2011 GMC Sierra 1500

Problems, recalls and owner-reported issues

Air bags is the leading concern among 366 owner complaints filed for this model year. This is the 9th highest complaint count among 26 Sierra 1500 model years with reports.

Complaints by model year
  1. 366

Of the 2011 reports, 6 involved a crash and 3 involved a fire. 12 people were injured.

Primary concernAir bags138 reports · 38% of complaints
Owner complaints366Filed with NHTSA
Recall relationship5 safety recallsNHTSA campaign records

What owners report most often

  1. Air bags138
  2. Other or unspecified108
  3. Structure62
  4. Power train32
  5. Engine23
  6. Electrical system20
  7. Electronic stability control (ESC)11
  8. Fuel/propulsion system11

Recalls and investigations

  1. Air bags, frontal, passenger side, inflator moduleFeb 5, 2021

    General Motors, LLC (GM) is recalling certain 2014 Cadillac Escalade, Escalade ESV, Chevrolet Silverado 2500, Silverado 3500, Suburban, Tahoe, GMC Sierra 2500, Sierra 3500, Yukon, and Yukon XL vehicles originally sold, or ever registered, in the states of AL, CA, FL, GA, HI, LA, MS, SC, TX, PR, AS, GU, the MP, and VI or "Zone A." Additionally GM is recalling certain 2011-2014 Cadillac Escalade, Escalade ESV, Chevrolet Silverado 2500, Silverado 3500, Suburban, Tahoe, GMC Sierra 2500, Sierra 3500, Yukon, Yukon XL and 2011-2013 Cadillac Escalade EXT, Chevrolet Avalanche, Silverado 1500, and GMC Sierra 1500 vehicles originally sold, or ever registered, in the states of AZ, AR, DE, DC, IL, IN, KS, KY, MD, MO, NE, NV, NJ, NM, NC, OH, OK, PA, TN, VA, and WV or "Zone B." Additionally, GM is recalling certain 2010-2014 Cadillac Escalade, Escalade ESV, Chevrolet Silverado 2500, Silverado 3500, Suburban, Tahoe, GMC Sierra 2500, Sierra 3500, Yukon, and Yukon XL and 2010-2013 Cadillac Escalade EXT, Chevrolet Avalanche, Silverado 1500, and GMC Sierra 1500 vehicles originally sold, or ever registered, in the states of AK, CO, CT, ID, IA, ME, MA, MI, MN, MT, NH, NY, ND, OR, RI, SD, UT, VT, WA, WI, and WY or "Zone C." These vehicles are equipped with non-desiccated passenger frontal inflators containing phase-stabilized ammonium nitrate (PSAN) propellant. These inflators may explode due to propellant degradation occurring after long-term exposure to high absolute humidity, high temperatures, and high temperature cycling.

    An inflator explosion may result in sharp metal fragments striking the driver or other occupants, resulting in serious injury or death.

    GM will notify owners, and dealers will replace the front passenger air bag inflator with an alternate one, free of charge. Interim letters notifying owners of the safety risk were mailed on February 25, 2021. Second notification letters will be mailed once the remedy is available. Owner notification letters were mailed to 40 VIN owners on May 11, 2021. A second owner notification letter was mailed to all other owners on January 24, 2022. Owners may contact Chevrolet customer service at 1-800-222-1020; Cadillac customer service at 1-800-458-8006; and GMC customer service at 1-800-462-8782. GM's number for this recall is N212328800.

    Campaign 21V054000 on NHTSA.gov

  2. Air bags, frontal, passenger side, inflator moduleFeb 5, 2021

    General Motors, LLC (GM) is recalling certain 2007-2011 Cadillac Escalade, Escalade ESV, Escalade EXT, Chevrolet Avalanche, Silverado 1500, Suburban, Tahoe, GMC Sierra 1500, Yukon, Yukon XL, and 2009-2011 Chevrolet Silverado 2500, Silverado 3500, GMC Sierra 2500 and Sierra 3500 vehicles originally sold, or ever registered, in the states of Alabama, California, Florida, Georgia, Hawaii, Louisiana, Mississippi, South Carolina, Texas, Puerto Rico, American Samoa, Guam, the Northern Mariana Islands (Saipan), and the U.S. Virgin Islands or "Zone A." Additionally, GM is recalling certain 2007-2008 Cadillac Escalade, Escalade ESV, Escalade EXT, Chevrolet Avalanche, Silverado 1500, Suburban, Tahoe, GMC Sierra 1500, Yukon, Yukon XL vehicles originally sold, or ever registered, in the states of Arizona, Arkansas, Delaware, District of Columbia, Illinois, Indiana, Kansas, Kentucky, Maryland, Missouri, Nebraska, Nevada, New Jersey, New Mexico, North Carolina, Ohio, Oklahoma, Pennsylvania, Tennessee, Virginia, and West Virginia or "Zone B." These vehicles are equipped with non-desiccated passenger frontal inflators containing phase-stabilized ammonium nitrate (PSAN) propellant. These inflators may explode due to propellant degradation occurring after long-term exposure to high absolute humidity, high temperatures, and high temperature cycling.

    An inflator explosion may result in sharp metal fragments striking the driver or other occupants, resulting in serious injury or death.

    GM will notify owners, and dealers will replace the front passenger air bag inflator with an alternate one, free of charge. Interim letters notifying owners of the safety risk were mailed on February 22, 2021. Second notification letters will be mailed once the remedy is available. Owner notification letters were mailed on March 1, 2021. Owners may contact Chevrolet customer service at 1-800-222-1020; Cadillac customer service at 1-800-458-8006; and GMC customer service at 1-800-462-8782. GM's number for this recall is N212328760.

    Campaign 21V050000 on NHTSA.gov

  3. EquipmentApr 26, 2018

    General Motors LLC (GM) is recalling certain 2009-2014 Chevrolet Silverado HD and GMC Sierra HD, 2009 GMC Topkick 5000, 6000, 7000 and 8000 Series and Isuzu F Series, and 2009-2018 Chevrolet Express, and GMC Savana vehicles, equipped with certain Plastic-Handle Fire Extinguishers or Push Button 'Pindicator' Fire Extinguishers. These extinguishers may become clogged, preventing the extinguisher from discharging as expected or requiring excessive force to activate the extinguisher. Additionally, in certain models, the nozzle may detach from the valve assembly with enough force that it could cause injury and also render the product inoperable. For a full list of the affected fire extinguisher models visit: https://static.nhtsa.gov/odi/rcl/2017/RMISC-17E062-5427.pdf

    In the event of a fire, if the fire extinguisher does not function properly, it can increase the risk of injury.

    GM will notify owners, instructing them to contact Kidde to get a replacement fire extinguisher, free of charge. The recall began June 11, 2018. Owners may contact Chevrolet customer service at 1-800-222-1020, GMC customer service at 1-800-462-8782, and Isuzu customer service at 1-866-441-9638. GM's number for this recall is 18146.

    Campaign 18V267000 on NHTSA.gov

  4. Suspension, rear, axle, spindleJan 6, 2011

    GENERAL MOTORS IS RECALLING CERTAIN MODEL YEAR 2011 CADILLAC ESCALADE, ESCALADE ESV, ESCALADE EXT; CHEVROLET AVALANCHE, COLORADO, EXPRESS, SILVERADO, SUBURBAN, TAHOE; AND GMC CANYON, SIERRA, SAVANA, YUKON AND YUKON XL VEHICLES. THE REAR AXLE CROSS PINS WERE NOT PROPERLY HEAT TREATED AND COULD FRACTURE AND BECOME DISPLACED WITHIN THE REAR AXLE. SHOULD THE PIN SHIFT OUT OF POSITION, IT COULD CREATE AN INTERFERENCE CONDITION AND CAUSE THE REAR AXLE TO LOCK.

    THE DRIVER MAY NOT BE ABLE TO MAINTAIN DIRECTIONAL CONTROL OF THE VEHICLE AND A CRASH COULD OCCUR WITHOUT WARNING.

    DEALERS WILL INSTALL A NEW REAR AXLE CROSS PIN FREE OF CHARGE. THE SAFETY RECALL BEGAN ON JANUARY 11, 2011. OWNERS MAY CONTACT CADILLAC AT 1-866-982-2339, CHEVROLET AT 1-800-630-2438, GMC AT 1-866-996-9463 AND AT THE OWNER CENTER AT WWW.GMOWNERCENTER.COM.

    Campaign 11V007000 on NHTSA.gov

  5. Suspension, rear, axle, spindleDec 17, 2010

    GENERAL MOTORS IS RECALLING CERTAIN MODEL YEAR 2011 CADILLAC ESCALADE EXT, CHEVROLET AVALANCHE, SILVERADO LD AND GMC SIERRA LD VEHICLES. THE REAR AXLE CROSS PINS WERE NOT PROPERLY HEAT TREATED AND COULD FRACTURE AND BECOME DISPLACED WITHIN THE REAR AXLE. SHOULD THE PIN SHIFT OUT OF POSITION, IT COULD CREATE AN INTERFERENCE CONDITION AND CAUSE THE REAR AXLE TO LOCK.

    THE DRIVER MAY NOT BE ABLE TO MAINTAIN DIRECTIONAL CONTROL OF THE VEHICLE AND A CRASH COULD OCCUR WITHOUT WARNING.

    DEALERS WILL INSTALL A NEW REAR AXLE CROSS PIN FREE OF CHARGE. THE SAFETY RECALL BEGAN ON JANUARY 11, 2011. OWNERS MAY CONTACT CADILLAC AT 1-866-982-2339, CHEVROLET AT 1-800-630-2438, GMC AT 1-866-996-9463 AND AT THE OWNER CENTER AT WWW.GMOWNERCENTER.COM.

    Campaign 10V643000 on NHTSA.gov

Representative owner complaints

366 reports, newest first.

  1. Air bags, Oct 31, 2017

    TAKATA RECALL I CALLED THE DEALER(AUTONATION/CORPUS CHRISTI) AFTER MAKING 5 CALLS(ON THREE DIFFERENT DAYS) AND LEAVING MESSAGES WITH NO CALL BACK I FINALLY SPOKE WITH JACKIE WHO INFORMED ME THAT GMC DOES NOT HAVE A REPLACEMENT PART AND COULD NOT PROVIDE ME WITH ANY INFORMATION AS TO WHEN THE PART WOULD BECOME AVAILABLE.

  2. Air bags, Oct 30, 2017

    TL* THE CONTACT OWNS A 2011 GMC SIERRA 1500. THE CONTACT RECEIVED NOTIFICATION OF NHTSA CAMPAIGN NUMBER: 16V381000 (AIR BAGS). THE PARTS TO DO THE REPAIR WERE UNAVAILABLE. THE CONTACT STATED THAT THE MANUFACTURER EXCEEDED A REASONABLE AMOUNT OF TIME FOR THE RECALL REPAIR. BELL AND BELL BUICK GMC TRUCKS (2491 HWY 9 E, LITTLE RIVER, SC) WAS CONTACTED AND CONFIRMED THAT THE PARTS WERE NOT AVAILABLE FOR THE RECALL REMEDY. THE MANUFACTURER WAS MADE AWARE OF THE ISSUE AND WAS NOT ABLE TO CONFIRM WHEN THE PARTS WERE TO BECOME AVAILABLE. THE CONTACT HAD NOT EXPERIENCED A FAILURE. VIN TOOL CONFIRMS PARTS NOT AVAILABLE. *BF UPDATED 8/21/18*JB

  3. Air bags, Oct 26, 2017

    TL* TAKATA RECALL. THE CONTACT OWNS A 2011 GMC SIERRA 1500. THE CONTACT RECEIVED NOTIFICATION OF NHTSA CAMPAIGN NUMBER: 15V381000 (AIR BAGS). THE PART TO DO THE REPAIR WAS UNAVAILABLE. THE CONTACT STATED THAT THE MANUFACTURER EXCEEDED A REASONABLE AMOUNT OF TIME FOR THE RECALL REPAIR. THE DEALER WAS CONTACTED (BECK AND MASTEN PONTIAC, GMC IN HOUSTON, TX, 281- 469-5222) AND CONFIRMED THAT THE PARTS WERE NOT AVAILABLE FOR THE RECALL REMEDY. THE MANUFACTURER WAS MADE AWARE OF THE ISSUE AND WAS NOT ABLE TO CONFIRM WHEN THE PARTS WERE TO BECOME AVAILABLE. THE CONTACT HAD NOT EXPERIENCED A FAILURE. VIN TOOL CONFIRMS PARTS NOT AVAILABLE.

  4. Air bags, Oct 26, 2017

    TL* TAKATA RECALL. THE CONTACT OWNS A 2011 GMC SIERRA 1500. THE CONTACT RECEIVED NOTIFICATION OF NHTSA CAMPAIGN NUMBER: 16V381000 (AIR BAGS); HOWEVER, THE PARTS TO DO THE REPAIR WERE UNAVAILABLE. THE CONTACT STATED THAT THE MANUFACTURER EXCEEDED A REASONABLE AMOUNT OF TIME FOR THE RECALL REPAIR. THE CONTACT CALLED GLYNN SMITH CHEVROLET BUICK GMC (600 COLUMBUS PKWY, OPELIKA, AL 36801 (334) 749-1454) WHERE IT WAS CONFIRMED THAT THE PARTS WERE NOT AVAILABLE FOR THE RECALL REMEDY. THE MANUFACTURER WAS NOT NOTIFIED. THE CONTACT HAD NOT EXPERIENCED A FAILURE. VIN TOOL CONFIRMS PARTS NOT AVAILABLE/PARTS DISTRIBUTION DISCONNECT.

  5. Air bags, Oct 26, 2017

    TAKATA RECALL I HAVE CALLED RON CARTER AUTOLAND/GMC REQUESTING THE AIRBAG COMPONENT FOR REPLACEMENT, BUT WAS TOLD THAT THERE ARE NO REPLACEMENT PARTS AVAILABLE AND HAVE BEEN NONE. I THEN ASKED WHEN REPLACEMENTS WOULD BE AVAILABLE AND WAS TOLD THERE WAS NO TIME TABLE FOR SUCH. I MENTIONED THAT THIS RECALL HAS BEEN GOING ON FOR YEARS WITH NOTHING BEING DONE AT THIS TIME. SHE TOLD ME SHE KNOWS AND UNDERSTANDS, BUT IT IS OUT OF HER HANDS.

  6. Electrical system, Air bags, Structure, Oct 26, 2017, crash

    TAKATA RECALL I GOT REAR ENEDED AT A STOP SIGN, COMPLETELY STOPPED AND THE LADY JUST SMASHED RIGHT INTO THE BACK OF ME. NO AIR BAGS EVER EVEN DEPLOYED!

  7. Air bags, Oct 21, 2017

    TAKATA RECALL - DEALERSHIP WILL NOT REPALCE AIR BAGS AFTER SEVERAL REQUESTS

  8. Air bags, Oct 21, 2017

    TAKATA RECALL- TAKATA HAS FAILED TO MEET THE AUGUST DEADLINE FOR RECALLING MY VEHICLE. IN THE MEAN TIME I AM DRIVING A VEHICLE THAT CAN CAUSE MYSELF, MY WIFE, AND MY CHILDREN TO POSSIBLE INJURY AND/OR DEATH.

  9. Air bags, Oct 19, 2017

    TL* TAKATA RECALL. THE CONTACT OWNS A 2011 GMC SIERRA 1500. THE CONTACT RECEIVED NOTIFICATION OF NHTSA CAMPAIGN NUMBER: 16V381000 (AIR BAGS); HOWEVER, THE PARTS TO DO THE REPAIR WERE UNAVAILABLE. THE CONTACT STATED THAT THE MANUFACTURER EXCEEDED A REASONABLE AMOUNT OF TIME FOR THE RECALL REPAIR. THE DEALER RICK MATTHEWS BUICK GMC (15164 CORTEZ BLVD, BROOKSVILLE, FL 34613) WAS CONTACTED AND CONFIRMED THAT THE PARTS WERE NOT AVAILABLE FOR THE RECALL REMEDY. THE MANUFACTURER WAS NOT CONTACTED. THE CONTACT HAD NOT EXPERIENCED A FAILURE. VIN TOOL CONFIRMS PARTS NOT AVAILABLE. *LN UPDATED 7/31/18*JB

  10. Structure, Other or unspecified, Oct 13, 2017

    ALL FOUR OF THE DOOR HANDLES ON MY TRUCK ARE BREAKING OFF; EVEN THOUGH GMC HAS KNOWLEDGE OF THE PROBLEM THEY REFUSE TO REPLACE THE DOOR HANDLES, BECAUSE MY TRUCK IS OUT OF WARRANTY. IT'S A WELL KNOWN PROBLEM, YOU CAN EVEN GOOGLE A SEARCH FOR THIS MATTER AND SEE OTHER CONSUMERS THAT HAVE THE SAME PROBLEM. IT'S A SAFETY PROBLEM, IF SOMEONE, IN NEED OF HELP, IS UNCONSCIOUS IN A VEHICLE WITH THE SAME BROKEN DOOR HANDLE PROBLEM, HOW WOULD THEY GET HELP FAST, IF THE DOOR HANDLES ARE BROKEN.

  11. Other or unspecified, Oct 2, 2017

    DASH BOARD IS CRACKING ABOVE INSTRUMENT PANEL ON TOP ABOUT THREE TO FIVE INCHES FROM BOTTOM OF FRONT WINDSHIELD JUST APPEARED ON 10/02/2017 . THIS CRACK WAS NOT THERE ON 10/01/2017, VEHICLE WAS STATIONARY WAS NOT DRIVEN AT ALL YESTERDAY.

  12. Air bags, Other or unspecified, Oct 1, 2017

    THE DASH CRACKED NEAR THE PASSENGER SIDE AIRBAG. THE DEALERSHIP SAID THEY KNOW ALL ABOUT THIS AND SAID IT IS SAFE TO DRIVE. FEARING PLASTIC PIECES FLYING IN THE EVENT OF AN AIRBAG DEPLOYMENT, I PAID TO HAVE THE DASH REPLACED. LATER, I DROVE INTO A POTHOLE AT A VERY LOW RATE OF SPEED. THE SECOND DASH CRACKED IN THE SAME SPOT. THE DEALER SAYS IT IS MY FAULT AND THAT THERE ARE NO SAFETY CONCERNS. GM IS AWARE OF THIS AND IS UNWILLING TO PAY FOR A NEW DASH. THEY ARE JEOPARDIZING THE LIVES OF MY PASSENGERS SO THAT THEY DO NOT LOSE PROFITS. THIS IS A RECURRING PROBLEM THAT SHOULD BE REPAIRED BY GM SO THAT LIVES ARE NOT UNNECESSARY LOST.

  13. Other or unspecified, Sep 27, 2017

    DASH IS CRACKED ABOVE INSTRUMENT CLUSTER AND ABOVE PASSENGER AIRBAG POSING A SAFETY CONCERN IN THE EVEN OF AIRBAG DEPLOYMENT.

  14. Air bags, Sep 8, 2017

    TL* TAKATA RECALL. THE CONTACT OWNS A 2011 GMC SIERRA 1500. THE CONTACT RECEIVED A RECALL NOTIFICATION FOR NHTSA CAMPAIGN NUMBER: 16V381000 (AIR BAGS). THE PART TO DO THE REPAIR WAS UNAVAILABLE. THE CONTACT STATED THAT THE MANUFACTURER EXCEEDED A REASONABLE AMOUNT OF TIME FOR THE RECALL REPAIR. THE DEALER WAS NOT CONTACTED. THE MANUFACTURER WAS NOTIFIED OF THE ISSUE AND CONFIRMED PARTS WERE NOT AVAILABLE. THE CONTACT HAD NOT EXPERIENCED A FAILURE. VIN TOOL CONFIRMS PARTS NOT AVAILABLE.

  15. Other or unspecified, Sep 5, 2017

    THE DASH BOARD IS CRACKING AROUND THE AIR BAG.

  16. Air bags, Aug 25, 2017

    TL* TAKATA RECALL. THE CONTACT OWNS A 2011 GMC SIERRA 1500. THE CONTACT RECEIVED NOTIFICATION OF NHTSA CAMPAIGN NUMBER: 16V381000 (AIR BAGS); HOWEVER, THE PARTS TO DO THE REPAIR WERE UNAVAILABLE. THE CONTACT STATED THAT THE MANUFACTURER EXCEEDED A REASONABLE AMOUNT OF TIME FOR THE RECALL REPAIR. THE DEALER (HENNESSY BUICK GMC, LOCATED AT 7261 JONESBORO RD, MORROW, GA 30260; (770) 729-4952) WAS CONTACTED AND CONFIRMED THAT THE PARTS WERE NOT AVAILABLE FOR THE RECALL REMEDY. THE MANUFACTURER WAS NOT CONTACTED. THE CONTACT HAD NOT EXPERIENCED A FAILURE. VIN TOOL CONFIRMS PARTS NOT AVAILABLE.

  17. Electrical system, Engine, Aug 21, 2017

    YESTERDAY AUGUST 20, 2017 IN THE LATE AFTERNOON WHILE DRIVING, MY 2011 GMC SIERRA DEAD STOPPED WITHOUT ANY NOTICE ALMOST CAUSING AN ACCIDENT . I REMAINED BLOCKING THE ROAD UNTIL THE POLICE ARRIVED TO PUSH MY VEHICLE TO THE SIDE OF THE ROAD. THE VEHICLE WAS UNABLE TO START EVEN WITH A JUMP. THE CAR IS NOW AT THE AUTO REPAIR SHOP AND THE AUTO MECHANIC STATED THAT THE HYBRID SYSTEM IS NOT RESPONDING.

  18. Other or unspecified, Aug 20, 2017

    DASH CRACKING AROUND AIR BAG AND AROUND DRIVER SIDE.IT SEEMS TO BE FALLING TO PIECES FOR NO APPARENT REASON

  19. Other or unspecified, Aug 15, 2017

    THE DASHBOARD HAS CRACKED, AS IT HAS DONE ON INNUMERABLE VEHICLES OF THIS AGE RANGE. I AM CONCERNED ABOUT THE SAFETY OF OCCUPANTS IF THE AIRBAGS DEPLOY.

  20. Wheels, Aug 2, 2017

    CHROME IS SEPARATING FROM ALLOY RIMS. RIMS ARE LEAKING AIR.

  21. Structure, Jul 26, 2017

    PURCHASED 2.5 MONTHS FROM LOCAL DEALERSHIP. SPOTLESS INTERIOR. PARKED TRUCK IN PARKING LOT FOR ABOUT AN HOUR FOR CHURCH AND NOTICED CRACK ABOVE PASSENGERS AIRBAG TO THE LEFT SPLITTING THE DASH COMPLETELY. ALSO BOWING TO DASH BRANCHING LEFT OF CRACK. WEATHER WAS AROUND 90 DEGREES AND I USE A SUNVISOR AND TYPICALLY CRACK MY WINDOWS. HAVE NOT CLEANED OR TOUCHED DASH IN THE TIME OF OWNERSHIP, OTHER THAN SLIDDING THE SUNVISOR TO WINDSHIELD. DEALERSHIP TODAY CLAIMED THEY CANNOT AND WILL NOT DO ANYTHING ABOUT IT UNTIL GMC ISSUES RECALL. AFTER RESEARCHING THIS IS APPARENTLY A COMMON COMPLAINT IN ALL GMC TRUCK MODELS FROM 07-13. CONCERNED WITH SAFETY OF AIRBAG PROJECTILING SHARDS OF DASH IF DEPLOYED.

  22. Other or unspecified, Jul 25, 2017

    DAHSBOARD IS CRACKING ALL OVER.

  23. Other or unspecified, Jul 21, 2017

    CRACKED DASHBOARD WITHOUT COLLISION OR ANY IMPACT. THE HEAT AND COLD CONTINUE TO CRACK THE DASH AND I AM CERTAIN THE ENTIRE DASH WILL EXPLODE IF ANY AIRBAG IS DEPLOYED OR COLLISION IS EXPERIENCED.

  24. Structure, Jul 19, 2017

    TL* THE CONTACT OWNS A 2011 GMC SIERRA 1500. THE CONTACT STATED THAT, OVER TIME, THE DASHBOARD BEGAN TO CRACK IN VARIOUS PLACES, BEGINNING ON THE UPPER DRIVER SIDE CORNER. THE VEHICLE WAS NOT TAKEN TO A DEALER OR INDEPENDENT MECHANIC. A DEALER WAS NOT CONTACTED. THE VEHICLE WAS NOT REPAIRED. THE MANUFACTURER WAS MADE AWARE OF THE FAILURE AND STATED THAT THEY WOULD NOT REPLACE THE DASHBOARD AS THERE WAS NO RECALL, BUT COULD POTENTIALLY PROVIDE SOME FINANCIAL ASSISTANCE. THE APPROXIMATE FAILURE MILEAGE WAS 85,000.

  25. Structure, Jul 18, 2017

    DASH CRACK ABOVE INSTRUMENT CLUSTER