As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ADP PRESSURE LIGHT AND DEMAND PUMP EICAS MESSAGE DISPLAYED WITH DEMAND PUMP SW IN ON POSITION DURING TAXI, AIRCRAFT RETURNED TO BLOCK AND WAS GROUNDED BY MAINTENANCE. MAINTENANCE TROUBLESHOT ADP IN B767 FIM 29-11 FAULT TREE 814 TO A BAD ADP PRESSURE SWITCH, #32 ON THE FAULT TREE. ADP WAS PLACED ON MEL IAW MEL 29-11-3. AIRCRAFT WAS RETURNED TO SERVICE.