This Preliminary Information communication provides information to the technician about vehicles that have a lack of power on initial acceleration from a stop when the ambient temperature is approximately 103F or greater. Technician should follow published Service Information diagnosis if the concern is present. If published Service Information diagnostics does not isolate the cause of this lack of power concern, take the Tech 2 scan tool and take a snapshot of the concern happening and note the spark parameter in the ignition data list. If it drops near/below 0 degrees during the concern, technician will need to contact General Motors Technical Assistance Center for further assistance.
