GMC Envoy engine stalls when A/C or defrost is activated on GMC Envoy

Some GMC Envoy owners report experiencing engine stalling or shutdowns when activating the A/C or defrost, which may be attributed to several factors. These include fuel issues such as bad gas or water in the gas tank, which can lead to rough running conditions. Additionally, problems with the throttle body and idle air control (IAC) valve can result in stalling at idle, particularly if the IAC passageway is dirty or faulty. Some owners have also encountered issues with a seized A/C compressor, causing the serpentine belt to squeal and drag, leading to engine stalling when the A/C is engaged. Moreover, complications with the idle speed control air-bypass valve and related components can cause surges, stalls at stops, and slow idle speeds due to clogging from gunk and combustion residue. It is advisable for owners experiencing these issues to investigate these potential causes to ensure prompt resolution.