Q: Car jerk when at 1 RPM while stopping

If the engine RPM doesn’t change during this jerk, or "transition", it is more likely that the cause is rough or abrupt downshifting. Engine RPM can be logged using a scan tool and your car may be new enough that the gear position can be viewed on the scan tool, too, obviously with the idea of determining if the jerk coincides with a downshift. If the transmission is ruled out, and there is an RPM "excursion", the cause of that will be found in components such as the idle air control valve, MAF sensor, TPS (throttle position sensor) and so forth. They key is to view the output of these sensors as the engine operates. They must be operating, that is output data, within specified ranges. If you desire a speedy resolution to this, the recommended service to request is an engine diagnostic. If you request that service, the responding certified mechanic will get this diagnosed and resolved, right at your location. If you have further questions or concerns, do not hesitate to re-contact YourMechanic because we want you to make the most of your repair dollars and help you to get the best possible results.