As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AUTOTHROTTLE DISENGAGED ATTEMPTED TO RE-ENGAGE AND AGAIN DISENGAGED. NOTED THE #2 THRUST LEVER ADVANCED AND #1 MAINTAINED COMMANED N1 SETTING. GROUNDED - YES. IAW B737-900 AMM 22-11-00-740-801 - DFCS OPS TEST ACCOMPLISHED. NO FAULTS SEEN. IAW AMM TASK 22-31-TASK 804. NO FAULTS SEEN. AIRCRAFT CONSIDERED SERVICEABLE.