User Manual

TIC LEXION 500 Electric System
03/05 Lex-e-44a 44a-3
Description of function:
Electro-hydraulic gearshift As a pre-condition for carrying out an electro-hydraulic drive range changeover,
the signals of the actual value switch Z57 (ground speed control lever in neutral
position), Z79 and Z80 (actuation of both service brakes) must be identified by the
electro-hydraulic gearshift (EHS) module A37.
Module A37 (EHS) controls the solenoid coils Y107, Y108 and Y123 of the gear
preselection correspondingly via switches S70 and S71.
The master valve (Y77) is also actuated via the diode PCB (DO) in parallel with
the solenoid coils by module A37 (EHS) because these functions require that
pressure is built up in the system.
The realization of the drive range changeover is controlled by module A37 (EHS)
via the actual value switches Z82, Z83, Z95, Z97 and Z96.
Module A37 (EHS) performs several gearshift processes under program control
for changing over the drive range if necessary if the changeover process is
hindered by external influences on the gearshift.
If the selected gear cannot be engaged within 1 second, another attempt is made
for engaging other gears.
An error message in terminal (A30) appears when the gear cannot be engaged
within 4 seconds.
At the same time, the gearbox neutral signal light H63 flashes.
The gear engaged is indicated by the signal lights H60, H61, H62 and H63.
Supply voltage of
gearshift actual value
switches
The supply voltage of the gearshift actual value switches from pin 8 of module
A37 (EHS) is 12 volt and is limited to a current consumption of 200 mA max.
Important! Suitable measuring devices must be used for error diagnosis.
Diagnosis Errors occurred during the gearshift process are displayed as messages on
terminal A30.
Gearshift logic EHS
3-speed:
1
st
gear
engaged
2
nd
gear
engaged
3
rd
gear
engaged
2
nd
and 3
rd
gear neutral
position
1
st
gear
neutral
position
Designation
Z82 Z83 Z95 Z97 Z96
Switch type NO
contact
NO
contact
Changeover
contact
NO contact NO contact
Module A37 Pin 11 Pin 12 Pin 13 Pin 10 Pin 17
1
st
gear
12 V
(200 mA)
0 V 0 V 12 V
(200 mA)
0 V
2
nd
gear
0 V 12 V
(200 mA)
0 V 0 V 12 V
(200 mA)
3
rd
gear
0 V 0 V 12 V
(200 mA)
0 V 12 V
(200 mA)
Neutral
0 V 0 V 0 V 12 V
(200 mA)
12 V
(200 mA)