As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON LINE-UP FOR TAKE-OFF, BEFORE POWER APPLIED, MASTER CAUTION-ENGINE CONTROL LIGHT NR 2 IN ALT AND LIGHT DID NOT EXTINGUISH. GROUNDED-YES. RAN B737-800 FIM TASK 73-00 TASK 801 EEC BITE SHOWS FAULTS 75-10582 AND 75-30532. RAN AFT TEST B737-800 AMM TASK 71-00-00-200-807-F00 TEST 12 ACTUATOR TEST SHOWN FAULT 75-30532. REMOVED AND REPLACED NR 2 ENGINE HMU REF T/C NR N8473000 AND N8473001. NO LEAKS OR FAULTS NOTED AFTER TESTS 3A,12 AND 13.