Diagnosis - GILLIG LOW FLOOR Service Manual

Diagnosis

If an electrical component or system on the bus is having problems, first check the ladder charts and
electrical schematics to determine which multiplex modules and connections are responsible for the cir-
cuits in question. Then use the following troubleshooting list to help identify the problem:
Amber output circuit LED's on/off.
The amber LED for an output circuit (remember, the number on the amber LED is the circuit
number plus 8) indicates that the output circuit is ready but not active. If the load circuit is open,
the amber LED will be off. Possible causes include: burned-out bulb, bad connection between
multiplex module and coach electrical device, defective solenoid, etc.
Amber and red LED's for circuit both on.
If both the amber and red LED's for an output circuit are on (remember, the number on the
amber LED is the circuit number plus 8), check the fuses for the corresponding circuit on the
multiplex module. (On the T2-DIO-888-PWM and the T2-DIO-168S modules, when amber and
red LED's light simultaneously, this does not indicate a blown fuse. To check fuses on these two
modules, visual inspection is necessary.)
Red output circuit LED's on/off.
If a red output LED is on, this indicates that the processor has triggered the corresponding func-
tion. If the red output LED is off, this indicates that that this output is not active.
Red data communication status LED not flashing.
Each module's red data communication status LED (see Figure 9-39) should always be flashing
(except for master module D2). This indicates that the module is communicating with the rest of
the system. If a red data communication LED is not flashing, check the multiplex system cables
for loose connections or damage.
If none of these diagnostic procedures help, there may be a hardware or programming problem with the
multiplexing system itself. Contact the Gillig Field Service Department at (510) 785-1500 or
I/O Controls Corporation at (626) 812-5353 for advanced troubleshooting assistance.
DINEx Flash Codes
The COMM FAULT lamp on the dashboard Indicator Lamp Strip can display a flash code if there is any
DINEX module communication failure. The Day Run, Night Run, Park, or Rear Run switch must be on
to display these flash codes. The COMM FAULT lamp will light for a few seconds on initial power-up,
along with all of the other LED's on the Indicator Lamp Strip. After that, if the COMM FAULT lamp
remains off, this indicates that the DINEX modules are communicating. Use the following flash codes to
determine which module is failing.
Electrical System
392