JLG TF6-42 Service Manual - Manuale (Pagina 202)

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2.2.11 Speed Sensor faults
The fault detection relies on a permanent monitoring of sensor current. If it gets too low, an open circuit
condition is assumed. Conversely, if it is too high, a short to ground is signalled.
INCORRECT MOUNTING OF SENSORS CANNOT BE DETECTED.
Any fault related to the drum speed sensor (A24-A25) results in the immediate selection Neutral, after
which the machine can only be operated in limp home mode. Additionally in Platform Control Mode
the controller reverts to SHUTDOWN permanently.
A fault related to the engine speed sensor causes platform drive and automatic shift to be disabled.
This causes SHUTDOWN in Platform Control Mode and a forced stop in Cabin-AWP mode. In other
modes the machine can be operated.
A sensor specific fault indication on the display is given to warn the driver of the problem.
Note that the parking brake input switch (push button) is connected to speed sensor input B11 and
uses the short circuit detection capability of this circuit to measure transitions on the button. These
'shorts' are not signalled to the driver. In stead they are used to toggle the state of the parking brake
2.2.11.1 Fault Codes for Speed Sensor Faults
60.00
· The sensor is not connected ( = open)
60.01
· The sensor is shorted to Ground
Note that the first two digits identify the speed sensor exhibiting the fault:
60 Optional output speed sensor fault A22-A23
61 Drum speed sensor fault A24-A25
62 Engine speed sensor fault A26-A27
63 Parking brake input fault (open only) B11
2.2.12 Analog Sensor Faults
Boom Function sensor fault (A11)
Faults related to this input are detected and flagged if properly setup in Flash memory. Any fault is
treated a 'not moving’.
Boom position sensor fault (A28)
The boom position sensor is actually a cascade of two proximity switches. The wiring is built up in such
way that power loss on the proximity switches simulates the 'extended' (i.e. safest possible) position.
Accelerator pedal sensor fault (A29)
If the accelerator pedal sensor produces an out of range value, the accelerator position is assumed to
be at 0%, causing the engine to return to low idle.
à This prevents automatic upshifts when driving in handler mode.
In CABIN-AWP mode the machine is brought to a safe stop using the service brakes.