OVERALL SYSTEM
AT-35
D
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BACK-UP CONTROL (ENGINE BRAKE)
If the selector lever is shifted to “2” position while driving in D4 (O/D)
or D
3 , great driving force is applied to the clutch inside the transaxle.
Clutch operating pressure (line pressure) must be increased to deal
with this driving force.
DURING SHIFT CHANGE
The line pressure is temporarily reduced corresponding to a change
in engine torque when shifting gears (that is, when the shift solenoid
valve is switched for clutch operation) to reduce shifting shock.
AT LOW FLUID TEMPERATURE
Fluid viscosity and frictional characteristics of the clutch facing change with fluid temperature. Clutch
engaging or band-contacting pressure is compensated for, according to fluid temperature, to stabilize
shifting quality.
The line pressure is reduced below 60°C (140°F) to prevent
shifting shock due to low viscosity of A/T fluid when temperature
is low.
Line pressure is increased to a maximum irrespective of the
throttle opening when fluid temperature drops to −10°C (14°F).
This pressure rise is adopted to prevent a delay in clutch and
brake operation due to extreme drop of fluid viscosity at low
temperature.
Shift ControlECS00CTD
The shift is regulated entirely by electronic control to accommodate vehicle speed and varying engine opera-
tions. This is accomplished by electrical signals transmitted by the revolution sensor and the ECM (accelerator
pedal position sensor). This results in improved acceleration performance and fuel economy.
SAT004J
SAT005J
SAT006J
SAT007J
AT-36
OVERALL SYSTEM
CONTROL OF SHIFT SOLENOID VALVES A AND B
The TCM activates shift solenoid valves A and B according to sig-
nals from the throttle position sensor and revolution sensor to select
the optimum gear position on the basis of the shift schedule memo-
rized in the TCM.
The shift solenoid valve performs simple ON-OFF operation. When
set to “ON”, the drain circuit closes and pilot pressure is applied to
the shift valve.
RELATION BETWEEN SHIFT SOLENOID VALVES A AND B GEAR POSITIONS
CONTROL OF SHIFT VALVES A AND B
Pilot pressure generated by the operation of shift solenoid valves A and B is applied to the end face of shift
valves A and B.
The drawing above shows the operation of shift valve B. When the shift solenoid valve is “ON”, pilot pressure
applied to the end face of the shift valve overcomes spring force, moving the valve upward.
Lock-Up ControlECS00CTE
The torque converter clutch piston in the torque converter is locked to eliminate torque converter slip to
increase power transmission efficiency. The solenoid valve is controlled by an ON-OFF duty signal sent from
the TCM. The signal is converted to an oil pressure signal which controls the torque converter clutch piston.
CONDITIONS FOR LOCK-UP OPERATION
When vehicle is driven in 3rd and 4th gear position, vehicle speed and throttle opening are detected. If the
detected values fall within the lock-up zone memorized in the TCM, lock-up is performed.
SAT008J
Shift solenoid valveGear position
D1 , 21 , 11D2 , 22 , 12D3D4 (O/D) N-P
A ON (Closed) OFF (Open) OFF (Open) ON (Closed) ON (Closed)
B ON (Closed) ON (Closed) OFF (Open) OFF (Open) ON (Closed)
SAT009J
Overdrive control switch ON OFF
Selector lever “D” position
Gear position D
4D3
Vehicle speed sensor More than set value
Throttle position sensor Less than set opening
Closed throttle position switch OFF
A/T fluid temperature sensor More than 40°C (104°F)
AT-40
[EURO-OBD]
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
[EURO-OBD]ON BOARD DIAGNOSTIC SYSTEM DESCRIPTIONPFP:00000
IntroductionECS004QH
The A/T system has two self-diagnostic systems.
The first is the emission-related on board diagnostic system (EURO-OBD) performed by the TCM in combina-
tion with the ECM. The malfunction is indicated by the MI (malfunction indicator) and is stored as a DTC in the
ECM memory but not the TCM memory.
The second is the TCM original self-diagnosis indicated by the O/D OFF indicator lamp. The malfunction is
stored in the TCM memory. The detected items are overlapped with EURO-OBD self-diagnostic items. For
detail, refer to AT- 4 5 , "
SELF-DIAGNOSTIC RESULT TEST MODE" .
EURO-OBD Function for A/T SystemECS004QI
The ECM provides emission-related on board diagnostic (EURO-OBD) functions for the A/T system. One
function is to receive a signal from the TCM used with EURO-OBD-related parts of the A/T system. The signal
is sent to the ECM when a malfunction occurs in the corresponding EURO-OBD-related part. The other func-
tion is to indicate a diagnostic result by means of the MI (malfunction indicator) on the instrument panel. Sen-
sors, switches and solenoid valves are used as sensing elements.
The MI automatically illuminates in One or Two Trip Detection Logic when a malfunction is sensed in relation
to A/T system parts.
One or Two Trip Detection Logic of EURO-OBDECS004QJ
ONE TRIP DETECTION LOGIC
If a malfunction is sensed during the first test drive, the MI will illuminate and the malfunction will be stored in
the ECM memory as a DTC. The TCM is not provided with such a memory function.
TWO TRIP DETECTION LOGIC
When a malfunction is sensed during the first test drive, it is stored in the ECM memory as a 1st trip DTC
(diagnostic trouble code) or 1st trip freeze frame data. At this point, the MI will not illuminate. — First Trip
If the same malfunction as that experienced during the first test drive is sensed during the second test drive,
the MI will illuminate. — Second Trip
A/T-related parts for which the MI illuminates during the first or second test drive are listed below.
The “trip” in the “One or Two Trip Detection Logic” means a driving mode in which self-diagnosis is performed
during vehicle operation.
EURO-OBD Diagnostic Trouble Code (DTC)ECS004QK
HOW TO READ DTC AND 1ST TRIP DTC
DTC and 1st trip DTC can be read by the following methods.
( With CONSULT-II or GST) CONSULT-II or GST (Generic Scan Tool) Examples: P0705, P0710,
P0720, P0725, etc.
These DTCs are prescribed by SAE J2012.
(CONSULT-II also displays the malfunctioning component or system.)
1st trip DTC No. is the same as DTC No.
Output of the diagnostic trouble code indicates that the indicated circuit has a malfunction. How-
ever, in case of the Mode II and GST they do not indicate whether the malfunction is still occurring
or occurred in the past and returned to normal.
CONSULT-II can identify them as shown below. Therefore, using CONSULT-II (if available) is rec-
ommended.
ItemsMI
One trip detection Two trip detection
Shift solenoid valve A — DTC: P0750 X
Shift solenoid valve B — DTC: P0755 X
Throttle position sensor — DTC: P1705 X
Except aboveX
AT-44
[EURO-OBD]
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
Malfunction Indicator (MI)ECS004QL
1. The malfunction indicator will light up when the ignition switch is
turned ON without the engine running. This is for checking the
lamp.
If the malfunction indicator does not light up, refer to DI-35,
"Schematic" .
(Or see MI & CONSULT-II in EC section. Refer to EC-64,
"Malfunction Indicator (MI)" (WITH EURO-OBD) or EC-568,
"Malfunction Indicator (MI)" (WITHOUT EURO-OBD) or EC-
103, "CONSULT-II Function (ENGINE)" (WITH EURO-OBD)
or EC-604, "
CONSULT-II Function (ENGINE)" (WITHOUT
EURO-OBD).
2. When the engine is started, the malfunction indicator should go
off.
If the lamp remains on, the on board diagnostic system has detected an emission-related (EURO-OBD)
malfunction. For detail, refer to EC-52, "
ON BOARD DIAGNOSTIC (OBD) SYSTEM" .
CONSULT-IIECS004QM
After performing “SELF-DIAGNOSTIC PROCEDURE (WITH CONSULT-II)” AT- 4 5 , place check marks for
results on the “DIAGNOSTIC WORKSHEET”, AT- 5 8
. Reference pages are provided following the items.
NOTICE:
1. The CONSULT-II electrically displays shift timing and lock-up timing (that is, operation timing of each sole-
noid).
Check for time difference between actual shift timing and the CONSULT-II display. If the difference is
noticeable, mechanical parts (except solenoids, sensors, etc.) may be malfunctioning. Check mechanical
parts using applicable diagnostic procedures.
2. Shift schedule (which implies gear position) displayed on CONSULT-II and that indicated in Service Man-
ual may differ slightly. This occurs because of the following reasons:
–Actual shift schedule has more or less tolerance or allowance,
–Shift schedule indicated in Service Manual refers to the point where shifts start, and
–Gear position displayed on CONSULT-II indicates the point where shifts are completed.
3. Shift solenoid valve “A” or “B” is displayed on CONSULT-II at the start of shifting. Gear position is dis-
played upon completion of shifting (which is computed by TCM).
4. Additional CONSULT-II information can be found in the Operation Manual supplied with the CONSULT-II
unit.
FUNCTION
SAT652J
Diagnostic test mode Function Reference page
Work supportThis mode enables a technician to adjust some devices faster and more accurately by
following the indications on CONSULT-II.—
Self-diagnostic results Self-diagnostic results can be read and erased quickly.AT- 4 5
Data monitor Input/Output data in the ECM can be read.AT- 4 6
CAN diagnostic support
monitorThe results of transmit/receive diagnosis of CAN communication can be read. —
Function testConducted by CONSULT-II instead of a technician to determine whether each system
is “OK” or “NG”.—
DTC work support Select the operating condition to confirm Diagnosis Trouble Codes.AT- 4 7
TCM part number TCM part number can be read. —
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
AT-45
[EURO-OBD]
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SELF-DIAGNOSTIC PROCEDURE (WITH CONSULT-II)
1. Turn on CONSULT-II and touch “ENGINE” for EURO-OBD
detected items or touch “A/T” for TCM self-diagnosis.
If A/T is not displayed, check TCM power supply and ground cir-
cuit. Refer to AT- 9 4 , "
TCM Terminals and Reference Value" . If
result is NG, refer to PG-2, "
POWER SUPPLY ROUTING" .
2. Touch “SELF DIAGNOSIS”.
Display shows malfunction experienced since the last erasing
operation.
CONSULT-II performs “real time diagnosis”.
Also, any malfunction detected while in this mode will be dis-
played at real time.
SELF-DIAGNOSTIC RESULT TEST MODE
SAT014K
SAT987J
Items (CONSULT-II screen terms) Malfunction is detected when... EURO-OBD (DTC)
CAN COMM CIRCUIT
Malfunction is detected in CAN communication line. U1000
VHCL SPEED SEN·A/T
TCM does not receive the proper voltage signal from the sensor.P0720
VHCL SPEED SEN·MTR—
THROTTLE POSI SEN
TCM receives an excessively low or high voltage from this sensor P1705
SHIFT SOLENOID/V A
TCM detects an improper voltage drop when it tries to operate the sole-
noid valve.P0750
SHIFT SOLENOID/V B
TCM detects an improper voltage drop when it tries to operate the sole-
noid valve.P0755
OVERRUN CLUTCH S/V
TCM detects an improper voltage drop when it tries to operate the sole-
noid valve.P1760
T/C CLUTCH SOL/V
TCM detects an improper voltage drop when it tries to operate the sole-
noid valve.P0740
ATF TEMP SEN/CIRC
TCM receives an excessively low or high voltage from the sensor.P0710
BATT/FLUID TEMP SEN—
ENGINE SPEED SIG
TCM does not receive the proper voltage signal from the ECM. P0725
A/T 1ST GR FNCTN
A/T cannot be shifted to the 1st gear position even if electrical circuit is
good.P0731*1
A/T 2ND GR FNCTN
A/T cannot be shifted to the 2nd gear position even if electrical circuit is
good.P0732*1
A/T 3RD GR FNCTN
A/T cannot be shifted to the 3rd gear position even if electrical circuit is
good.P0733*1
A/T 4TH GR FNCTN
A/T cannot be shifted to the 4th gear position even if electrical circuit is
good.P0734*1
LINE PRESSURE S/V
TCM detects an improper voltage drop when it tries to operate the sole-
noid valve.P0745
CONTROL UNIT (RAM)
TCM memory (RAM) is malfunctioning —
CONTROL UNIT (ROM)
TCM memory (ROM) is malfunctioning —
AT-46
[EURO-OBD]
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
*1: These malfunctions cannot be displayed by MI if another malfunction is assigned to lamp MI.
DATA MONITOR MODE (A/T)
X: Standard, —: Not applicable, : Option CONT UNIT(EEP ROM)
TCM memory (EEP ROM) is malfunctioning. —
PNP SW/CIRC
TCM does not receive the correct voltage signal (based on the gear
position) from the switch.P0705
INITIAL START
This is not a malfunction message (Whenever shutting off a power sup-
ply to the TCM, this message appears on the screen).—
No failure
(NO SELF DIAGNOSTIC FAILURE
INDICATED FURTHER TESTING
MAY BE REQUIRED)
No failure has been detected. — Items (CONSULT-II screen terms) Malfunction is detected when... EURO-OBD (DTC)
Monitor item (Unit)SELECT MONITOR ITEM
Remarks
TCM INPUT
SIGNALSMAIN SIG-
NALSSELEC-
TION FROM
MENU
VHCL/S SE·A/T (km/h) X — Revolution sensor
VHCL/S SE·MTR (km/h) X —Vehicle speed display may not be accu-
rate under approx. 10 km/h (6 mph). It
may not indicate 0 km/h (0 mph) when
vehicle is stationary.
THRTL POS SEN (V) X —
FLUID TEMP SE (V) X —
BATTERY VOLT (V) X —
ENGINE SPEED (rpm) X X
TURBINE REV (rpm) X —
OVERDRIVE SW (ON/OFF) X —
PN POSI SW (ON/OFF) X —
R POSITION SW (ON/OFF) X —
D POSITION SW (ON/OFF) X —
2 POSITION SW (ON/OFF) X —
1 POSITION SW (ON/OFF) X —
ASCD·CRUISE (ON/OFF) X —
Signal input with CAN communication.
ACC OD CUT (ON/OFF) X —
KICKDOWN SW (ON/OFF) X —
Not mounted but displayed.
POWERSHIFT SW (ON/OFF) X —
CLOSED THL/SW (ON/OFF) X —
Signal input with CAN communication.
W/O THRL/P-SW (ON/OFF) X —
*SHIFT S/V A (ON/OFF) — —
Displays status of check signal (reinput
signal) for TCM control signal output.
Remains unchanged when solenoid
valves are open or shorted. *SHIFT S/V B (ON/OFF) — —
*OVERRUN/C S/V (ON/OFF) — —
HOLD SW (ON/OFF) X — Not mounted but displayed.
BRAKE SW (ON/OFF) X — Stop lamp switch
AT-54
[EURO-OBD]
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
JUDGEMENT OF SELF-DIAGNOSIS CODE
O/D OFF indicator lamp
All judgement flickers are the same.
All circuits that can be confirmed by self-diagnosis are OK.1st judgement flicker is longer than others.
Revolution sensor circuit is short-circuited or disconnected.
Go to DTC P0720 VEHICLE SPEED SENSOR·A/T (REVOLU-
TION SENSOR).
Refer to AT- 11 2
2nd judgement flicker is longer than others.
Vehicle speed sensor circuit is short-circuited or disconnected.
Go to DTC VEHICLE SPEED SENSOR·MTR.
Refer to AT-1923rd judgement flicker is longer than others.
Accelerator pedal position (APP) sensor circuit is short-circuited
or disconnected.
Go to DTC P1705 ACCELERATOR PEDAL POSITION (APP)
SENSOR.
Refer to AT- 1 7 3
4th judgement flicker is longer than others.
Shift solenoid valve A circuit is short-circuited or disconnected.
Go to DTC P0750 SHIFT SOLENOID VALVE A.
Refer to AT-1615th judgement flicker is longer than others.
Shift solenoid valve B circuit is short-circuited or disconnected.
Go to DTC P0755 SHIFT SOLENOID VALVE B.
Refer to AT- 1 6 7
SCIA4672ESCIA5591E
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ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
AT-55
[EURO-OBD]
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6th judgement flicker is longer than others.
Overrun clutch solenoid valve circuit is short-circuited or discon-
nected.
Go to DTC P1760 OVERRUN CLUTCH SOLENOID VALVE.
Refer to AT- 1 7 87th judgement flicker is longer than others.
Torque converter clutch solenoid valve circuit is short-circuited or
disconnected.
Go to DTC P0740 TORQUE CONVERTER CLUTCH SOLE-
NOID VALVE.
Refer to AT-148
8th judgement flicker is longer than others.
A/T fluid temperature sensor is disconnected or TCM power sup-
ply circuit is damaged.
Go to DTC BATT/FLUID TEMP SEN (A/T FLUID TEMP SEN-
SOR CIRCUIT AND TCM POWER SOURCE).
Refer to AT-1849th judgement flicker is longer than others.
Engine speed signal circuit is short-circuited or disconnected.
Go to DTC P0725 ENGINE SPEED SIGNAL.
Refer to AT- 11 9
O/D OFF indicator lamp
SCIA5596ESCIA5597E
SCIA5598ESCIA5599E