C0040 is a chassis trouble code that occurs in the GMC Sierra. GM designated C0040 to indicate an issue with the right front wheel speed sensor. Replacing your Sierra’s right front wheel speed sensor is the most common repair for C0040, but it’s not the only one. Wiring harness issues are common with this code. … Read more
C0035 is a manufacturer-specific chassis trouble code that can occur in the GMC Sierra. GM designated C0035 to indicate an issue with the left front wheel speed sensor. Replacing your Sierra’s left front wheel speed sensor is the most common fix for C0035, but it’s not the only one. C0035 Definition C0035: Left Front Wheel … Read more
P0523 is a standard OBD2 trouble code that can occur in the GMC Sierra. In layman’s terms, it indicates the signal from the oil pressure sensor is higher than its normal operating range (in terms of voltage). P0523 is generic (it has the same definition for all vehicles), repair steps will depend on your Sierra’s … Read more
P0705 is a very common transmission-related trouble code that can occur in the GMC Sierra. In layman’s terms, it means that your Sierra can’t tell what gear you’ve selected, which can have some real consequences on how it drives. It’s most likely caused by a bad Transmission Range Sensor (TRS), but there are other causes … Read more
P015D is a generic trouble code, which means that it has the same definition for the GMC Sierra as it would any other vehicle. The code indicates that the Oxygen (O2) sensor on bank 2 is not cycling from lean to rich as fast as it should be. P015D is usually caused by a bad … Read more
P015B is a generic trouble code, which means it has the same meaning any vehicle. In the case of the GMC Sierra, It indicates that the Oxygen (O2) sensor on bank 1 is not cycling from lean to rich as fast as it should be. P015B is usually caused by a bad oxygen sensor, but … Read more
Daytime running lights (or DRL) are specialized lights that come on when your GMC Sierra’s regular headlights are turned off. Their purpose is to make it easier for other drivers to see you, theoretically decreasing the odds of getting into an accident. If your Sierra’s DRL warning light is on, the powertrain control module (commonly … Read more
P2271 is a generic DTC trouble code that can affect the GMC Sierra. It indicates that the oxygen sensor located on bank 1 in the second position is continuously sending voltage with a value that is too rich. There are oxygen sensors on both sides of the catalytic converter. The “upstream” one is used for … Read more
P2279 is a generic OBD-II code. It indicates there is a vacuum leak coming from your GMC Sierra’s air intake system. While P2279 is a generic code (it has the same definition for the Sierra as it would any other vehicle made after 1996), repair steps will vary based on model year and engine. The … Read more
P0605 is a relatively rare OBD-II trouble code that can occur in the GMC Sierra. It indicates that PCM (powertrain control module) is not passing its ROM (read-only memory) self-test when you turn the ignition on. While P0605 is a generic code (it has the same meaning for any car or truck), it is most … Read more