Piston (Traction) Pump Control Solenoid Coils - Toro Groundsmaster 4500-D Series Service Manual

Piston (Traction) Pump Control Solenoid Coils

Solenoid Coil Testing
Electrical System: Component Testing
g309820
1. Piston pump
2. Forward solenoid coil
The piston (traction) pump uses an electronic control assembly for swash plate
rotation. Electrical outputs from the machine TEC controller are provided to
two (2) solenoid coils for pump control. The piston pump control assembly is
attached to the left side of the piston pump
Note: To assist in troubleshooting, the piston pump solenoid coils can be
exchanged because they are identical. If the problem follows the exchanged
coil, a problem with the coil likely exists. If the problem remains unchanged,
something other than the solenoid coil is the problem source (e.g. traction pedal,
circuit wiring, hydraulic problem).
1. Park machine on a level surface, lower cutting decks, stop engine, engage
parking brake and remove key from the ignition switch.
2. Locate piston pump solenoid coil to be tested
harness connector from solenoid coil.
Note: Prior to taking small resistance readings with a digital multimeter, short
the meter test leads together. The meter will display a small resistance value
(usually 0.5 ohms or less). This resistance is due to the internal resistance
of the meter and test leads. Subtract this value from the measured value
of the component you are testing.
Figure 216
3. Reverse solenoid coil
(Figure
Page 6–54
216).
(Figure 216). Disconnect wire
Groundsmaster ® 4500-D/4700-D
19245SL Rev A