As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PHX - CREW REPORTED THAT "DURING CLIMB, WHEN CENTER AUTOPILOT SELECTED TO CMD, PITCH INCREASES APPROX 5 DEG AND AIRSPEED DECREASES 20-30 KNOTS BELOW SELECTED ORANGE BUG SPEED. LEFT AND RIGHT AUTO PILOTS FUNCTION NORMALLY". MAINTENANCE REMOVED AND REPLACED THE CENTER IRU, OPS CHECK WAS GOOD.