C-2000 SL 737-SL-49-082 VERSION 5- APU ECU OPERATION SOFTWARE. SERVICE LETTER RECOMMENDED MOS Id-MAY-2010 SL 737-SL-49-084 HYDRAULIC LOCK IN APU SOLENOID VALVE. SERVICE LETTER RECOMMENDED MOS 06-APR-2012 SL 737-SL-49-085 LOW DUCT PRESSURE DUE TO APU INLET GUIDE VANE DISAGREES WITH COMMAND FAULT, SERVIC