USING ON-BOARD DIAGNOSTICS
The Military 621G Scraper has three electronic control modules (ECMs): engine, transmission, and tractor
monitoring system. An ECM has the ability to detect problems with the electrical/electronic system and with engine
or machine operation. When an ECM detects an electrical or electronic system malfunction, the ECM will generate
a diagnostic code. Codes may be retrieved using two methods:
On-Board diagnosis using the Main display module
Electronic Technician (ET)
This work package describes On-Board diagnostics.
The Machine Monitoring System is designed to alert the operator of a problem in one or more of the machine sys-
tems that are covered. The main display module includes individual alert indicators for each machine system. The
action lamp and individual alert indicators will light when a problem occurs. Also, the action alarm will sound when
certain problems occur.
The main display module controls the Machine Monitoring System. This module receives information from the
switches, sensors, and other electronic control modules on the machine via the Machines Data Link. The main
display module processes all of the information. The module then activates various outputs. The outputs could be
in the display area of the main display module, the quad gauge module, the speedometer/tachometer module, the
action lamp, or the action alarm. The display components show the condition of the machine systems. The
operator or the service person can also obtain system diagnostic information.