Troubleshooting
2200 SRM 1286
Tiller Oscillation and Bias (EPAS Option)
Tiller oscillation (Chattering) and Bias of the Elec-
tronic Power-Assist Steering Option is not linked to
any electrical failure within the End Rider unit. It
is caused by a physical/mechanical issue rather than
an electrical one. The replacement of EPAS Motor,
Torque Sensors, or Controller is not necessary in this
occasion. Certain areas of the truck must be visually
and tactically inspected when the oscillation/chatter-
ing symptoms occur to identify the cause and elimi-
nate the oscillation or bias of the tiller.
Inspect the following components to troubleshoot
chattering or bias in the EPAS (option) system:
1.
Casters: adjust casters accordingly to satisfy the
currently installed tire size. Using unnecessary
shims on the casters takes off the weight from
the drive tire making the system susceptible to
chattering.
2.
Drive tire: shall be in good condition. A worn
out tire causes the same effect as having unnec-
essary shims on the casters. The tire must have
sufficient grip against the floor, and if it does not
adjust casters as necessary.
3.
Loose gears: confirm that the gear of the EPAS
motor and the gear mounted on the bracket are
not loose and adjust the bracket as necessary to
minimize the backlash between the EPAS motor
gear and the MDU gear.
4.
Uneven pull rods: this misalignment of the truck
causes unwanted change in the torque signal,
therefore starting the effect of the oscillation.
5.
Assist level: assist levels 7 through 10 provide
excessive assistance and cause an increase of the
backlash in the system, which is a root caused of
the chattering. Lower assist level as necessary.
After ensuring all the aforementioned requirements
are met, the system must be calibrated as mentioned
in the calibration procedure.
Refer to Electrical
System 2200 SRM 1451 or Electrical System
2200 SRM 1287, Calibration, Power Assist Steer
Sensor.
STATUS CODES
Make sure the parameter values are correct for your
lift truck to ensure the trouble is not just an incorrect
setting. See function settings to set the correct pa-
rameter values. If there is no status code display and
the lift truck does not operate correctly, there may be
a fault in the master controller.
The status codes are numbers for malfunction or lift
truck operation that are not correct and that the mo-
tor controller can sense. The master controller will
indicate this code number on the LCD screen of the
display panel.
NOTE:
There are identifiers to determine which de-
vice generated the code:
Xy = XXXX (Co 23538)
Co = Controller
Ep = PAS Unit
Ti = Steer Handle Card
The controller senses the following types of malfunc-
tion:
• Input voltages that are too high or too low
• Input voltages in the wrong sequence or
• Correct input voltages that occur at the wrong time
NOTE:
A status code indication does not always mean
that there is a malfunction. A temporary operation
condition can cause a status code display.
These code numbers are only indicators that may
help diagnose a possible malfunction. A short de-
scription of the different status codes is shown in Ta-
ble 2.
The Fault Message charts in this section have a more
complete description of the status code, the circuit
that has generated the input for the status code, the
symptom, and the possible cause.
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