As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW REPORTED THAT SHORTLY AFTER TAKEOFF WHEN TRANSFERRING BLEED AIR FROM THE APU TO THE ENGINE BLEEDS RECEIVING A RT AND LT PACK HIGH PRESSURE MESSAGE. THE CREW DECLARED AN EMERGENCY. RAN THE QRH AND THE MESSAGE DID NOT DISAPPEAR. TRANSFERRED THE BLEEDS BACK TO THE APU THE MESSAGE WENT AWAY. CANCELED THE EMERGENCY AND RETURNED TO DEPARTURE AS A PRECAUTION. PERFORMED ENGINE RUNS, OPS CHECKED GOOD.