Page 231 of 284

AUTOMATIC FREE-WHEELING HUB INDICATOR SYSTEM - Generallnformation 8-211
3. Automatic free-wheeling hub in free condition
For the free condition, although there are (when the vehicle is traveling) output signals from the vehicle-
speed sensor, there are no signals from the pulse generator, with the result that the memory circuit is
erased (because reset signals are output from the lock-discrimination circuit), and so the indicaotr light
does not illuminate.
I
Lock Use-detection
-discrimination
Memory ipeed sensor Ignition switch
Automatic free-
detection circuit
circuit
circuit
Automatic free-wheeling
indicator control unit -
hub i
Sub fusible link
link
Pulse generator cross-sectional view PULSE GENERATOR
Coil hgnet
16W1547
rator
Front out-
put shaft
16W1546 The pulse generator is located at the rear part of the front
output shaft of the transfer, and is composed of the magnet,
the coil and the pole (iron core).
When a magnetic material (iron, nickel, etc.) is brought close
to and moved away from the pole (iron core), the magnetic flux
within the pole changes, thus generating AC voltage in the
coil.
Because the front output shaft does not rotate when the
automatic free-wheeling hub is in the free condition, there is
no generation of AC voltage in the pulse generator.
In the locked condition, however, the front output shaft and
the pulse rotor rotate, with the result that the magnetic flux
(within the p o e I (’ Iron core) of the pulse generator) changes in
accordance with the rotations of the pulse rotor, thereby
generating AC voltage in the coil.
This AC voltage is transmitted to the automatic free-wheeling
hub indicator control unit.
STB Revision
Page 232 of 284

8-212 AUTOMATIC FREE-WHEELING HUB lNCDlCATOR SYSTEM - $%%60n’~at’on’
Speedometer
I
iensor Vehicle-speed
sensor
16W1506
12R0058
Circuit Diagram
16W153
SPECIFICATIONS
GENERAL SPECIFICATIONS VEHICLE-SPEED SENSOR (REED-TYPE SWITCH)
The vehicle-speed sensor functions to substitute pulse signals
for the rotations (vehicle speed) of the transmission’s output
gear;/ t i is located within the speedometer.
Pulse signals are generated when the speedometer cable
rotates.
AUTbMATlC FREE-WHEELING HUB INDICATOR
CONTROL UNIT
The control unit is located at the upper part of the right cowl
side.
The control unit is composed of the pulse-detection circuit
(which receives the input signals from the pulse generator),
the vehicle-speed-detection circuit (which receives the input
signals from the vehicle-speed sensor), the lock-discrimination
circuit (which, based on both of these input signals, judges the
condition of the automatic free-wheeling hub ‘and then trans-
mits indicator output signals to the memory circuit), and the
memory circuit (which “memorizes” the indicator output
signals from the lock-discrimination circuti).
Items
Automatic free-wheeling hub indicator light
Pulse generator
Type
Vehicle-speed sensor
Type
Pulse generation
SERVICE SPECIFICATIONS
Specifications
W (SAE trade number) 1.4(74)
Magnet coil type
Reed switch type
4 pulses/ rotation
NOORG-
Items Specifications
Standard values
Pulse generator resistance
R 215-275
Vehicle-speed sensor output voltage V
When OFF 4 or more 1 STB Revision
When ON 0
Page 234 of 284
8-214 AUTOM TIC FREE-WHEELING VU6 INDICATOR SYSTEM - Circuit Diagram
I
m I IA-21 m
v?~
r:
BI I To column switch
2
[Refer to P.8-461 CT
= 9’i A I
I
m z
I ’
c: d
I ’
LR
!J
I I 1
CIRCUIT DIAGRAM
AUTOMATIC FREE-WHEELING HUB INDICATOR SYSTEM
CIRCUIT
F==e=%
Battery lu-!
A-02 Sub fusible link
- 15-w r-)5-w 0.5-G
2-w
I I I I
Main fusible
link
7
N
-22
3
Pulse c:
generator
h Ignition switch
I /Locking check circuit 1
q IIEI Combination meter
Automatic free-wheeling hub
indicator control unit
1 B R
Em El1 Y L
Remark
For information concerning the ground points (example: q ),
refer to P.8-7.
37W610
Wiring color code
B: Black Br: Brown
G: Green L: Blue
LI: Light blue Lg: Light green
0: Orange P: Pink “,r: RG,‘d”Y
Y: Yellow
W: White
1 STB Revision
Page 235 of 284
AUTOMATIC FREE-WHEELING HUB INDICATOR SYSTEM - Pulse Generator 8-215
PULSE GENERATOR
REMOVAL AND INSTALLATION NOBRJM
Removal steps
I. Pulse generator
2. O-ring
NOTE
(1) Reverse the removal procedures to reinstall
(2)
q : Non-reusable parts
I 16WO92 i
l Check whether or not metal particles are adhered to the
pole (iron core) of the pulse generator.
l Check whether or not the installation bolts of the pulse
rotor or the pulse generator are loose.
(For detailed information concerning the pulse rotor, refer
to GROUP 21 TRANSMISSION - Transfer.)
CHECKING PULSE GENERATOR RESISTANCE
Check whether or not the resistance between the terminals
shown in the figure is within the standard value range.
Standard value : 215 - 275 LR
If the resistance is not within the standard value range, replace
the pulse generator.
1 STB Revision