N2 And N3 Input Speed Sensors - ATSG 722.6 Service Manual

TFT SENSOR CHART
ATF TEMP VOLTAGE
-40C (-40F) 0.80
-30C (-22F) 0.88
-20C (-4F) 0.95
-10C (14F) 1.02
0C (32F) 1.09
10C (50F) 1.16
20C (68F) 1.23
30C (86F) 1.30
40C (104F) 1.37
50C (122F) 1.44
60C (140F) 1.51
70C (158F) 1.58
80C (176F) 1.65
90C (194F) 1.72
100C (212F) 1.79
110C (230F) 1.86
120C (248F) 1.93
130C (266F) 2.00
140C (284F) 2.08
150C (302F) 2.15
160C (320F) 2.22
170C (338F) 2.29
Figure 18
N3 Input
Speed Sensor
Technical Service Information
RESISTANCE
564.0
624.0
686.0
750.0
817.0
886.0
957.0
1032.0
1109.0
1189.0
1273.0
1306.0
1450.0
1545.0
1644.0
1747.0
1855.0
1968.0
2087.0
2211.0
2276.0
2479.0
Copyright © 2009 ATSG
N2 Input
Speed Sensor
Figure 19
AUTOMATIC TRANSMISSION SERVICE GROUP
ELECTRONIC COMPONENTS (CONT'D)

N2 and N3 Input Speed Sensors

The 722.6 transmission uses 2 input speed sensors
referred to as N2 and N3. Both speed sensors are
located in the electrical conductor plate, as shown in
Figure 19. The speed sensors are Hall Effect speed
sensors that are used by the TCM to calculate the
transmissions input speed. Since the input speed
could not be measured directly, two of the drive
elements are measured. N2 records the speed of the
front sun gear and N3 records the speed of the front
planetary carrier. Two input speed sensors were
required because both drive elements are not active in
all gears. The input sensors N2 and N3 will report the
same input speed in 2nd, 3rd or 4th gear. If the N2 and
N3 input speed signals are not the same in these gears,
then there is an issue with the transmission and the
DTC for "Input Speed Sensors Mismatch" will be set.
The N3 input speed sensor is not reported in 1st and
5th gears. The N2 input speed sensor is not reported
in Reverse. The Input Speed Sensor Overspeed is a
rationality check that is intended to indicate a major
transmission failure and will cause a loss of drive,
with transmission going to neutral.
Electronic Components
Continued on Page 20
Electrical
Conductor Plate
Copyright © 2009 ATSG
19