Toro 30839 Operator's Manual page 28

The decal on the SCM only includes symbols. Three
LED output symbols are shown in the output box. All
Here are the logical troubleshooting steps for the SCM
device.
1. Determine the output fault you are trying to resolve
(PTO, START, or ETR).
2. Move key switch to the On position and ensure that
the red power LED is illuminated.
3. Move all input switches to ensure all LED's change
state.
4. Position input devices at appropriate position to
achieve the appropriate output. Use the following
logic chart to determine the appropriate input
condition.
Function Power In
ON Neutral
— —
Start
— —
Run (Off
Unit)
—
Run (On O
Unit)
—
Mow O
— —
Backlap
—
Hi Temp
• (–) Indicates a circuit closed to ground. – LED ON
• (O) Indicates a circuit open to ground or
de–energized – LED OFF
INPUTS
Start ON Brake PTO ON
ON
+
O O
O O O
—
O O
— —
O
—
O O
O
other LED's are inputs. The chart below identifies the
symbols.
Figure 28
5. If specific output LED is illuminated without
appropriate output function, check output harness,
connections, and component. Repair as required.
6. If specific output LED is not illuminated, check
both fuses.
7. If specific output LED is not illuminated and inputs
are in appropriate condition, install new SCM and
determine if fault disappears.
Each row (across) in the logic chart below identifies
input and output requirements for each specific
product function. Product functions are listed in the
left column. Symbols identify specific circuit condition
including: energized to voltage, closed to ground, and
open to ground.
In Seat Hi Temp
—
O
O O
—
O
—
O
O O
—
• (+) Indicates an energized circuit (clutch coil,
solenoid, or start input) LED ON.
• A Blank indicates a circuit that is not involved with
the logic.
28
OUTPUTS
Backlap Start ETR
+ +
O
+
O O
+
O O
+
O O
—
+
O
O O
PTO
O
O
O
+
+
O