Toro 41188, Service Manual

Page: 142 / 353

Multi Pro 1750
Page 5 − 40
Electrical System
Traction Speed Sensor
The traction speed sensor is attached to the upper
transaxle cover (Fig. 41). The sensor uses a magneti-
cally based, Hall Effect integrated circuit. As the differ-
ential ring gear in the transaxle turns, the sensor
accurately senses the movement of the gear teeth pass-
ing by the sensor. The sensor white connector wire (pin
A) is the positive lead, the black wire (pin C) is the
ground lead and the blue wire (pin B) is the signal output.
The Toro Electronic Controller (TEC) monitors the op-
eration of the speed sensor (input). Information from the
speed sensor is used by the speed lock system and for
product application calculations. The speed sensor
must be calibrated for accurate speed calculations (see
Machine Operator’s Manual).
Testing
1. Park machine on a level surface, stop engine and en-
gage parking brake.
2. Disconnect machine wire harness from speed sen-
sor.
3. Test the machine wire harness to the speed sensor:
A. Set the ignition switch to the RUN/PREHEAT po-
sition.
B. Connect a jumper wire across the ground (−) pin
C and the signal (+) pin B (Fig. 42A). Have an assis-
tant watch the InfoCenter Display as you open and
close the connection across the pins multiple times.
Vehicle speed readings other than 00.0 should ap-
pear on the InfoCenter Display.
C. Remove the jumper wire.
D. Use a multimeter set to DC voltage and check for
12 VDC across the supply (+) pin A and ground (−)
pin C of the machine wire harness (Fig. 42B).
E. Turn the ignition switch to OFF.
4. Test the speed sensor:
A sensor test harness is required to quickly check sen-
sor operation without removing the sensor from the
wheel motor.
NOTE: Instructions for fabricating and using a traction
sensor test harness can be found in the Special Tools
section of this chapter or contact your Authorized Toro
Distributor for assistance.
1. Speed sensor
2. Flange head screw
3. Seal
Figure 41
1
2
3
1
Figure 42
1. Machine wire harness
connector
2. Jumper wire
3. Multimeter probe (typ.)
3
12 VDC
A
B
2
1