Hydraulic Solenoid Valve Coils - Toro Groundsmaster 4300-D Service Manual

Testing the Hydraulic Solenoid Valve Coils
Electrical System: Testing the Electrical Components
The Groundsmaster 4300-D hydraulic control manifolds use several hydraulic
solenoid valve coils for system control. The deck control manifold includes 2
solenoid valves (Figure
valves (Figure 181). When the solenoid coils are energized, the hydraulic valve
shift occurs to control the hydraulic fluid flow. The correct resistance of a coil can
be identified by measuring the height and diameter of the coil
to Solenoid Valve Coil Specifications Table (page
be done with the coil installed on the hydraulic valve.
Note: The 2 solenoid valve coils on the deck control manifold (PRV1 and PRV2)
are identical. The solenoid valve coils SV1 and PRV on the lift control manifold
are identical and are the same as those used on the deck control manifold. The
remaining lift control manifold coil (SV2) is different. To assist in troubleshooting,
identical coils can be exchanged. If the problem follows the exchanged coil, an
electrical problem likely exists with the coil. If the problem remains unchanged,
something other than the solenoid coil is the problem source (e.g., switch, circuit
wiring, and hydraulic problem).
Note: Before you disconnect the solenoid valve coils, test the solenoids and
their circuit wiring as TEC outputs with the InfoCenter display; refer to
InfoCenter Display for Troubleshooting (page
that the solenoid coils and circuit wiring are functioning correctly, then no more
testing is necessary.
1. Park the machine on a level surface, lower the cutting decks, shut off the
engine, set the parking brake, and remove the key from the key switch.
2. To get access to the deck control manifold, raise and prop the operator seat.
To get access to the lift control manifold, remove the operator floor plate.
3. Identify the coil by measuring the height and diameter of the coil.
4. Disconnect the wire harness connector from the hydraulic solenoid valve
coil that is to be tested.
Note: Before taking the small resistance readings with a digital multimeter,
short the multimeter test leads together. The multimeter displays a small
resistance value (usually 0.5 ohms or less). This resistance is because of the
internal resistance of the multimeter and test leads. Subtract this value from
the measured value of the component that you are testing.
Note: The solenoid coil resistance should be measured with solenoid at
approximately 20°C (68°F). Resistance may be slightly different than listed
at different temperatures. Typically, a damaged solenoid coil will either be
shorted (very low or no resistance) or open (infinite resistance).
5. Use a multimeter (ohms setting), measure the resistance between the 2
connector terminals on the solenoid coil. The resistance for the solenoid coils
is identified in the Solenoid Valve Coil Specifications Table (page
Solenoid Valve Coil Specifications Table
Solenoid Valve Coil
PRV1 and PRV2 46.7 mm (1.84 inches)
(deck)
SV1 and PRV (lift) 46.7 mm (1.84 inches)
SV2 (lift) 35.8 mm (1.41 inches)
6. If the solenoid coil resistance is incorrect, replace the solenoid coil; refer to
Hydraulic Solenoid Valve Coils (page
180) and the lift control manifold includes 3 solenoid
5–26). If the InfoCenter verifies
Diameter
49.9 mm (1.96 inches)
49.9 mm (1.96 inches)
36.3 mm (1.43 inches)
5–91).
Page 5–74
(Figure 182). Refer
5–74). Testing of the coils can
5–74).
Height Resistance
7.1 ohms
7.1 ohms
8.8 ohms
Groundsmaster
16226SL Rev C
Using the
® 4300-D