JLG 601S Operator Manual - Manual (Page 44)

SECTION 3 - MACHINE CONTROLS AND INDICATORS
3-12 – JLG Lift – 3121218
5. Engine Malfunction Indicator
On all machines prior to S/N 58209 and machines with a
Deutz engine prior to S/N 60188, the light turns on and
an alarm sounds when machine’s power system
requires immediate service. Any of the following condi-
tions will turn on light and alarm: low engine oil pres-
sure, high engine coolant temperature, clogged engine
air filter, low alternator output, clogged hydraulic oil
return filter, or clogged charge pump filter.
On machines with Ford engines from S/N 58209 and
machines with Deutz engines after S/N 60188, the light
indicates that the Engine Control System has detected a
malfunction and a Diagnostic Trouble Code has been
set in the system memory. Refer to the Service Manual
for instructions concerning the trouble codes and trou-
ble code retrieval.
The malfunction indicator light will illuminate for 2-3 sec-
onds when the key is positioned to the on position to act
as a self test.
6. Creep Speed Indicator
Illuminated (Green) for Boom functions when the boom
is above horizontal and the machine is tilted and for
Drive functions when the boom is above horizontal. The
indicator acts as a reminder that all functions are set to
the slowest speed.