JLG 18RS Service Manual - Manual (Page 181)

SECTION 6 - JLG CONTROL SYSTEM
3121284 – JLG Lift – 6-39
FUNCTIONS LOCKED OUT –
CONSTANT DATA VERSION
IMPROPER 2520 The Ground Module detects a mismatch between programmed sec-
tions of the processor memory. Disable all machine and engine
functions (i.e., command
engine shutdown and do not
permit start). Reprogram the software so
that the memory values match.
Cycle Power.
BRAKE – SHORT TO BATTERY 331 The Ground Module detects a short to battery at the brake output. Disable Drive and Brake out-
puts. Inspect wiring for physical
damage and check for wire
continuity. Cycle power to clear
the fault.
BRAKE – OPEN CIRCUIT 332 The Ground Module detects an open circuit at the brake output. No response required. Inspect wiring for physical
damage. Check for a good con-
nection at the solenoid and for
wire continuity through this
circuit. Cycle power to clear the
fault.
LIFT UP VALVE – OPEN CIRCUIT 334 The Ground Module detects an open circuit at the lift up valve output. The Ground Module suspends
the Lift Up/Down command
and reverts to Open Loop Cur-
rent control for Lift; Lift speed is
limited to Creep after both Lift
Up/Down controls are returned
to neutral and the machine
controls are not Enabled. Inspect wiring for physical
damage. Check for a good con-
nection at the solenoid and for
continuity through the circuit.
With the solenoid discon-
nected, an open circuit voltage
of nearly 8.0V exists on the
Ground Module output pin for
diagnostic purposes. Cycle
power to clear the fault.
LIFT DOWN VALVE – SHORT TO
GROUND 335 The Ground Module detects a short to ground at the Lift Down valve
output. Ground Module Lift Up and
Down outputs are disabled. Inspect wiring for physical
damage and check for wire
continuity. Cycle power to clear
the fault.
LIFT DOWN VALVE – OPEN
CIRCUIT 336 The Ground Module detects an open circuit at the Lift Down valve
output. The Ground Module suspends
Lift Up/Down commands and
reverts to Open Loop Current
control for Lift; Lift speed is lim-
ited to Creep after both Lift Up/
Down controls have been
returned to neutral and
machine is not Enabled. Check for a good connection at
the solenoid and for continuity
through this circuit. With the
solenoid disconnected, an
open circuit voltage of nearly
8.0V exists on the Ground Mod-
ule output pin for diagnostic
purposes. Inspect wiring for
physical damage. Cycle power
to clear the fault.
GROUND ALARM – SHORT TO
BATTERY 3311 The Ground Module detects a short to battery at the Ground Alarm
output. No response required. Inspect wiring for physical
damage and check for wire
continuity. Cycle power to clear
the fault.
MAIN DUMP VALVE – SHORT
TO GROUND 3358 The Ground Module detects a short to ground at the Main Dump
Valve output. The Main Dump Valve output is
disabled. Inspect wiring for physical
damage and check for wire
continuity. Cycle power to clear
the fault.
Table 6-5. Fault Code Troubleshooting Information
Help Message DTC Condition Producing DTC
Control System Response or
Machine Condition
Corrective Action/
Operational Requirement
for Function Movement
and/or to Clear Fault