Scrub System, Cylindrical
114
Service Manual – SC6500
™
Troubleshooting
Problem
Cause
Correction
The scrub system
will not operate
Scrub deck sense R2
resistor fault (error code
01
displayed)
Scrub deck sensor resistor is unplugged or
damaged.
1. Check the resistor wiring for an open.
2. Substitute a new resistor and test the scrub deck
for correct operation.
Note that there are four different resistor values
used on the different deck types. See the electrical
diagram decal for the correct specification of the
resistor to replace.
Scrub motor overload (error
code
04
displayed)
1. Check for binding in the rotation of the brushes
and incorrect brush deck lift actuator operation.
2. Check the negative supply cable at the brush
motor for a wiring problem, and also the small
BRN current sense wire in the harness and A2 pin
J2-2.
3. Check for a short circuit in the brush motor or
wiring. Check for excessive belt tension and the
condition of the idler bearing.
Center brush motor
contactor coil overload (error
code
06
displayed)
1. Check for a
K3
coil wiring problem or a short
circuit (wire colors VIO and WHT/VIO).
2. Check the coil resistance. If the resistance is
below 75 ohms, replace the coil.
Note that the nominal coil resistance is 94 ohms for
both motor contactors.
Right brush motor contactor
coil overload (error code
07
displayed)
1. Check for a
K2
coil wiring problem or a short
circuit* (wire colors VIO & YEL/BLU).
2. Check the coil resistance. If the resistance is
below 75 ohms, replace the coil.
Scrub motor open (error
code
21
displayed)
1. Check for an open circuit in the motor wiring or for
a defective motor.
2. Check for 36 volts at the scrub motor that is not
running. If you get 0 Volts, replace the brush
motor contactor.
Center brush motor
contactor coil open (error
code
24
displayed)
1. Check for an open circuit in the
K3
coil and wiring
(wire colors VIO and WHT/VIO).
2. Test for 36V at the
K3
coil. If you get 0 Volts,
check the A2 control board assembly.
Center brush motor
contactor coil short to
ground (error code
25
displayed)
1. Disconnect the
K3
coil wiring (wire colors VIO
and WHT/VIO) and check to see if the code
disappears.
−
If the code disappears, replace the brush
contactor.
−
If the code does reappear, test the wiring for
a short back to the battery ground. Repair or
replace the defective wire.
2. If the above test doesn’t remove the code,
substitute a new A2 control board assembly.
