Xerox 2135DX - Phaser Color Laser Printer Service Manual page 86

The following messages are showing at warm-up and during printing.
: Number of sheets printed for test (in units of sheets)
P
: Upper fuser heater temperature measurement (in degrees Celsius)
U
: Lower fuser heater temperature measurement (in degrees Celsius)
L
: Environmental temperature measurement (in degrees Celsius)
T
: Environmental humidity measurement (in units of%). The key
H
Value (3) changes the display.
7.
Press Enter (4) to end the test.
Service Guide 73