Diagnostics Menu
IQDM Service Tool Owner’s Manual
Page 11
DIAGNOSTICS MENU
The Diagnostics menu is activated by pressing the DIAGNOSTICS button on the IQDM
(Figure 8)
. When the
Diagnostics menu is active and there are more than 4
active
faults, the SCROLL DISPLAY buttons can be
used to scroll through the faults in the menu.
See following NOTE.
Any fault displayed in the Diagnostics
menu will aid the trained technician in troubleshooting the vehicle. Faults displayed in the Diagnostics menu
often indicate which components in the electrical system need to be tested and/or replaced.
NOTE:
The MORE INFO button can be pressed to display more information about the selected fault. The
item on the
top line
of the display screen is the selected item.
Note that the faults displayed in the Diagnostics menu may not include all of the faults listed in the Special
Diagnostics menu. This is because the faults displayed in the Diagnostics menu are faults that are currently
active. Once a fault has been detected by the speed controller, the code remains in the Diagnostics menu until
the problem has been corrected. In addition, the fault is stored in the speed controller’s memory for display in
the Special Diagnostics menu.
See Special Diagnostics Menu on page 15.
Since the Diagnostics menu is updated while the vehicle is in operation, the trained technician has the ability
to monitor the occurrence of faults in conditions or locations where a problem with vehicle performance has
been reported.
See following Warning.
∆
WARNING
• The vehicle operator should not monitor the IQDM while the vehicle is in motion. A technician
can monitor the IQDM while traveling as a passenger in the vehicle. Failure to heed this
warning could result in severe personal injury or death.
CAUSES OF FAULTS
Some common causes of faults are:
•
Loose, broken, or disconnected wires or connectors
•
Failed components
•
Improper adjustment or installation of electrical or mechanical components (examples: brake adjust-
ment, improper MCOR installation)
•
Improper wiring of electrical components
As shown above, there are many possible causes for faults to occur, and the speed controller has a pro-
grammed reaction to each fault that is based on the fault currently detected. The technician should be familiar
with the detected faults and the controller’s reactions to faults to ensure a proper diagnosis.
An example of a possible mis-diagnosis of a vehicle due to a fault: If the three-pin speed sensor wire has been
disconnected, the speed controller will detect a
speed sensor
fault. When a
speed sensor
fault is detected, the
controller responds to the fault by limiting the vehicle speed to 1/2 of its normal top speed. If the technician
reaches the conclusion that the vehicle is running slowly because batteries are heavily discharged, he has
made an improper diagnosis of the problem.
The vehicle speed controller should be checked for fault codes before any service is performed.
The speed controller, after detecting a fault, will respond in one or more of the following ways:
•
A. Reduce vehicle speed to zero by reducing armature current
•
B. Reduce vehicle speed to zero by reducing field current to zero
•
C. Turn off the solenoid
•
D. Cause the vehicle to run at half speed
Summary of Contents for IQDM
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