2006 GMC Sierra 1500 Problems

What owners report

Complaints on this model year center on the brake system: owners most often describe rusted steel brake lines that leak or burst, and unwanted ABS activation at low speed that lengthens stopping distance. Electrical trouble with the HVAC blower motor resistor and its wiring connector is the next most frequent theme, followed by transmission and four-wheel-drive complaints. Many reports come from relatively low-mileage trucks, and the brake-line reports cluster in vehicles kept in areas with road salt.

1. 1
   Brakes

   Rusted steel brake lines leaking or bursting

   • 28 complaints (19%)
   • median 77,000 mi at 9.1 yrs old (27 state mileage)
   • 1 mention a crash, fire or injury
   • owner-quoted repair $1,079 (median of 8 quotes)
   • filed 2011–2020

   Owners describe brake fluid leaking from steel lines that have rusted through, often where a clip or fitting holds the line, and sometimes noticing fluid spraying near the engine or exhaust. In several reports the pedal went to the floor while braking at low speed or on a driveway, and drivers used the parking brake to stop. Complaints say dealers quoted full replacement of all four lines, and some owners report the dealer or manufacturer described the corrosion as normal and not covered. Reported from as low as roughly 29,000 miles up into the 130,000-mile range, frequently on trucks parked outside in regions that use road salt.

   What to check: Have a mechanic inspect the steel brake lines along the frame and above the rear axle for rust and wet spots before buying; ask for records of any line replacement.

   2 excerpts from owner complaints in NHTSA records

   “Pulling out of driveway and brakes gave out.. Stepped on the brakes and truck did not stop. A rusty brake line was leaking. It it had a split in it. Do to rust anand corrosion. This same thing has happened to my father's 03 silverado a few years back. Why has this been an issue with no recall. I had a kia spectra for 15 years and never had problems with rusty brake lines leaking... It's a truck they should be built to last.. Smh not happy..”

   NHTSA complaint #10761547, filed 2015-09, 130,000 miles

   “I had just replaced the third set of wheel bearings, asked my wife to hold brake so that I could torque axel nut. When she pushed the brake pedal, I seen brake fluid pouring down the frame of truck. Checked lines all were rusted very bad. Called matheny motors of parkersburg wv. The cost of replacement of lines was quoted at over $1200.00 I can not express enough how upset I am that this safety item was not made of stainless steel on a vehicle that was at the cost of almost $40,000.00.”

   NHTSA complaint #10683771, filed 2015-02, 102,000 miles
2. 2
   Brakes

   ABS activating at low speed, longer stops

   • 19 complaints (13%)
   • median 38,643 mi at 5.7 yrs old (17 state mileage)
   • filed 2009–2018

   Owners describe the ABS kicking in while braking below about 10-20 mph, with a grinding or popping pedal feel and noticeably longer stopping distance, including in driveways, parking lots and crosswalks. Some report the ABS light never comes on, and diagnosis varies: debris in the rear drums, failed wheel hub assemblies, or a faulty ABS unit were cited by mechanics. Dealer responses described in complaints ranged from rotor resurfacing to saying the condition was normal wear. Commonly reported between roughly 15,000 and 75,000 miles, and many owners note it happens repeatedly at low speed rather than at highway speeds.

   2 related service bulletins

   What to check: Test drive at walking pace in a parking lot and feel for the pedal pulsing or pushing back; ask whether the ABS sensors, wheel hubs and rear brake hardware have been serviced.

   2 excerpts from owner complaints in NHTSA records

   “2006 Gmc 1500 sierra with 16,734 miles, the ABS system engages around 5 MPH and when the truck will actually stop is any one's guess. Very dangerous in parking lots, and around pedestrians as well as normal driving. I see there are thousands of similar complaints on the web. Please put my tax dollars to work and do something. Thank you.”

   NHTSA complaint #10374692, filed 2011-01, 14,525 miles

   “The ABS activates when it isn't supposed to. Backing out of my driveway the brake drops, grunts, and takes far too long to stop. Also when turning this occurs. Gmc had a recall for the exact same thing for the model years 1999-2002 starting in 2005. They say it's from normal wear and tear, but not one other truck or SUV owner I've ever known has had a similar problem, with a different company. They even offered to pay for part of it, citing the recall accidentally. This is a very dangerous defect, and something needs to be done about it. …”

   NHTSA complaint #10324044, filed 2010-04, 30,000 miles
3. 3
   Brakes

   Brake pedal pulsation and rotor vibration

   • 19 complaints (13%)
   • median 38,643 mi at 5.7 yrs old (19 state mileage)
   • filed 2006–2018

   Owners report vibration or pulsing through the pedal and steering wheel when braking, which dealers typically addressed by resurfacing or replacing rotors, sometimes repeatedly at fairly short intervals. Some also describe rear brake noise that returned after resurfacing. Complaints frame it as a recurring annoyance rather than a one-time repair. Reported from around 10,000 to 60,000 miles, often with the vibration returning within 10,000-15,000 miles of the previous repair.

   What to check: Brake firmly from moderate speed during the test drive and check for pedal or wheel shake; ask how recently pads and rotors were replaced.

   2 excerpts from owner complaints in NHTSA records

   “2006 Gmc sierra brake issues. Rotors have been turned 6 plus times in 90k miles. Brakes squeak, pulsate, and vibrate continuously. Dealer has checked multiple times and advised that I just need my rotors turned.”

   NHTSA complaint #10265181, filed 2009-04, 30,000 miles

   “Since roughly june of 2014 complete vehicle shakes violently when brakes are applied. I have had it looked at and have been told that it is the brake lines ABS and needs replacement. I am a single father of two boys struggling financially and cannot afford new brake lines. I also have a current situation where the rear bumper is completely rotted through and as a result cannot pass state vehicle inspection I have searched for 2 months and cannot find a used rear bumper and manufacturer cost is $450-$500 which I cannot afford at the moment. …”

   NHTSA complaint #10664593, filed 2014-12, 77,000 miles
4. 4
   Electrical system

   HVAC blower resistor and harness melting

   • 12 complaints (8%)
   • median 60,000 mi at 5.0 yrs old (11 state mileage)
   • 2 mention a crash, fire or injury
   • filed 2006–2020

   Owners describe the blower motor stopping, especially on high speed, and sometimes smoke or a burning smell from the resistor or the connector on the wiring harness. Complaints note melted connectors and harness plugs that could not be separated, and one describes the resistor overheating and fusing to the wiring. Dealers replaced resistors, harnesses and blower components, with some owners reporting repeat failures. Reported from about 6,000 miles up to roughly 110,000 miles, with several reports on trucks around 55,000-90,000 miles.

   2 related service bulletins

   What to check: Run the fan through every speed setting with the engine running and smell for hot plastic near the passenger footwell; ask whether the blower resistor and harness connector have been replaced.

   2 excerpts from owner complaints in NHTSA records

   “My fan high speed burst out and I had a strong else trial burning smell. I had my truck looked at to find that my wiring harness and resistor had burnt. I had them replaced this last september. Since then I have had to replace two more resistors and one more wiring harness. I talked to two dealerships and no one told me about the, special warranty adjustment . I had to research the internet to find this out. When I took my truck back to the original dealer, they blamed me for not knowing the language. …”

   NHTSA complaint #10679831, filed 2015-01, 110,000 miles

   “The blower motor resistor overheated and melted the wiring harness,almost caused a fire,burnt my fingers trying to stop it from starting to burn,my 7 year old was with me.”

   NHTSA complaint #10349804, filed 2010-08, 60,000 miles
5. 5
   Transmission and drivetrain

   Clunking drivetrain and hard transmission shifts

   • 8 complaints (6%)
   • median 36,000 mi at 3.5 yrs old (7 state mileage, few)
   • 1 mention a crash, fire or injury
   • filed 2006–2017

   Owners describe a clunk from the drivetrain when the transmission shifts or when the throttle is applied, along with hard gear changes. Some reports point to the valve body inside the transmission, while others involve the transfer case encoder motor and selector switch on four-wheel-drive trucks, where the service 4WD light came on. Complaints say dealers or independent shops replaced parts, and in some cases the problem returned later. Reported from roughly 20,000 to 115,000 miles, with several failures noted in the 36,000-53,000 mile range.

   3 related service bulletins

   What to check: Drive at low speed through several upshifts and downshifts and listen for a clunk; on 4WD models, cycle the transfer case through its modes and confirm the 4WD light behaves.

   2 excerpts from owner complaints in NHTSA records

   “2006 sierra -75000miles clunking in drivetrain when trans. Shifts rearend clunks and jumps in and out when diff lock is needed chatter in steering column engine light comes on when down to 1/2 -3/4 tank (everytime) refuel it goes out dash lights for the radio buttons slowly going out dash lights on the slider for heater controls going out very poor mpg 12-13 on a good day! Sure would like to have all the recalls and bulletins taken care of! Note to myself!! Never purchase a Gmc again!”

   NHTSA complaint #10441041, filed 2011-12, 72,000 miles

   “The contact owns a 2006 Gmc SIERRA 1500. The contact stated that when driving at various speeds or sitting idle in park, the four wheel drive switch would intermittently activate and independently shift into low drive. The vehicle was inspected by a dealer who informed the contact that he would need to replace the module in the transfer case. The vehicle was not repaired. The VIN was unavailable. The failure mileage was approximately 36,000.”

   NHTSA complaint #10372645, filed 2010-12, 36,000 miles

Buying note. These trucks are old enough that corrosion and deferred maintenance matter more than mileage, so a pre-purchase inspection focused on brake lines, ABS behavior and the blower circuit is worth the cost. Records showing brake line replacement and transmission or transfer case service would be a plus.

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.