As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PILOT REPORTED THAT AT 1700 RPM INSTRUMENT AIR PRESSURE (3.5 HG) UPON TROUBLESHOOTING OF THE INSTRUMENT AIR PRESSURE SYSTEM TECHNICIAN FOUND AIR PUMP WAS NOT PRODUCING ENOUGH PRESSURE. PROBABLE CAUSE IS UNKNOWN AT THIS TIME. NO RECOMMENDATION AT THIS TIME EITHER. (K)