IQ DISPLAY MODULE (IQDM) AND IQDM-P
DIAGNOSTICS: IQ SYSTEM
Faults Menu
13
FAULTS MENU
The
faults
menu is accessed by using the up or down arrow to scroll to
faults
and pressing the right arrow key to
activate the menu.
Faults displayed in the
faults
menu will aid the trained technician in troubleshooting the vehicle. Faults displayed often
indicate which components in the electrical system need to be tested.
Since the
faults
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 handset while the vehicle is in motion. A technician
can monitor the handset while traveling as a passenger in the vehicle. Failure to heed this warning
could result in severe personal injury or death.
SYSTEM FAULTS
The
system faults
menu displays all of the faults detected by the speed controller since the last time the fault history
has been cleared. The faults displayed in this menu may or may not be currently active. Once a fault has been
detected, it is stored in the memory of the speed controller for display on the
fault history
menu. Each detected fault is
listed only once, even if the fault has occurred multiple times.
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 adjustment, improper
throttle position sensor installation)
• Improper wiring of electrical components
As shown above, there are many possible causes for faults to occur, and the speed controller has a programmed
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.
2009 Electric Precedent Maintenance and Service Manual
Page 13-7
