As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LT ENGINE START ABORTED DUE TO A CAUTION MESSAGE ON START. RETURNED TO THE GATE, MAINTENANCE COMPLIED WITH TROUBLESHOOTING PROCEDURES, SWAPPED STARTER CONTROL VALVES BETWEEN THE 2 ENGINES. COULD NOT DUPLICATE ANY PROBLEMS. PUT VALVE BACK ON PROPER ENGINES. OPERATIONAL CHECKS GOOD. AIRCRAFT RETURNED TO SERVICE. NO PARTS REPLACED.