2008 GMC Sierra Problems

What owners report

Owner complaints for this model year cluster around two things: the dashboard cracking above the passenger-side air bag, and power door locks that stop locking or unlocking. Air bag warning lights tied to corroded front crash sensors are the other frequently reported item. Reports span a wide mileage range, from a few thousand miles to well over 100,000, and many appear together with normal use rather than any single triggering event.

1. 1
   Latches, locks and linkages

   Power door locks stop locking or unlocking

   • 16 complaints (24%)
   • median 59,685 mi at 4.8 yrs old (12 state mileage)
   • filed 2011–2016

   Complaints describe one or more power door locks that stop responding to the key fob or the interior switch and only work by hand at the door. Owners report the problem moving from door to door over time, and dealers typically diagnosed failed lock actuators or lock assemblies, with some repairs covered under warranty and later ones charged to the owner. Several owners note the concern matters most when children are in the back seat or when a quick exit is needed. Typically reported between about 12,000 and 120,000 miles, with many under 60,000 miles.

   2 related service bulletins

   What to check: Cycle every door lock with the fob and the interior switches, including the rear doors, and ask whether any lock actuators have already been replaced.

   2 excerpts from owner complaints in NHTSA records

   “I have to lock and unlock both of my passenger side doors manually, because the locks doesn't work with the key fob nor inside the vehicle. I feel like this is a safety issue that GM should recognize because someone could have values stolen out of their vehicles if not have the vehicle stolen if they forget to manually lock doors when there is a passenger in the vehicle.”

   NHTSA complaint #10610121, filed 2014-07, 65,000 miles

   “My 2008 Gmc Sierra denali's automatic locks have failed on three of the four doors. I didn't realize they were not engaging until I took two children to dinner and had one of them open the door without unlocking the door. I had the child safety locks engaged and thought I would be safe, but it turns out the locks never engaged (thus, making the child locks irrelevant). This is an issue beyond inconvenience.”

   NHTSA complaint #10439683, filed 2011-12, 120,000 miles
2. 2
   Air bags

   Air bag inflator recall repairs not completed

   • 28 complaints (41%)
   • median 69,000 mi at 6.6 yrs old (19 state mileage)
   • 3 mention a crash, fire or injury
   • filed 2009–2021

   Several complaints describe receiving a Takata air bag inflator recall notice but being told the replacement part was unavailable, with no estimate for when it would arrive. A few owners report the air bag inflating or bursting unexpectedly, and others report air bags not deploying in a collision. The common thread in this group of complaints is the open recall and the parts delay rather than a separate part failure. Reported across a wide mileage range, from low-mileage trucks to ones over 150,000 miles.

   What to check: Check the vehicle's recall status by VIN with a dealer and confirm in writing that any open air bag inflator recall has actually been completed.

   2 excerpts from owner complaints in NHTSA records

   “Driver side air bag exploded. The bag itself did not deploy. Just a loud explosion filling the cab with black smoke. Violent blast of air/smoke against the driver. Would have been very serious if not driving at low speed on a side road at the time.”

   NHTSA complaint #10668222, filed 2014-12, 30,000 miles

   “On october 15, 2013, approx 7:45 am, single occupant, was entering the exit ramp from freeway when truck crashed and rolled twice. The air bags did not deploy. Truck was completely totaled. Occupant required medical transport to hospital and was kept for a week for testing and treatment for injuries. County sheriff attended to crash site and submitted traffic report. With all the recent recalls of GM products - like in other crashes, the air bags did not deploy. Ignition.”

   NHTSA complaint #10615324, filed 2014-07, 78,000 miles
3. 3
   Body and structure

   Dashboard cracks above passenger air bag

   • 12 complaints (18%)
   • median 59,000 mi at 6.6 yrs old (11 state mileage)
   • filed 2012–2016

   Owners describe cracks in the top of the dashboard, often starting above the passenger-side air bag area or near the instrument cluster hood and widening over time. Complaints say the cracks appear without an impact, sometimes while the truck sits parked, and some report the opening growing large enough to leave loose pieces. Owners frequently raise concern that sharp edges or broken plastic could affect air bag deployment; a number say the dealer quoted a replacement cost and did not cover it. Several complaints also tie the cracking to the air bag warning category because the cracks are located at the air bag opening. Reported from roughly 25,000 to 104,000 miles, usually without a collision or other trigger.

   What to check: Inspect the dash top around the passenger air bag and the instrument cluster hood for cracks or repaired panels; ask whether the dashboard has been replaced and whether the air bag warning light has ever been on.

   2 excerpts from owner complaints in NHTSA records

   “The safety during a collision or airbag deployment from sharp plastic exposed due to the cracks in the dash cutting the airbag or shards of plastic becoming projectiles potentially causing injury to occupants. I just had a phone conversation with someone over at GM and they are going to contact the dealership regarding this issue. I explained to them this is a major safety concern. …”

   NHTSA complaint #10564952, filed 2014-02, 55,000 miles

   “My Sierra has the same problem that many other GM vehicles have. The dash is cracking, creating loose pieces. It is cracked at the airbag. This sharp edges could impair the proper function of the airbag. In the event of an accident, I am afraid the loose dash pieces could post a danger to the vehicles occupants.”

   NHTSA complaint #10825428, filed 2016-02, 64,000 miles
4. 4
   Air bags

   Air bag warning light from corroded front crash sensors

   • 11 complaints (16%)
   • median 76,767 mi at 7.0 yrs old (11 state mileage)
   • filed 2011–2021

   Owners report the service air bag message and warning light coming on with no crash, and dealers diagnosing corroded or water-intruded front impact sensors that shut down the air bag system. Complaints describe the sensors as sealed units that nonetheless showed corrosion and swelling, and note the repair is charged per sensor plus labor. Some owners say the dealer warned the system might not deploy in a crash until the sensor was replaced. Mostly reported between about 33,000 and 108,000 miles, including several cases under 60,000 miles.

   What to check: Ask whether the front air bag sensors have been replaced and whether the air bag warning light is currently off; a scan for air bag system codes before purchase is worthwhile.

   2 excerpts from owner complaints in NHTSA records

   “My vehicle air bag sensors have been diagnosed as faulty. The dealership indicated that both front air bag sensors are part of a known problem where the factory tightened the bolts too far making the sensors prone to crack and collect moisture. This moisture then freezes and the sensors need to be replaced. This repair is very costly at over $200 per sensor and both sensors need replaced. This doesn't include labor. This is definitely a safety issue and I don't know if the air bags will function properly if an accident were to happen. …”

   NHTSA complaint #10689578, filed 2015-02, 33,635 miles

   “Warning light came on about air bag, took to Gmc dealer as Gmc had no recall on this warning Gmc dealer ran test determined the passenger air bag sensor had corroded and I had to replace it and it was not cov by warranty, so pd 317.00 to have replaced. Something this important in the vehicle should have been recalled and sensor moved to other location as it was corroded from weather? …”

   NHTSA complaint #10615045, filed 2014-07, 108,787 miles
5. 5
   Electrical system

   Electrical faults and intermittent no-crank

   Mentioned in 6 of 60 sampled complaints

   Complaints describe repeated electrical symptoms: warning messages such as service traction control and service StabiliTrak, gauges and warning lights cycling, radio resets, and in some cases the engine losing power or shutting off. Owners also report the truck starting or running on its own overnight, with headlights flashing, and multiple complaints concern the heated washer fluid system recall, where owners said the remedy was to disable or remove the feature rather than replace it. Reported mostly between about 63,000 and 78,000 miles, plus recall-related complaints at unknown mileage.

   Recall 08V441000Recall 10V2400004 related service bulletins

   What to check: Ask whether the heated washer fluid recall remedies have been applied and have the charging system and battery connections checked; note any warning lights that appear during a test drive.

   2 excerpts from owner complaints in NHTSA records

   “On the morning of april 11 we had a severe thunderstorm at approx. 3:00am. Later in the morning at approximately 6:30am I found my 2008 Sierra truck running in my garage with the garage doors shut. The headlights were flashing and the garage was extremely hot due to the engine running. There was a lot of water condensation on the floor indicating that the engine had been running for quite some time. The temperature gauge was at running temperature. …”

   NHTSA complaint #10508300, filed 2013-04, 71,500 miles

   “This is not an official complaint however as the ignition problem unfolds with the GM products I wanted to take the opportunity to bring to the attention a very serious problem that occurred approximately a year or so ago with my 2008 Gmc Sierra. I typically park my truck in the garage with the key in the ignition. We have a live camera in the garage and one morning around 7 am after a severe thunderstorm around 3 am I found on the camera the truck running with flashing headlights. …”

   NHTSA complaint #10568315, filed 2014-03

Buying note. Check the dashboard around the passenger air bag for cracks, test every power door lock with the fob and the switches, and confirm with a dealer by VIN that any open air bag inflator recall has been completed. An air bag system scan and a look at the front crash sensors are worth the cost 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.