JLG 340AJ Service Manual - Manual (Page 301)

SECTION 6 - JLG CONTROL SYSTEM
3121259 – JLG Lift – 6-57
DRIVE VALVES – SHORT TO
BATTERY 33318 The Ground Module detects a short to battery at either the Drive For-
ward or Drive Reverse valve. Ground Module Drive Forward
and Reverse outputs are dis-
abled and open the ground cur-
rent return path. Inspect wiring for physical
damage and check for wire
continuity. Cycle power to clear
the fault.
DRIVE FORWARD VALVE –
SHORT TO GROUND 33319 The Ground Module detects a short to ground at the Drive Forward
Valve output. Ground Module Drive Forward
and Reverse outputs are dis-
abled. Inspect wiring for physical
damage and check for wire
continuity. Check for coil dam-
age or shorting condition in
connector. Cycle power to clear
the fault.
DRIVE REVERSE VALVE – OPEN
CIRCUIT 33320 The Ground Module detects an open circuit at the Drive Reverse Valve
output. The Ground Module suspends
Drive Forward/Reverse com-
mands and reverts to Open Cur-
rent loop control for Drive; Drive
speed is limited to Creep after
both Drive Forward/Reverse
controls have been returned to
neutral and the 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.
DRIVE REVERSE VALVE –
SHORT TO GROUND 33322 The Ground Module detects a short to ground at the Drive Reverse
Valve output. Ground Module Drive Forward
and Reverse outputs are dis-
abled. Inspect wiring for physical
damage and check for wire
continuity. Check for coil dam-
age or shorting condition in
connector. Cycle power to clear
the fault.
DRIVE – CURRENT FEEDBACK
READING TOO LOW 33331 The Ground Module calls for current greater than 250mA, but the
actual current is at least 125mA less than the called for current for
more than 1 second The Ground Module suspends
Drive Forward/Reverse com-
mands and reverts to Open Cur-
rent loop control for Drive; Drive
speed is limited to Creep after
both Drive Forward/Reverse
controls have been returned to
neutral and the machine is not
Enabled. Part of the commanded current
is being divided either prior to
the solenoid connection or on
the ground return path. Inspect
wiring for physical damage and
check for wire continuity and a
low resistance return path.
Cycle power to clear the fault.
LIFT UP VALVE – SHORT TO
GROUND 33406 The Ground Module detects a short to ground at the Lift Up Valve out-
put. Lift Up is disabled; Lift Down
speed is limited to Creep Inspect wiring for physical
damage and check for wire
continuity. Check for coil dam-
age or shorting condition in
connector. Cycle power to clear
the fault.
Table 6-10. 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