As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON CLIMBOUT AUTOPILOT B WAS SELECTED AFTER A COUPLE OF SECONDS IT DIS-ENGAGED. CONSULTED QRH AND AUTOPILOT B WAS SELECTED AGAIN AND IT DIS-ENGAGED AFTER A COUPLE OF SECONDS. AUTOPILOT A WAS SELECTED AND IT WORKED NORMAL. GROUNDED - YES. REMOVED & REPLACE BOTH SOLENOIDS AT A/P ACTUATOR A (M943). IAW B737-900 AMM 22-11-12-400-801.