2014 - 2016 Corvette: Service Bulletin: Surge Misfire Feeling Sensation During Highway Steady State Driving - (Jun 6, 2016)

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

Condition/Concern

    A concern of surge misfire feeling sensation during highway steady state driving in manual mode or automatic, typically 6th, 7th, 8th gear accelerating 1000 to 2500 rpm under load. TCC engaged, no misfire data or P0300 codes present.

Recommendation/Instructions

    This is operating as Designed. TCC slip with condition present, with scan tool technician may monitor plus or minus about 6-0 rpm at the most, usually lower. This occurs about 30 to 60% throttle. This is normal condition (fish bite / chuggle) with the TCC locked.

    The normal operation of engines and transmissions generate various vibrations and engine and transmission mounts try to isolate those vibrations from the rest of the vehicle.  While the mounts do a great job of isolating most vibrations there may still be certain engine loads and rpm’s that generate vibrations that customers may feel in the vehicle.  Changes in engine load or rpm will change the vibrations produced making it more or less apparent to occupants in the vehicle. When issues of this nature are encountered, like equipped vehicles should be compared, and if consistent results are identified, this should be considered a “normal” characteristic of the vehicle.

    Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.