2007 FORD FIESTA transmission fluid

Automatic Transmission/Transaxle -
Vehicles With: 4-Speed Automatic
Transmission (AW81-40)
DESCRIPTION AND OPERATION
Item Description
1 5 1 Generic Electronic Module (GEM) I
I
1 6 1 Turbine Shaft Speed (TSS) sensor I
1 7 1 Output Shaft Speed (OSS) sensor I
1
2
3
4
l tem Description
Transmission control unit
Data Link Connector (DLC)
Powertrain Control Module (PCM)
Instrument cluster
1 8 I Transmission Range (TR) sensor I
1 9 1 Starter inhibit relay I
1 10 1 Backup lamp relay I
11 Transmission Fluid Temperature (TFT)
I I sensor
1 12 loverdrive switch I
1 13 1 Driver's side door ajar switch I
1 14 1 Solenoid valves in the main control body 1
Transmission control unit
Item Description
Electrical connector, vehicle wiring
harness
connector, transmission wiring
harness
--
The transmission control unit is located in the
'engine compartment on the left-hand side member.
The transmission control unit evaluates incoming
signals and controls the actuators accordingly.
2006.0 Fiesta 1212006 G380530en
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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: 4-Speed Automatic
307-01 -36 Transmission (AW81-40) 307-01 -36
DESCRIPTION AND OPERATION
Actuation of the MIL warning lamp Warning tone request
The information required to actuate the
MIL The
driver's door is open.
warning lamp is sent the transmission control The instrument cluster passes on the warning tone unit to the instrument cluster.
request to the GEM. The GEM generates the
warning tone.
I I I
Actuation of the overdrive indicator lamp
I
The overdrive indicator lamp is located on the
instrument panel.
The MIL warning lamp
is actuated by the The transmission control unit sends
a warning tone
instrument cluster if there are serious faults in the request
to the instrument cluster if the following
transmission control or if the transmission fluid conditions are
met:
temperature is excessively high.
The selector lever is not in position "P",
The information required to actuate the overdrive
indicator lamp is sent from the transmission control
unit when the overdrive switch on the selector lever
is pressed.
2006.0 Fiesta 1u2oos G380530en
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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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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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Automatic TransmissionlTransaxle -
Vehicles With: 4-Speed Automatic
307-01 -48 Transmission (AW81-40) 307-01 -48
DIAGNOSIS AND TESTING
Stall Speed Test
This test checks the operation of the following
components:
1
Test Results
Lower than specification in 'Dl (DRIVE) and 'R'
(REVERSE)
Lower than specification in
'Dl (DRIVE)
Lower than specification in
'R' (REVERSE)
torque converter
forward clutch
low one way clutch assembly
engine performance
Possible Source
Pressure control solenoid inoperative or open wire
harness.
Pressure regulator valve sticking.
Worn oil pump.
Oil strainer blocked.
Fluid leak from each clutch hydraulic circuit.
Drive hydraulic circuit failure.
Forward clutch failure.
Reverse hydraulic circuit failure. Reverse clutch failure.
First and reverse brake failure.
WARNINGS:
A Do not maintain wide open throttle (WOT)
in any range for more than five seconds.
A If the engine speed (rpm) recorded by the
tachometer exceeds maximum specified
rpm, release the accelerator pedal
immediately. Clutch or band slippage is
indicated.
N0TE:The stall speed test should be carried out
with the engine and transaxle at normal operating
temperatures (50°C to 80°C).
A Apply the parking brake firmly while N0TE:Prolonged use of this procedure may set
carrying out each stall test. DTC PO71 2. After carrying out the stall speed test,
A Apply the foot brake firmly while carrying run the OBD test and clear the DTCs.
out each stall test. I. Connect a tachometer to the engine.
CAUTIONS:
A Always carry out the line pressure test
before carrying out the stall speed test. If
the line pressure is low at idle, do not carry
out the stall speed test or further transaxle
damage will occur.
A After testing each of the following ranges
'D'
(DRIVE) and 'R' (REVERSE), move the
selector lever to
'N' (NEUTRAL) and run
the engine at 1000 rpm for approximately
one minute to allow the torque converter
to cool.
2. Press the accelerator pedal to the floor WOT in
each selected range. Record the rpm reached
in each selected range and refer to the stall
speed chart.
3. If the stall speed is not within specification, refer
to the stall speed diagnosis chart.
Stall S~eed Chart
I Engine 1.6L I Speed (rpm) I
I 'Dl (DRIVE) I 2500 2 150 1
'R' (REVERSE) 2420 +, 150 -
Stall
Speed Diagnosis Chart
2006.0 Fiesta 1212006 G371498en
Test Results
Lower than specification in ID' (DRIVE) and 'R'
(REVERSE)
Possible Source
Low engine power.
Torque converter one-way clutch failure.
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