Case 580SR, Service Manual

Page: 337 / 1068

SECTION 21 - TRANSMISSION 271
SPEED SENSOR / FAULT CODE F2 AND F3
A fault indication on the display is given to warn of
this problem.
If a speed sensor fault is detected the microproces-
sor will modify its behaviour in the following areas:
Z
no upshifts will be allowed above second gear.
Z
direction change while in F3 or F4: the actual re-
versal is preceded by a downshift sequence until
second gear is obtained.
Z
4WD braking remains operative.
NOTE: that the system response in this case is iden-
tical to the response in case of a power supply over-
voltage.
Speed sensor test using the turbine speed dis-
play
NOTE: a lamp test is performed prior to the speed
sensor test and monitors all LEDs are operational.
SPEED SENSOR TEST REQUIREMENTS: power-
shift lever to be in reverse position, twist to upshift
(keep the shift lever in this position during power up)
turn the ignition on and start the engine.
With engine running return Powershift lever to neu-
tral position and then place lever in forward and twist
to upshift. Increase engine speed and compare with
the table opposite.
IMPORTANT: self test modes can only be started
WHILE POWERING UP (ignition on). Leaving the
self test mode is done by switching OFF the power
to the Microprocessor (ignition off).
In this mode driving is possible.
The LED corresponding with the table opposite illu-
minates to indicate the torque converter turbine
speed and increases with engine revs.
NOTE: application of the foot brakes during this test
will reduce the turbine speed to zero.
F28361
F
1 2 3 4
1 2
Blinks
Blinks
Blinks Slower
Blink
3 4 5
5
6 7 8
N R T N
Turbine rpm LED
0 1 blinks
0 - 249 1 on
250 - 499 2 on
500 - 749 3 on
750 - 999 4 on
1000 - 1249 5 on
1250 - 1499 6 on
1500 - 1749 7 on
1750 - 1999 8 on
above 2000 8 blinks
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