As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON CLIMB OUT, ACTUATED DEICE BOOTS. PNEUMATIC GAUGE FLUCTUATED BETWEEN 18-20 PSI PLUS. AFTER CYCLING BLEED AIR VALVES TO OFF PNEUMATIC GAUGE STABILIZED AT 20 PSI. TURNING THE SYSTEM ON RESULTED IN PNEUMATIC GAUGE FLUCTUATING. AIRCRAFT DIVERTED TO TEB. MAINTENANCE REPLACED THE PRESSURE REGULATOR MANIFOLD VALVE. SYSTEM OPERATIONAL CHECKS WERE ACCOMPLISHED. AIRCRAFT WAS RETURNED TO SERVICE.