As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
IAH - DURING TAXI THE CREW REPORTED SMOKE IN THE COCKPIT AND CABIN PRIOR TO DE-ICE WITH THE NUMBER ONE ENGINE RUNNING. THE AIRCRAFT RETURNED TO THE GATE WITHOUT INCIDENT. IAH MAINTENANCE REMOVED AND REPLACED THE NUMBER ONE ENGINE, OPERATIONALLY TESTED WITH NO DEFECTS, AND THE AIRCRAFT WAS APPROVED FOR RETURN TO SERVICE.