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| Illustration 1 | g01046249 |
Actual gear indicator circuit | |
The components of the actual gear indicator circuit are the Power Train Electronic Control Module (Power Train ECM), the Caterpillar Monitoring System ECM, the speedometer/tachometer module, the autoshift control switch (STIC steering), the transmission control (STIC steering), and the transmission solenoids.
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| Illustration 2 | g00988862 |
Cab (1) Power Train ECM | |
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| Illustration 3 | g00988863 |
Cab (2) Caterpillar Monitoring System ECM (behind display) | |
With the key start switch in the ON position, 24 volt power is supplied from the batteries via circuit breaker #9 to the Power Train ECM and via circuit breaker #1 to the Caterpillar Monitoring System ECM and to the speedometer/tachometer module.
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| Illustration 4 | g00988864 |
Cab (3) Speedometer/tachometer module (4) Actual gear indicator | |
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| Illustration 5 | g01046253 |
Dash panel (5) Autoshift control switch (STIC steering) (6) MANUAL position (7) AUTOMATIC position | |
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| Illustration 6 | g01046254 |
Cab (8) Transmission control (STIC steering) (9) Upshift switch (10) Downshift switch (11) Transmission direction control switch | |
When autoshift control switch (STIC steering) (5) is in MANUAL position (6), Power Train ECM (1) receives a signal from transmission direction control switch (11) for the direction that is currently selected. Upshift switch (9) and downshift switch (10) determine the gears that are currently selected. The signal is sent to Caterpillar Monitoring System ECM (2) via the CAT Data Link and then the is sent to speedometer/tachometer module (3). The speedometer/tachometer module will display the actual gear in the display window. Actual gear indicator (4) displays the gear that is currently selected by the Power Train ECM. The Power Train ECM will energize transmission solenoids as required.
When the autoshift control switch (STIC steering) is in AUTOMATIC position (7), the Power Train ECM receives a signal from the transmission direction control switch for the direction that is currently selected. The Power Train ECM will change gears within the transmission automatically. The gear that is currently selected in the AUTOMATIC position, will be displayed on the actual gear indicator.
Reference: For more information on the actual gear indicator system refer to Systems Operation, Testing and Adjusting, "Caterpillar Monitoring System" for the machine that is being serviced.