Page 998 of 1226
Automatic Transmission/Transaxle -
Vehicles With: 4Speed Automatic
307-01 -38 Transmission (AW81-40) 307-01 -38
DESCRIPTION AND OPERATION
Consequences of signal failure:
NoTCC,
no torque reduction, no shift timing adaptation,
no 4th
gear.
TR sensor
The TR sensor serves to signal the currently
selected transmission range to the transmission
control unit.
It is a switch which transmits the selected
transmission range directly to the transmission
control unit.
In addition, the starter inhibit relay is actuated by
the PCM via the TR sensor when the selector lever
is in the positions "P" or
N.
In selector lever position "R the backup lamp relay
is also actuated via the TR sensor.
The transmission control unit uses this signal for:
Controlling the main line pressure,
Gearshift control,
Engagement of the TCC,
Shift timing adaptation during upshifts,
Shift timing adaptation during shifts from 3rd to
4th gear,
Shift timing adaptation during shifts from 4th to
3rd gear,
Reverse gear safety strategy,
Avoidance of gearshift judder during
engagement of a transmission range,
Torque reduction when pulling away.
Consequences of signal failure:
NoTCC,
no shift timing adaptation.
2006.0 Fiesta 1212006 G380530en
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Page 999 of 1226
Automatic Transmission/Transaxle -
Vehicles With: 4-Speed Automatic
307-01 -39 Transmission (AW81-40) 307-01 -39
DESCRIPTION AND OPERATION
TFT sensor Overdrive switch
The TFT sensor is located in the oil pan on the
main control body and is part of the transmission
wiring harness.
It measures the current transmission fluid
temperature and sends the signal to the
transmission control unit.
The transmission control unit uses this signal for:
Cold start mode,
Engagement of the TCC,
Shift timing adaptation during upshifts,
' , Shift timing adaptation during shifts from 3rd to
4th gear,
Shift timing adaptation during shifts from 4th to
3rd gear,
Overheating protection mode.
Consequences of signal failure:
NoTCC,
no shift timing adaptation,
no 4th gear. The overdrive switch
is located on the selector
lever.
It allows the driver to suppress or enable gearshifts
into 4th gear when
"D" is selected.
The signal from the overdrive switch is transmitted
to the transmission control unit.
When gearshifts into 4th gear are suppressed, the
transmission control unit sends a corresponding
signal via the CAN
databus to the instrument
cluster. The instrument cluster then actuates the
overdrive indicator lamp.
Consequences of signal failure:
no suppression of gearshifts into 4th gear.
2006.0 Fiesta 1212006 G380530en
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Page 1000 of 1226
Automatic Transmission/Transaxle -
Vehicles With: 4-Speed Automatic
307-01 -40 Transmission (AW81-40)
307-01 -40
DESCRIPTION AND
OPEMION
Driver's side door ajar switch
The door ajar switch is located in the door lock on
the driver's side.
When the door is closed a ground connection is
signalled to the transmission control unit.
When the door is opened this ground connection
is interrupted.
The transmission control unit uses the signal from
the driver's side door ajar switch to warn the driver
if the selector lever is not in position
"P" and the
driver's door is open.
In this case the transmission control unit transmits
the warning tone request via the CAN
databus to
the instrument cluster.
The instrument cluster passes this request on to
the GEM, which then generates a warning tone.
Consequences of signal failure:
no warning tone request.
Actuators
Main regulating valve
Item Description
I 1 I Main regulating valve I
The main regulating valve is a proportional valve
which converts the applied electric current into a
proportional hydraulic pressure.
The currentless state corresponds to maximum
pressure.
/
The main regulating valve is used to determine the
main line pressure and therefore the actuating
pressure for the clutches and brakes.
Consequences of signal failure:
hydraulic emergency running mode.
SSA and SSB shift solenoid valves
Item Description
2006.0 Fiesta 1212006 G380530en
1
2
SSA
SSB
(- t..
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Page 1001 of 1226
Automatic Transmission/Transaxle -
Vehicles With: 4-Speed Automatic
307-01
-41 Transmission (AW81-40) 307-01 -41
DESCRIPTION AND OPERATION
The SSA and SSB shift solenoid valves are used In
their currentless state they are open.
to switch the different hydraulic paths in the main
Consequences of signal failure: control body. hydraulic emergency running mode.
They are actuated by the transmission control unit
according to the required gear.
Actuation of the SSA and SSB shift solenoid valves
Shift timing solenoid valve
gear
I st gear
2nd gear
3rd gear
4th gear
kern Descri~tion
I 1 I Shift timing solenoid valve I
SSA On
On Off
Off
The shift timing solenoid valve is used to precisely SSB
On Off
Off
On
control the timing of the engagement and
disengagement of the
I st3rd gear clutch.
In addition, it is also used to prevent engagement
of reverse gear if the driver moves the selector
lever to "R" while the vehicle is driving forwards at
a speed in excess of
11 kmlh.
It is actuated by the transmission control unit
according to requirements.
In its currentless state the solenoid valve is closed.
Consequences of signal failure: hydraulic emergency running mode.
Shift solenoid valve, TCC
Item Description
I 1 I Shift solenoid valve, TCC I
The TCC shift solenoid valve is used to engage or
disengage the TCC.
It is actuated by the transmission control unit
according to requirements.
In its currentless state the solenoid valve is open
and the TCC is not engaged.
Consequences of signal failure:
Engagement of the TCC.
2006.0 Fiesta 1212006 G380530en
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Page 1002 of 1226
Automatic Transmission/Transaxle -
Vehicles With: 4-Speed Automatic
Transmission
(AW81-40)
DESCRIPTION AND OPERATION
Starter inhibit relay
2006.0 Fiesta
12/2006 G380530en
Item Description The starter inhibit relay is located in the central
1 Starter inhibit relay junction
box (CJB).
In the selector lever positions "P" and "Nu a ground N0TE:The engine cannot be started if the electrical signal is directed from the PCM via the TR sensor connector is disconnected from the TR sensor.
to the starter inhibit relay, as a result of which the
starter inhibit relay is actuated.
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Page 1003 of 1226
Automatic Transmission/Transaxle -
Vehicles With: 4-Speed Automatic
307-01 -43 Transmission (AW81-40) 307-01 -43
DESCRIPTION AND OPERATION
Backup lamp relay
The backup lamp relay is located in the relay box results inthe locking pin being pulled back, and
in the engine compartment. the
selector lever can be moved out of "P".
Item Description When the ignition is switched on, the selector lever
i 1 When the selector lever is in position "R the The ground connection to the solenoid for
the . , backup lamp relay receives a ground signal from ignition key removal inhibitor is also made via the
the TR sensor and actuates the backup lamps as selector lever lock solenoid in all selector lever
a result. positions except "P".
1
Consequences of signal failure:
backup lamps inoperative. Backup lamp relay
Selector
lever lock solenoid
lock solenoid is actuated by depressing the brake
pedal (sianal from the stoplamp switch). This
Item Description
1 I Locking pin
The selector lever lock solenoid is part of the
selector lever. Consequences of signal failure:
If the signal from the
stoplamp switch is missing
or the ground connection is interrupted, then
the selector lever can no longer be moved out
of the position
"P".
The selector lever lock can be manually released
by removing the cover and pressing a suitable
object into the opening on the selector lever until
the selector lever can be moved out of the position
IIPlr.
The selector lever then re-locks if it is moved back
to "P".
2006.0 Fiesta 1212006 G380530en
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Page 1004 of 1226
Automatic Transmission/Transaxle -
Vehicles With: 4-Speed Automatic
307-01
-44 Transmission (AW81-40) 307-01 -44
DESCRIPTION AND OPERATION
Solenoid for the ignition key removal
inhibitor
Solenoid for the ignition key removal
inhibitor
The solenoid for the ignition key removal inhibitor
is integrated in the ignition lock.
With the selector lever in position
"P", the ground
connection via the selector lever lock solenoid is
interrupted.
The ignition key can be turned to
"0" and removed
from the ignition lock.
In all other selector lever positions the ground
connection is made via the selector lever lock
solenoid.
The locking pin of the solenoid for the ignition key
removal inhibitor engages in the ignition lock.
The ignition key cannot be turned to
"0" and
removed from the ignition lock.
Consequences of signal failure:
A short to ground will make it impossible to
remove the ignition key from the ignition lock.
A break in the electrical circuit will make it
possible to remove the ignition key from the
ignition lock in all selector lever positions.
2006.0 Fiesta 12/2006 G380530en
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Page 1005 of 1226
Automatic Transmission/Transaxle -
Vehicles With: 4-Speed Automatic Transmission
(AW81-40)
DIAGNOSIS AND TESTING
Automatic Transaxle
Special Tool(s)
Hydraulic Pressure Gauge (0
- 60 bar)
307-20 1
General Equipment Worldwide
~ia~noitic System (WDS)
Inspection and Verification
1. Verify the customer concern.
2. Visually inspect for obvious signs of mechanical
or electrical damage.
Visual
lns~ection Chart
I Mechanical I Electrical I
3. If an obvious cause for an observed or reported
concern is found, correct the cause (if possible)
before proceeding to the next step.
4. If the cause is not visually evident, verify the
symptom and refer to the Diagnostic Trouble
Code Chart.
Damaged shift
mechanism
Transaxle fluid leaks
Damaged transaxle
casing
.I
- Diagnostic Trouble Code Chart
Fuse(s)
Electrical
connector(s)
Diagnostic Trouble Code Charts
Symptom Possible Sources Action
I A207 Checksum error I Transmission control module I REFER to WDS.
E516 CAN bus OFF sensor
error CAN bus.
D9OO CAN bus no communica-
tion error
PO706 Transmission range
(TR) sensor error
PO707 Transmission range
(TR) sensor circuit low input
CAN bus.
Inhibitor switch.
Inhibitor switch circuit(s).
lnhibitor switch.
lnhibitor switch circuit(s).
PO712 Transmission fluid
temperature circuit
- low input
REFER to WDS.
REFER to WDS.
3 Transmission fluid
temperature circuit
- high input
2006.0 Fiesta 1212006 G371498en
Transmission fluid temperature
sensor.
Circuit(s).
PO71 7 lnput speed sensor
circuit no signal
REFER to WDS.
Transmission fluid temperature
sensor.
e Circuit(s).
lnput speed sensor.
Circuit(s).
REFER to WDS.
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