As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PERFORMING T/C 78273000, FOUND #2 ENG LONG TIME FAULT 73-10812, T12 SIGNAL IS OUT OF RANGE. GROUNDED - YES. FOUND FAULT ON EVERY FLIGHT LEG. REPLACED T12 SENSOR REF B737-800 AMM 73-21-05/401. EEC TEST PASSED WITH NO FAULTS FOUND. ETOPS GROUND VERIFICATION SUCCESSFUL.