JLG M450 ANSI Service Manual - Manual (Page 196)

SECTION 6 - JLG CONTROL SYSTEM
6-18 – JLG Lift – 3121127
3/3 Flash code 3/3 indicates that a contactor coil is short-circuited.
OVERLOADED VALVE SUPPLY-CHECK WIRING.
There is a high current draw from the valve supply when no valve is energized; this is probably due to a wir-
ing error at the ground module.
SHORT-CIRCUIT FORWARD CONTACTOR COIL
The forward contactor was not energized when required, due to coil overcurrent protection.
SHORT-CIRCUIT LINE CONTACTOR COIL
The line contactor was not energized when required, due to coil overcurrent protection.
SHORT-CIRCUIT REVERSE CONTACTOR COIL
The reverse contactor was not energized when required, due to coil overcurrent protection.
3/5 Flash code 3/5 indicates that there is a brake pressure problem.
BRAKES DID NOT LOCK
Brake pressure did not clear when the brake valve was deenergized.
BRAKES DID NOT RELEASE
No brake pressure was detected when running the pump motor and energizing the brake valve
4/2 Flash code 4/2 indicates that the controller is over temperature.
CONTROLLER TOO HOT - PLEASE WAIT
The controller heatsink temperature reached 75 degrees. The controller is shut down until it cools to below
70 degrees.
4/4 Flash code 4/4 indicates problems with the battery supply.
BATTERY LOW
Battery voltage is below 40V. This is a warning - the controller does not shut down.
BATTERY TOO HIGH - SYSTEM SHUT DOWN
Battery voltage is above 62V.
EMS recycle required.
BATTERY TOO LOW - SYSTEM SHUT DOWN
Battery voltage is below 33V.
EMS recycle required.
5/5 Flash code 5/5 indicates problems with vehicle speed or the encoder.
NO VEHICLE MOVEMENT DETECTED AT MAXIMUM POWER
No speed was measured with traction motor full on. This could be due to a traction motor fault, a power wir-
ing error, a speed encoder fault, the brakes not releasing (although brake Pressure is OK) or the vehicle
being overloaded so that the motor cannot turn the wheels.
DRIVE PREVENTED - BOTH SPEED ENCODERS FAULTY
Both speed encoder input voltages are out of range.
LEFT SPEED ENCODER FAULTY
The left speed encoder input voltages are out of range. The vehicle will continue to drive at cutback using
the right speed encoder.
RIGHT SPEED ENCODER FAULTY
The right speed encoder input voltages are out of range. The vehicle will continue to drive at cutback using
the left speed encoder.
SPEED ENCODERS READING INVALID SPEED
One or both speed encoders is indicating an impossible number of pulses. This is probably due to a faulty
speed encoder.
VEHICLE RUNAWAY - CHECK SPEED ENCODERS
Speed in the wrong direction was measured with traction motor full on. This is probably due to the speed
encoder being fitted incorrectly; it could also be due to a speed encoder fault or faults as for "NO VEHICLE
MOVEMENT DETECTED" with the vehicle on a grade.
Table 6-4. Help Descriptions and Fault Flash Codes