SAFETY
Safety - 21
4500
Safety Procedures
Testing the Safety Interlock System
WARNING
Never operate the power unit if the safety interlock
system is malfunctioning. Do not disengage or bypass
any switch. Failure to heed warning could result in
injury to yourself and others, or damage to property.
CAUTION
The daily inspection should be performed prior to
initial startup for the day.
Perform the following safety interlock tests daily. Before testing, park the power unit on a level surface,
place wheel chocks in front and back of wheels, and place the high/low range shift lever in the neutral
position. After testing is complete, place the high/low shift lever in either high or low range, set the parking
brake, and remove the wheel chocks.
Tests 1-4
test the ‘Engine Start’ function. For each test, turn the key to the RUN position (do not start the
engine). As listed for each test, engage or disengage the parking brake, place the SDLA in neutral or out of
neutral, and sit on the seat or raise body weight from seat. The engine starter should or should not engage
as described for each test.
Tests 5-9
test the ‘Engine Run’ function. For each test, start the power unit so that the engine is running.
As listed for each test, engage or disengage the parking brake, place the SDLA in neutral or out of neutral,
and sit on the seat or raise body weight from seat. The engine should continue running or stop running as
described for each test.
Tests 10-13
test the ‘PTO’ function. For each test, turn the key to the RUN position (do not start the
engine). As listed for each test, place the PTO switch in the ON or OFF position and sit on the seat or raise
body weight from seat. The electric PTO clutch will make an audible noise when it engages or disengages.
Engine
Start
Test
Number
Parking Brake
Engaged
Forward/Reverse Control
(SDLA) in Neutral
Operator Present in Seat
Engine Starts
1
No
Yes
Yes
No
2
Yes
No
Yes
No
3
Yes
Yes
No
Yes
4
Yes
Yes
Yes
Yes
Engine
Run
Test
Number
Parking Brake
Engaged
Forward/Reverse Control
(SDLA) in Neutral
Operator Present in Seat
Engine Runs
5
Yes
Yes
Yes
Yes
6
Yes
Yes
No
Yes
7
Yes
No
No
No
8
Yes
No
Yes
No
9
No
Yes
No
No
PTO
Test
Number
PTO Switch
Operator Present in Seat
PTO Clutch
10
Off
Yes
Off
11
Pull to ‘On’ Position
No
No
12
Pull to ‘On’ Position
Yes
Yes
13
On
Raise Operator Body Weight
from Seat
PTO Disengages
(1/2 second delay)
If the power unit fails any one of the safety interlock tests, refer to the troubleshooting section for using the
TCM (tractor control module) to diagnose electrical problems.
