Two problems related to check engine light on have been reported for the 2020 GMC Sierra 1500. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2020 GMC Sierra 1500 based on all problems reported for the 2020 Sierra 1500.
My 2020 5. 3 l GMC at4 is experiencing loss of power with bucking & stalling. Cylinders are not activating when called check engine light is flashing, it starts rough and makes numerous noises at various speeds, as well as at idle. So I brought my vehicle to my local auto repair shop. Our mechanic found two failed fuel injectors and a failed throttle body. Then the loud knocks in my block failed an acoustic test. He also determined the lifters, push rods and camshaft are experiencing excessive wear. The afm system has failed! he warned me that further use of my motor (with only 42k miles on it) will cause a catastrophic failure. My research shows that these issues are becoming common of 5. 3 GMC motors. We searched the country for a rebuilt motor and found that none are available for the next several months. However, I was able to find a new motor at much greater cost. GMC has declined assistance at this time. My vehicle has no value as is, so I ordered the new gm engine. Without the dod system, these engines were designed to go well over 100,000 miles. I am a faithful GMC owner and none of my previous GMC trucks (2003, 2013, 2015, 2019) had such a major problem. Now the 2020's fuel saving system has failed and requires repairs that amount to half the value of my truck. When a full size truck stalls on the highway it's certainly life threatening.
~tl-the contact owns a 2020 GMC Sierra 1500. The contact stated that intermittent the vehicle would not start. The contact also stated that the vehicle failed to start rondonwnly. The contact stated when he start the vehicle using the key fob, the vehicle failed to start but when he attempted a second time using the key fob the vehicle started. The contact stated that the first time when the failure occurred when he try the push button to start the vehicle the vehicle failed to start but with a second attempt after hours with the push button the vehicle started. The contact stated that the failure occurred twiced. The contact stated that the check engine warning light illuminated the first time when the failure first occurred. The contact stated that on his way to the dealer the check engine warning light unilluminated. The vehicle was taken to mckenzie Buick-GMC, 6500 caroline st, milton, FL 32570, and was diagnosed but was not able to find a failure code. However, the failure recurred the contact called the same dealer and informed them of the failure. The vehicle was not yet taken to a dealer. The manufacturer was not made aware of the failure. The failure mileage was approximately 86. Aw.