JLG T350 Troubleshooting Manual page 118

SECTION 3 - COMPONENT CHECKS
approximately ½ of the available Battery Voltage will be applied to the pump motor. Similarly, the MOSFET are On continu-
ously (100% Duty Cycle) to apply all available Battery Voltage to the pump motor.
Series DC
Pump Motor
When the Control System is energized, the voltage at the P Terminal will be approximately +24V (referenced to B-) when the
pump is static. The A (M2) Terminal will be approximately at +1V (referenced to B-) when the pump is running at full speed.
Common Difficulties
The following difficulties can be examined using the JLG Analyzer, a voltmeter, and simple hand tools. Unless otherwise
noted, the Control System shall be energized in Ground Mode during testing. The vehicle should be placed on a firm, level
surface for all analysis.
Ground Module Interlocks
There are a variety of interlocks that prevent Lift Up due to system events (Tilted, Tilt Sensor Not Calibrated, etc.). Before
investigating Pump System issues, examine the JLG Analyzer's HELP Menu while attempting to Lift Up from Ground Mode.
Refer to Section 2. Troubleshooting by Fault Messages for explanations of the Help Messages.
Power Module Diagnostic Issues
The Power Module executes a self-test during every power-up to ensure proper functionality. If a Diagnostic Issue is
detected, the Power Module will not energize the Line Contactor. Instead, it will flash the Green LED.
Open-Circuit between M1 Terminal and Pump Motor Positive Terminal
This issue will prevent the Pump Motor from operating. Under DIAGNOSTICS -> PUMP , the JLG Analyzer will show PUMP
PWM 100% and PUMP CUR 0.0A when Lift Up is operated from Ground Mode.
The voltage measured between the Pump Motor Positive Terminal and Ground Reference should be 24V. If it is not, examine
the cable between the terminal and the Power Module compartment. Inspect crimps for corrosion and ensure that bolted
connections are tight. Ensure that the cable is not crushed.
Open-Circuit between Pump Motor Negative Terminal and M2 Terminal
This issue will prevent the Pump Motor from operating. Under DIAGNOSTICS -> PUMP , the JLG Analyzer will show PUMP
PWM 100% and PUMP CUR 0.0A when Lift Up is operated from Ground Mode.
After ensuring there is not an Open-Circuit between the M1 Terminal and Pump Motor Positive Terminal, check that the volt-
age measured between the Pump Motor Negative Terminal and Ground Reference is 24V. If not, examine the issues within
Open-Circuit Pump Motor. This voltage should ramp to approximately 0V when Lift Up is operated from Ground Mode. If not,
examine the cable between the terminal and the Power Module compartment (M2 Terminal). Inspect crimps for corrosion
and ensure that bolted connections are tight. Ensure that the cable is not crushed.
3-118
Ignition Power (X002.3)
CAN HI
CAN LO
Figure 3-1. Power Module Circuit
T350 T500J
Line Contactor
(M 1)
+B
A
(M2)
-B
60Ω
Power Module
24V
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