GMC Terrain engine power reduced and check engine light on on GMC Terrain

Some GMC Terrain owners report experiencing the "Engine Power Reduced" message along with the "Check Engine" light, indicating that the engine control unit (ECU) has detected a malfunction and reduced engine power to prevent further damage. This issue can stem from a variety of common causes, such as a faulty throttle actuator control, charge air pipe malfunction, or malfunctioning sensors that lead to inaccurate readings. Owners have noted that this warning signifies their engine is not operating at full capacity due to problems in critical components like the throttle, fuel, emissions, or other vital systems. Additionally, issues with the throttle body can prevent the ECU from receiving proper voltage responses for acceleration, leading to an unresponsive throttle that complicates acceleration or maintaining speed. It is recommended that owners experiencing these warnings have their GMC Terrain inspected by a qualified mechanic to identify and resolve the specific cause of the issue.