As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHILE PERFORMING TASK CARD 78273000, FOUND FAULT 73-10312 "THE START SWITCH SIGNAL AND ARINC BUS DATA DISAGREE" ON ENGINE 2. GROUNDED - YES. PERFORMED START SWITCH SIGNAL AND ARINC BUS DATA DISAGREE IAW B737-800 FIM 73-24 TASK 813. FOUND START SWITCH INOP. REMOVED AND REPLACED START SWITCH IAW AMM 80-11-00. OPS CHECK GOOD. NO DEFECTS NOTED AT THIS TIME.