Sensors
Table 1-5 Sensors
Component abbreviation Component name
SR1 Drum home position sensor 1
SR2 Drum home position sensor 2
SR3 Drum home position sensor 3
SR5 Fuser output sensor
SR6 Output bin full sensor
SR7 Fuser pressure release sensor
SR8 Registration sensor
SR9 Fuser pressure release sensor
SR11 Developer alienation sensor
SR13 Tray 2 cassette sensor
SR14 Fuser loop 1 sensor
SR15 Fuser loop 2 sensor
SR17 ITB alienation sensor
SR20 Tray 2 paper sensor
SR21 Tray 1 paper sensor
SR22 Duplexer refeed sensor (HP LaserJet Enterprise 500 color M551dn and HP LaserJet Enterprise
500 color M551xh only)
OHT sensor (in)
OHT sensor (out)
RD sensor (front)
RD sensor (rear)
Environmental sensor (temperature and humidity)
Yellow toner-level sensor
Magenta toner-level sensor
Cyan toner-level sensor
Black toner-level sensor
Toner collection-box-full sensor
Motors and fans
ENWW
Engine control system
7