torque FORD FIESTA 2007 Repair Manual

Automatic Transmission/Transaxle -
Vehicles With: 4-Speed Automatic
307-01 -25 Transmission (AW81-40) 307-01 -25
DESCRIPTION AND OPERATION
Item Descriotion
I 1 I From the torque converter I
~l%ansmission input shaft I
1 4 1 Small sun gear I
1 6 1 Planet gear carrier I
1 8 1Short planet gear I
1 9 1 Long planet gear I
10 Annulus and
output wheel of the planetary
/ (gearset
I 11 I Intermediate gear stage I
1 12 1 Differential assembly I
1 13 12nd - 4th gear brake I
1 14 1 2nd gear one-way clutch I
1 15 1 Large sun gear I - --
1 16 14th gear brake I
1 17 1 3rdl4th gear clutch I
~Iianetary gearset, rear I
I B I Planetary gearset, front I
Drive is transmitted from the torque converter (I)
to the transmission input shaft (2) and via the
3rdl4th gear clutch (1 7) to the planet gear carrier
(6).
The large sun gear (15) is held by the 4th gear
brake
(16), the 2nd gear one-way clutch (14) and
the 2nd-4th gear brake
(1 3).
N0TE:The short planet gears (8) and the small
sun gear (4) co-rotate, but they have no influence
on the transmission ratio.
The long planet gears (9) drive the annulus (10) in
the same direction of rotation as the output from
the engine.
The annulus is fixedly connected to the output
wheel of the planetary
gearset and drives the
intermediate gear stage
(11) in the opposite
direction of rotation to the output from the engine.
The intermediate gear stage drives the differential
assembly
(12) in the same direction of rotation as
the output from the engine.
2006.0 Fiesta 1212006 G380528en
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Automatic Transmission/Transaxle -
Vehicles With: 4-Speed Automatic
307-01 -27 Transmission (AW81-40) 307-01 -27
DESCRIPTION AND OPERATION
Item Description
I 1 I From the torque converter I
1 2 I Transmission input shaft I
1 4 ISmaII sun gear I
11 Planet gear carrier I
1 7 1 Reverse gear brake I
1 8 1Short planet gear I
1 9 1 Long planet gear I
10 Annulus and output wheel
of the planetary
I (gearset
I 11 I Intermediate gear stage I
1 12 1 Differential assembly I
1 15 1 Large sun gear I
1 18 1 Reverse gear clutch I
I A I Planetary gearset, rear I
I B I Planetary gearset, front I
Drive is transmitted from the torque converter (1)
to the transmission input shaft
(2) and via the
r reverse gear clutch (1 8) to the large sun gear (1 5).
The planet gear carrier
(6) is held by the reverse
gear brake
(7).
The large sun gear drives the long planet gears
(9) in the opposite direction of rotation to the output
from the engine.
N0TE:The short planet gears (8) and the small
sun gear (4) co-rotate, but they have no influence
on the transmission ratio.
The long planet gears drive the annulus (1
0) in the
opposite direction of rotation to the output from the
engine.
The annulus is fixedly connected to the output
wheel of the planetary
gearset and drives the
intermediate gear stage (I
I ) in the same direction
of rotation as the output from the engine.
The intermediate gear stage drives the differential
assembly (1 2) in the opposite direction of rotation
to the output from the engine.
2006.0 Fiesta 1212006 G380528en
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Automatic TransmissionlTransaxle -
Vehicles With: 4-Speed Automatic
307-01 -31 Transmission (AW81-40) 307-01 -31
DESCRIPTION AND OPERATION
The transmission control unit determines hill climb
mode or trailer operation from the change in throttle
; valve position supplied by the PCM in relation to
the acceleration of the vehicle.
Depending on the driving resistance, the
transmission control unit chooses between two
gearshift maps which have been specially
programmed for this purpose and in which the shift
timings are again chosen as a function of the
accelerator pedal position and the vehicle speed..
Hill descent mode
The hill descent mode is used to take better
advantage of engine braking during hill descents.
A 'hill descent' situation is recognised by the
transmission control unit if the vehicle is
accelerating without operation of the accelerator
pedal.
If in addition the brake is also depressed then the
transmission control unit automatically shifts back
from 4th into 3rd gear.
( ' Cold start mode
In order to reach operating temperature as quickly
as possible under low ambient temperatures,
gearshifts into 4th gear and engagement of the
torque converter clutch (TCC) are suppressed if
one of the following conditions is met:
Transmission fluid temperature below +20 "C
Coolant temperature below - 40°C
The following are actuated: SSA shift solenoid valve,
SSB shift solenoid valve,
Shift solenoid valve, TCC.
Overheating protection mode
The overheating protection mode serves to protect
the transmission against overheating and the
serious damage that this can cause.
If the transmission fluid temperature reaches a
temperature of around 135
"C, the transmission
control employs a shift pattern designed to prevent
a further increase in the transmission fluid
temperature. When
the transmission fluid temperature drops
back below approx. 125
"C, the transmission
control exits the overheating protection mode.
The MIL warning lamp is actuated by the
transmission control unit if the transmission fluid
temperature reaches approximately 140
"C.
The MIL warning lamp goes out again when the
transmission fluid temperature drops back to below
around 130
"C.
Main line pressure control
In order to ensure the highest possible efficiency
of the automatic transmission and to limit the power
losses from the fluid pump, the main line pressure
is adapted accordingly by the main regulating valve
as a function of the accelerator pedal position
(driver torque demand) and the selector lever
position.
This is influenced by the following variables:
Accelerator pedal position and actuation
Selector lever position
The following are actuated:
Main 'regulating valve
Engagement of the TCC
The TCC is engaged in 3rd and 4th gear depending
on the current driving situation.
Engagement is controlled in accordance with the
shift map stored in the control unit.
This is influenced by the following variables:
Accelerator pedal position and actuation,
Vehicle speed,
Selector lever position,
Transmission fluid temperature,
Coolant temperature.
The following are actuated:
Shift solenoid valve, TCC.
Torque reduction during gearshifts
In order to improve the quality of gearshifts and to
avoid gearshift judder, the engine torque is reduced
by the PCM in response to a request from the
transmission control unit during gearshifts.
The engine torque is also reduced during
engagement and disengagement of the TCC.
2006.0 Fiesta 1212006 G380530en
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Automatic Transmission/Transaxle -
Vehicles With: 4-Speed Automatic
307-01 -32 Transmission
(AW81-40) 307-01 -32
DESCRIPTION AND OPERATION
This is influenced by the following variables:
Engine speed,
Engine load,
Transmission input speed,
Vehicle speed.
The following are actuated:
PCM (torque reduction request signal via the
CAN databus).
Pressure control during gearshifts
In order to ensure that the engagement of the
clutches and brakes is as judder-free as possible,
the main line pressure is reduced during gearshifts.
This is influenced by the following variables:
Enginespeed,
Engine load,
Transmission input speed,
Vehicle speed.
The following are actuated:
Main regulating valve.
Shift timing adaptation during upshifts
In order to ensure that the engagement of the
clutches and brakes is as judder-free as possible,
the timing of the gearshift processes is monitored
during upshifts.
In the event of any discrepancy from the target
values, the main line pressure is adapted
accordingly during the next gearshift.
The shift timing adaptation during upshifts is only
active at transmission fluid temperatures between
50
"C and 120 "C.
This is influenced by the following variables:
Engine load,
Accelerator pedal position,
Transmission input speed,
Vehicle speed,
Transmission fluid temperature,
Selector lever position.
The following are actuated:
Main regulating valve.
Shift timing adaptation during shifts from
3rd to 4th gear
The shift from 3rd gear into 4th gear is the only
gearshift during which a clutch is disengaged and
a brake is engaged simultaneously.
In order to control the synchronized switching of
the two components as exactly as possible, the
shifl timing solenoid valve is actuated accordingly.
In order to ensure that this particular gearshift is
performed as judder-free as possible throughout
the service life of the transmission, the gearshift is
monitored by the two rotational speed sensors and
the actuation of the shift timing solenoid valve is
adapted accordingly.
The shift timing adaptation for gearshifts from 3rd
gear into 4th gear is only active at transmission
fluid temperatures between 30
"C and 120 "C.
This is influenced by the following variables:
Engine load,
Accelerator pedal position,
Transmission input speed,
Vehicle speed,
Transmission fluid temperature,
Selector lever position.
The following are actuated:
Shift timing solenoid valve.
Shift timing adaptation during shifts from
4th to 3rd gear
The shift from 4th gear into 3rd gear is the only
gearshift during which a brake is disengaged and
a clutch is engaged simultaneously.
In order to control the engagement of the clutch as
precisely as possible, the main regulating valve is
actuated accordingly in order to build up the
actuating pressure at exactly the right time.
In order to ensure that this particular gearshift is
performed as judder-free as possible throughout
the service life of the transmission, the gearshift is
monitored by the two rotational speed sensors and
the actuation of the main regulating valve is
adapted accordingly.
The shift timing adaptation for gearshifts from 4th
-
gear into 3rd gear is only active at transmission (
fluid temperatures between 20 "C and 120 "C. .
2006.0 Fiesta 1212006 G380530en
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Automatic Transmission/Transaxle -
Vehicles With: 4Speed Automatic
307-01 -33 Transmission (AW81-40) 307-01 -33
DESCRIPTION AND OPERATION
This is influenced by the following variables: Vehicle
speed,
Engine load, Transmission fluid temperature.
Accelerator pedal position, The following are actuated:
Transmission input speed, SSA shift solenoid valve,
Vehicle speed,
Transmission fluid temperature,
Selector lever position.
The
following are actuated:
Main
regulating valve.
Reverse gear safety strategy
SSB shift solenoid valve.
Torque reduction when pulling away
In order to protect the clutches against excessively
high torque when pulling away, the PCM reduces
the engine torque in response to a request from
the transmission
control.
If the accelerator pedal is depressed while the
The transmission control unit prevents shifts into vehicle is pulling away, then the transmission reverse gear while the vehicle is driving forwards, control unit sends a corresponding signal as otherwise serious transmission damage can be requesting a torque reduction via the CAN databus. caused.
The reverse gear safety strategy is active when This
is influenced by the
following variables:
reverse gear is engaged with the selector lever at ' Selector lever position,
vehicle speeds in excess of 11 kmlh. Accelerator pedal position,
In this
case the transmission control unit actuates ' Engine speed,
the shift timing solenoid valve, as a result of which Transmission input speed,
the actuating pressure does not reach the reverse
. Vehicle speed. gear clutch or the reverse gear brake.
The following are actuated:
The reverse gear safety strategy is deactivated
PCM (torque reduction request signal via the
when the vehicle speed is below 9 kmlh. The
actuating pressure can then reach the reverse gear CAN
databus).
clutch and the reverse gear brake and the gearshift
into reverse gear is performed.
Selector lever positions
This is influenced by the following variables:
Vehicle speed,
Selector lever position.
The
following are actuated:
Shift timing solenoid valve.
Selector lever position "P"
No gear is engaged in selector lever position "P".
The parking
pawl is engaged manually via the
selector lever cable and the selector shaft.
Avoidance of gearshift judder during
engagement of a transmission range Selector
lever position "R"
In order to prevent gearshift judder when moving The reverse gear is eWaged in selector lever
the selector lever from N to D, the transmission position "R.
control unit initially shifts into
2nd gear instead of
1 st gear, and then immediately shifts back into I st
gear before the gearshift process is finished. Selector lever position "N"
This reduces the amount of gearshift judder during No gear is engaged in selector lever position WNW. engagement of a forward drive range.
The powertrain is not blocked. This is influenced by the following variables:
Selector lever position,
Accelerator pedal position,
Transmission input speed,
2006.0 Fiesta 1212006 G380530en
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Automatic Transmission/Transaxle -
Vehicles With: 4Speed Automatic
307-01 -35 Transmission (AW81-40) 307-01 -35
DESCRIPTION AND OPERATION
Engine speed
1 The engine speed is detected by the crankshaft
position (CKP) sensor and passed on to the PCM.
The engine speed is transmitted from the PCM via
the CAN
databus to the transmission control unit.
The transmission control unit uses this signal for:
Torque reduction during gearshifts,
Pressure control during gearshifts.
Engine load
The PCM determines a load signal which is
transmitted via the CAN
databus to the
transmission control unit.
The transmission control unit uses this signal for:
Torque reduction during gearshifts,
Pressure control during gearshifts,
Shift timing adaptation during upshifts,
Shift timing adaptation during shifts from 3rd to
4th gear,
Hill climb mode,
( ' Hill descent mode. ' ,
Torque reduction request signal
Before performing a gearshift, the transmission
control unit sends a signal via the CAN
databus to
the PCM requesting a torque reduction.
The PCM then reduces the engine torque, ensuring
that the gearshift is as smooth and judder-free as
possible.
Brake signal
The PCM receives a signal from the stoplamp
switch when the brake pedal is depressed.
This signal is transmitted via the CAN
databus to
the transmission control unit.
The transmission control unit uses this signal for:
Gearshift control,
Engagement of the TCC
Accelerator pedal position
The PCM receives the current accelerator pedal
position signal from the Accelerator Pedal Position
(APP) sensor.
This signal is transmitted via the CAN
databus to
the transmission control unit.
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,
Avoidance of gearshift judder during
engagement of a transmission range,
Torque reduction when pulling away.
Coolant temperature
The coolant temperature is detected by the Engine
Coolant Temperature (ECT) sensor and passed
on to the PCM.
This signal is transmitted via the CAN
databus to
the transmission control unit.
The transmission control unit uses this signal for:
Cold start mode,
Engagement of the TCC
Selector lever position
The transmission control unit transmits the selector
lever position to the instrument cluster.
The instrument cluster uses the signal to send a
request for a warning tone to the GEM when the
selector lever is not in position "P" and the driver's
door is opened.
-
2006.0 Fiesta 1212006 G380530en
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Automatic TransmissionlTransaxle -
Vehicles With: 4-Speed Automatic
307-01 -37 Transmission
(AW81-40) 307-01 -37
DESCRIPTION AND OPERATION
Sensors
OSS sensor
TSS sensor
The TSS sensor is an inductive pickup.
It measures the transmission input speed via the
outer plate carrier of the
3rdl4th gear clutch and
sends the signal to the transmission control unit.
The transmission control unit uses this signal for:
Torque reduction during gearshifts,
Pressure control during gearshifts,
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,
Avoidance of gearshift judder during
engagement of a transmission range,
Torque reduction when pulling away.
Consequences of signal failure:
No TCC,
no torque reduction,
no shift timing adaptation,
no 4th gear. The
OSS sensor is a Hall sensor.
It is mechanically connected via a gear to the input
wheel of the differential assembly.
It measures the vehicle speed via the input wheel
of the differential assembly and sends the signal
to the transmission control unit.
The transmission control unit uses this signal for:
Gearshift control,
Engagement of the TCC,
Torque reduction during gearshifts,
Pressure control during gearshifts,
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,
Hill climb mode,
Hill descent mode.
2006.0 Fiesta 1212006 G380530en
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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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Automatic Transmission/Transaxle -
Vehicles With: 4Speed Automatic
307-01 -46 Transmission
(AW81-40) 307101 -46
DIAGNOSIS AND TESTING
Symptom Possible Sources Action
PO722 Vehicle speed sensor Vehicle speed sensor (VSS).
1 (vSS) circuit no signal I circuit(+
REFER to WDS.
PO740 Torque converter clutch Lock-up duty solenoid.
solenoid failure
I ~ircuit(s).
REFER to WDS.
REFER to WDS.
PO741 Torque converter clutch
1 (TCC) system.
PO742 Torque converter clutch TCC system stuck on.
I circuit(s).
TCC system stuck off.
REFER to WDS.
PO743 Torque converter clutch Lock-up duty solenoid.
solenoid failure
I circuit(s).
REFER to WDS.
REFER to WDS.
PO727 Engine revolution speed
error
PI 746 Pressure control
I solenoid A open circuit
Powertrain control module
(PCM).
Circuit(s).
I
Line pressure control solenoid.
Circuit(s).
REFER to WDS.
PI 747 Pressure control
solenoid
A short circuit
Line pressure control solenoid.
Circuit(s).
REFER to WDS.
PO972 Shift solenoid A
performance Shift solenoid
A open
circuit.
Circuit(s).
Internal mechanical/hydraulic
failure.
REFER to WDS.
REFER to WDS.
PO974 Shift solenoid A elec- Shift solenoid A.
trical I circuit(!+
PO973 Shift solenoid A elec-
trical
REFER to WDS. Shift solenoid A short circuit.
Circuit(s).
PO975 Shift solenoid B
performance Shift solenoid
B.
Circuit(s).
Internal mechanical/hydraulic
failure.
REFER
to WDS.
PO976 Shift solenoid B Shift solenoid B short circuit.
Circuit(s).
REFER to WDS.
PO977 Shift solenoid B Shift solenoid B open circuit.
Circuit(s).
REFER to WDS.
PO787 Timing solenoid elec- Timing solenoid short circuit.
trical I circuit(s).
REFER to WDS.
REFER to WDS. PO788 Timing solenoid elec-
trical
-- - -
Timing solenoid open circuit.
Circuit(s).
REFER to WDS. PO1 15 Engine coolant signal
error Reported engine failure.
REFER to WDS. I PI 71 9 Engine torque signal
error Reported engine failure.
REFER to WDS. PI 783 Transmission over
temperature condition
2006.0 Fiesta 12/2006 G371498en
Temperature sensor failure.
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Automatic Transmission/Transaxle -
Vehicles With: 4-Speed Automatic
307-01 47 Transmission (AW81-40) 307-01 -47
DIAGNOSIS AND TESTING
Symptom Possible Sources Action
'
U2516 CAN bus off transmit
error
I 5750 Throttle open malfunction 1 . CAN bus. 1. REFER to WDS. I
CAN bus.
U1900 CAN Communication
bus fault error
Line Pressure Test
C1750 Accelerator pedal posi-
tion signal malfunction
. CAN bus.
CAUTIONS:
A Carry out the line pressure test before
carrying out the stall speed test.
If line
pressure is low at idle, do not carry out the
stall speed test or further transaxle damage
will occur.
Accelerator pedal position
sensor.
A Do not maintain wide open throttle (WOT)
in any range for more than five seconds.
REFER to WDS.
A After testing each of the following ranges
ID' (DRIVE) and 'R' (REVERSE)r move the 1. Connect the special tools to the line pressure selector lever to 'N' (NEUTRAL) and run
the engine at
I000 rpm for approximately test point.
i, 1 minute to allow the torque converter to 2. Start the engine and check the line pressures.
cool. Refer to the line pressure chart to determine if -- --- line pressure is within specification. N0TE:Make sure that the self test and electrical 3m If the line pressure is not within specification, repairs have been carried out, or test results may
be incorrect. refer to the
line pressure diagnosis chart.
Line Pressure Chart
Range
Idle Stall
R 0.59 - 0.68 5.88 - 6.76 1.58 - 1.83 15.88 - 18.24
Line Pressure Diagnosis Chart
I I Pressure regulator valve sticking. I
Test Results
Higher than specification in 'D' (DRIVE) and 'R'
(REVERSE)
2006.0 Fiesta 1212006 G371498en
Possible Source
Pressure control solenoid inoperative or open wire
harness.
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