”

   NHTSA complaint #10335855, filed 2010-06, 15,500 miles
5. 5
   Engine

   Cracked exhaust manifold and exhaust noise

   • 21 complaints (11%)
   • median 79,000 mi at 5.5 yrs old (19 state mileage)
   • filed 2009–2021

   Owners describe the exhaust becoming noticeably louder after startup or a cracked manifold found on inspection, sometimes with exhaust fumes entering the cabin in cold weather. Complaints say mechanics and dealers replaced the manifold, and one owner notes repeat replacements despite a changed part number. Typically reported between about 42,000 and 90,000 miles, with several owners mentioning fumes being worse in winter.

   1 related service bulletin

   What to check: Listen for a ticking or roaring exhaust note on a cold start and look for soot streaks or cracks at the manifold; ask whether it has been replaced. A bulletin covers identifying non-GM engine calibrations.

   2 excerpts from owner complaints in NHTSA records

   “With only 55,000 miles, the exhaust manifold cracked. Seeing all of the complaints online and talking to my mechanic, this seems to be a default part. Chevy should be recalling these. My mechanic had to order the part through the dealer and they had the replacement manifold in stock. Exhaust manifolds are not normally stock items unless there is a real high need to replace them.......”

   NHTSA complaint #10441026, filed 2011-12, 55,000 miles

   “The exhaust manifold in my 2008 chevy Trailblazer has broken now three times. The chevy dealer has changed the manifold twice for free but now they no longer want to pay for it plus I asked if they have made a change to the cast iron manifold and they tell me the part number changed in 2011 but my failures have occurred since then so I know the replacement manifold I will have the same problem. Exhaust fumes in winter enter the cabin.”

   NHTSA complaint #11397464, filed 2021-02, 128,000 miles

Buying note. Have a pre-purchase inspection scan for stored electrical, airbag and chassis codes, and budget for possible ignition switch or door-module work on a vehicle of this age. Confirm the exhaust manifold has been replaced and check that windows, locks and lights all work before buying.

Summary written with AI from a sample of 60 NHTSA complaints for this model year (picked at random, with complaints that state a mileage and recent ones taken first), then checked automatically against the source records. Where a problem shows a complaint count, every complaint for this model year was matched with fixed keyword rules (written with AI and tested against the sample), and the mileage, age and repair figures are calculated from those complaints; owners' figures are as stated, not verified. Other counts refer to the sample. The excerpts come from NHTSA's public complaint records and are unverified; capitalisation is normalised, NHTSA staff notes are removed, and shortened text ends with “…”. Something wrong? Request a correction.