Motrec T-448HD, Operator And Maintenance Manual

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Curtis PMC 1244 Manual 77
8 — DIAGNOSTICS & TROUBLESHOOTING
8
DIAGNOSTICS AND TROUBLESHOOTING
The 1244 controller provides diagnostics information to assist technicians in
troubleshooting drive system problems. The diagnostics information can be
obtained by observing the appropriate display on the handheld programmer, the
fault codes issued by the Status LED, or the fault display driven by the controller’s
Fault 1 and Fault 2 outputs. Refer to the troubleshooting chart (Table 5) for
suggestions covering a wide range of possible faults.
PROGRAMMER DIAGNOSTICS
The programmer presents complete diagnostic information in plain language.
Faults are displayed in the Diagnostic Menu (see column 2 in the troubleshooting
chart), and the status of the controller inputs/outputs is displayed in the Test
Menu.
Accessing the Diagnostic History Menu provides a list of the faults that have
occurred since the diagnostic history file was last cleared. Checking (and clearing)
the diagnostic history file is recommended each time the vehicle is brought in for
maintenance.
The following 4-step process is recommended for diagnosing and trouble-
shooting an inoperative vehicle: (1) visually inspect the vehicle for obvious
problems; (2) diagnose the problem, using the programmer; (3) test the circuitry
with the programmer; and (4) correct the problem. Repeat the last three steps as
necessary until the vehicle is operational.
Example:
A vehicle that does not operate in “forward” is brought in
for repair.
STEP
1: Examine the vehicle and its wiring for any obvious problems,
such as broken wires or loose connections.
STEP
2: Connect the programmer, select the Diagnostics Menu, and
read the displayed fault information. In this example, the display
shows “No Known Faults,” indicating that the controller has not
detected anything out of the norm.
STEP
3: Select the Test Menu, and observe the status of the inputs and
outputs in the forward direction. In this example, the display shows
that the forward switch did not close when “forward” was selected,
which means the problem is either in the forward switch or the switch
wiring.
STEP
4: Check or replace the forward switch and wiring and repeat the
test. If the programmer shows the forward switch closing and the
vehicle now drives normally, the problem has been corrected.
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