Generac Power Systems GP Series Diagnostic Repair Manual page 37

Engine Diagnostic Tests
Section 5
Malfunction Indicator Lamp (MIL)
The MIL, located on the control panel, is used to indicate
when there is a fault in the engine system. The fault lamp
displays a 2-digit code by flashing a sequence of long
and short flashes. Long flashes are 1.2 seconds, and
short flashes are 0.25 second.
MIL Icons
• Condition 1: MIL is not lit, engine and key are OFF.
• Condition 2: MIL is dimly illuminated, constant on
(not flashing). This indicates the engine control
system is running properly (i.e. no fault) (A).
• Condition 3: MIL is brightly illuminated and
flashing. This indicates there is a fault with the
engine control system.
Fault Lamp Operation
• When the key is switched ON, the fault lamp will
illuminate for 0.5 seconds.
• If multiple failures have been detected, the fault
lamp will pause for 2 seconds between fault codes.
• Once the fault lamp has flashed all failure codes,
the fault lamp will pause for 5 seconds and then
repeat the codes. The lamp will continue to repeat
the codes until they are no longer active or the key
is switched OFF.
Fault Code Example:
= Long flash (1.2 sec)
= Short flash (0.25 sec)
Fault code 6-1 is displayed by: 6 long flashes = 6, one second pause, 1 short flash = 1
Diagnostic Repair Manual
•
Once the fault(s) have been resolved, the codes
will be saved in the ECM fault history memory.
Active Fault Codes – Shutdown
If a fault has been detected that requires stopping the
unit, the engine will automatically stop (or will not start)
and the lamp will flash the active fault code. Before the
unit can be restarted, the key must be first turned to the
OFF position to clear the active fault. The fault code will
be saved in the fault history memory when the key is
switched off.
Active Fault Code – Warning
If a fault has been detected, but does not require
stopping the unit, the fault lamp will flash the fault code
as long as the fault is present. If the fault is no longer
present, the lamp will stop flashing and the fault code will
be saved in the fault history memory.
Fault History Memory
The ECM will store a list of faults for three (3) ON-OFF
key cycles. To view previous faults, turn the key to the
ON position but do not start engine. After 30 seconds, the
fault lamp will flash previous faults stored in memory. The
fault codes will be displayed with flashing sequence just
like active faults. When the list is completed it will restart
at the beginning. To stop the sequence either switch key
OFF or start engine.
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