P0000 is a rare OBD2 fault code that can affect the GMC Sierra. While there are over 10,000 DTC “P” codes, this is the only one reserved for “no fault detected” in your truck’s ECU (engine control unit) memory. It tells the scanner accessing the ECU that no codes are …
Read More »GMC Sierra Humming Noise Getting Louder With Speed: How to Fix
If your GMC Sierra has a humming noise at high speed, it can be distracting and, depending on the cause, dangerous. We’ve outlined the most common reasons why a humming noise in your truck gets louder with speed. We’ve also provided an audio sample of each issue to help determine …
Read More »GMC Sierra P0324: Meaning, Causes, + Likely Fix
P0324 is a common OBD2 trouble code. It indicates that there is an issue with your GMC Sierra’s knock control system. While P0324 is a generic code, repair steps will vary depending on your Sierra’s engine type and model year. However, some basic steps can be followed to help diagnose …
Read More »GMC Sierra P0678 Code: Cylinder 8 – Glow Plug Circuit
P0678 is a common diagnostic trouble code found in diesel engines. It’s a generic code, which means it has the same meaning for the GMC Sierra as it would any other vehicle made for the 1996 model year+. P0678 indicates that the eighth cylinder glow plug is not heating its …
Read More »GMC Sierra P0725 Code: Meaning, Causes, + Diagnosis
P0725 is a common OBD2 code that can occur in the GMC Sierra. It indicates an issue with the engine speed sensor input circuit (which measures the engine speed at the input shaft and helps the PCM determine when and how hard to shift the transmission). It’s a generic code, …
Read More »GMC Sierra C0040: Meaning, Causes, + Likely Fix
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 …
Read More »GMC Sierra C0035: Causes, Diagnosis, + Likely Fix
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 …
Read More »GMC Sierra P0523: Meaning, Causes, + Likely Fixes
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 …
Read More »GMC Sierra P0705: Meaning, Causes, & Diagnosis
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), …
Read More »GMC Sierra P015B: Meaning, Causes, & Diagnosis
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 …
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