A/T CONTROL SYSTEM
AT-27
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TCM FunctionECS00FWI
The function of the TCM is to:
lReceive input signals sent from various switches and sensors.
lDetermine required line pressure, shifting point, lock-up operation, and engine brake operation.
lSend required output signals to the respective solenoids.
CONTROL SYSTEM OUTLINE
The A/T senses vehicle operating conditions through various sensors or signals. It always controls the opti-
mum shift position and reduces shifting and lock-up shocks.
CONTROL SYSTEM DIAGRAM
SENSORS (or SIGNALS)
TCM
ACTUATORS
PNP switch
Accelerator pedal position signal
Closed throttle position signal
Wide open throttle position signal
Engine speed signal
A/T fluid temperature sensor
Revolution sensor
Vehicle speed signal
1st position switch signal
Overdrive control switch signal
Stop lamp switch signal
Turbine revolution sensor
ATF pressure switchShift control
Line pressure control
Lock-up control
Engine brake control
Timing control
Fail-safe control
Self-diagnosis
CONSULT-II communication line
Duet-EA control
CAN systemInput clutch solenoid valve
Direct clutch solenoid valve
Front brake solenoid valve
High and low reverse clutch solenoid
valve
Low coast brake solenoid valve
Torque converter clutch solenoid valve
Line pressure solenoid valve
OD OFF indicator lamp
Starter relay
Back-up lamp relay
SCIA7332E
AT-28
A/T CONTROL SYSTEM
CAN Communication
ECS00FWJ
SYSTEM DESCRIPTION
CAN (Controller Area Network) is a serial communication line for real time application. It is an on-vehicle mul-
tiplex communication line with high data communication speed and excellent error detection ability. Many elec-
tronic control units are equipped onto a vehicle, and each control unit shares information and links with other
control units during operation (not independent). In CAN communication, control units are connected with 2
communication lines (CAN H line, CAN L line) allowing a high rate of information transmission with less wiring.
Each control unit transmits/receives data but selectively reads required data only. For details, refer toLAN-30,
"CAN Communication Unit".
Input/Output Signal of TCMECS00FWK
*1: Spare for vehicle speed sensor·A/T (revolution sensor)
*2: Spare for accelerator pedal position signal
*3: If these input and output signals are different, the TCM triggers the fail-safe function.
*4: Used as a condition for starting self-diagnosis; if self-diagnosis are not started, it is judged that there is some kind of error.
*5: Input by CAN communications.
*6: Output by CAN communications.Control itemLine
pressure
controlVehicle
speed
controlShift
controlLock-up
controlEngine
brake
controlFail-safe
function
(*3)Self-diag-
nostics
function
InputAccelerator pedal position signal
(*5)XXXXXX X
Vehicle speed sensor A/T
(revolution sensor)XXXXXX X
Vehicle speed sensor MTR
(*1) (*5)X
Closed throttle position signal
(*5)X(*2) X X X X(*4)
Wide open throttle position signal
(*5)XX(*4)
Turbine revolution sensor 1 X X X X X
Turbine revolution sensor 2
(for 4th speed only)XXXXX
Engine speed signals
(*5)XXXXXX X
Stop lamp switch signal
(*5)XXX X(*4)
A/T fluid temperature sensors 1, 2 X X X X X X
ASCDOperation signal
(*5)XXX
Overdrive cancel signal
(*5)X
OutputDirect clutch solenoid
(ATF pressure switch 5)XX X X
Input clutch solenoid
(ATF pressure switch 3)XX X X
High and low reverse clutch solenoid
(ATF pressure switch 6)XX X X
Front brake solenoid
(ATF pressure switch 1)XX X X
Low coast brake solenoid
(ATF pressure switch 2)XX XX X
Line pressure solenoid X X X X X X X
TCC solenoid X X X
Self-diagnosis table
(*6)X
Starter relayXX
AT-34
TROUBLE DIAGNOSIS
TROUBLE DIAGNOSIS
PFP:00004
DTC Inspection Priority ChartECS00FWV
If some DTCs are displayed at the same time, perform inspections one by one based on the following priority
chart.
NOTE:
If DTC “U1000 CAN COMM CIRCUIT” is displayed with other DTCs, first perform the trouble diagnosis
for “DTC U1000 CAN COMMUNICATION LINE”. Refer toAT-91
.
Fail-safeECS00FWW
The TCM has an electrical fail-safe mode. This mode makes it possible to operate even if there is an error in a
main electronic control input/output signal circuit. In fail-safe mode A/T is fixed in 2nd, 4th or 5th (depending
on the breakdown position), so the customer should feel “slipping” or “poor acceleration”.
Even when the electronic circuits are normal, under special conditions (for example, when slamming on the
brake with the wheels spinning drastically and stopping the tire rotation), the transmission can go into fail-safe
mode. If this happens, switch OFF the ignition switch for 10 seconds, then switch it ON again to return to the
normal shift pattern. Therefore, the customer's vehicle has returned to normal, so handle according toAT- 3 7 ,
"WORK FLOW".
FAIL-SAFE FUNCTION
If any malfunction occurs in a sensor or solenoid, this function controls the A/T to mark driving possible.
Vehicle Speed Sensor
Signals are input from two systems - from vehicle speed sensor A/T (revolution sensor) installed on the A/T
and from combination meter so normal driving is possible even if there is a malfunction in one of the systems.
And if vehicle speed sensor A/T (revolution sensor) has unusual cases, 5th gear is prohibited.
Accelerator Pedal Position Sensor
If there is a malfunction in one of the systems, the accelerator opening angle is controlled by ECM according
to a pre-determined accelerator angle to make driving possible. And if there are malfunctions in tow systems,
the engine speed is fixed by ECM to a pre-determined engine speed to make driving possible.
PNP Switch
In the unlikely event that a malfunction signal enters the TCM, the position indicator is switched OFF, the
starter relay is switched OFF (starter starting is disabled), the back-up lamp relay switched OFF (back-up lamp
is OFF) and the position is fixed to the “D” position to make driving possible.
Starter Relay
The starter relay is switched OFF. (Starter starting is disabled.)
Priority Detected items (DTC)
1 U1000 CAN communication line
2 Except above
AT-46
TROUBLE DIAGNOSIS
ROAD TEST
Description
lThe road test inspects overall performance of A/T and analyzes possible malfunction causes.
lThe road test is perform in the following three stages.
1. Check before engine is started. Refer toAT-46
.
2. Check at idle. Refer toAT-47
.
3. Cruise test.
lInspect all the items from Part 1 to Part 3. Refer toAT-48,AT-50,AT-51.
lBefore beginning the road test, check the test procedure and inspection items.
lTest all inspection items until the symptom is uncovered. Diagnose NG items when all road tests are com-
plete.
CheckBeforeEngineIsStartedECS00FX1
1.CHECK OD OFF INDICATOR LAMP
1. Park vehicle on level surface.
2. Move selector lever to “P” position.
3. Turn ignition switch OFF and wait at least 10 seconds.
4. Turn ignition switch ON. (Do not start engine.)
Does OD OFF indicator lamp light up for about 2 seconds?
YES >> 1. Turn ignition switch OFF.
2. Perform self-diagnosis and record all NG items onAT-38, "
DIAGNOSTIC WORKSHEET".
Refer toAT-80, "
SELF-DIAGNOSTIC RESULT MODE",AT-89, "TCM SELF-DIAGNOSTIC
PROCEDURE (WITHOUT CONSULT-II)".
3. Go toAT-47, "
Check at Idle".
NO >> Stop the road test and go toAT- 1 7 7 , "
OD OFF Indicator Lamp Does Not Come On".
Stall speedOil pressure does not
rise higher than the oil
pressure for idle.Possible causes include a sensor malfunction or malfunction in the pressure adjustment
function.
For example
lAccelerator pedal position signal malfunction
lTCM malfunction
lLine pressure solenoid malfunction (shorting, sticking in ON state)
lPressure regulator valve or plug sticking
lPilot valve sticking or pilot filter clogged
The pressure rises, but
does not enter the stan-
dard position.Possible causes include malfunctions in the pressure supply system and malfunction in the
pressure adjustment function.
For example
lAccelerator pedal position signal malfunction
lLine pressure solenoid malfunction (sticking, filter clog)
lPressure regulator valve or plug sticking
lPilot valve sticking or pilot filter clogged
Only low for a specific
positionPossible causes include an oil pressure leak in a passage or device related to the position
after the pressure is distributed by the manual valve. Judgement Possible cause
TROUBLE DIAGNOSIS
AT-47
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Check at IdleECS00FX2
1.CHECK STARTING THE ENGINE
1. Park vehicle on level surface.
2. Move selector lever to “P” or “N” position.
3. Turn ignition switch OFF.
4. Start engine.
Does the engine start?
YES >> GO TO 2.
NO >> Stop the road test and go toAT- 1 7 7 , "
Engine Cannot Be Started in“P”or“N”Position".
2.CHECK STARTING THE ENGINE
1. Turn ignition switch ON.
2. Move selector lever in “D”, “3”, “2”, “1” or “R” position.
3. Start engine.
Does the engine start in any positions?
YES >> Stop the road test and go toAT- 1 7 7 , "Engine Cannot Be Started in“P”or“N”Position".
NO >> GO TO 3.
3.CHECK “P” POSITION FUNCTIONS
1. Move selector lever to “P” position.
2. Turn ignition switch OFF.
3. Release the parking brake.
4. Push the vehicle forward or backward.
5. Engage the parking brake.
When you push the vehicle with the parking brake released, does it move?
YES >> Enter a check mark at “In “P” Position Vehicle Moves When Pushed” onAT-38, "DIAGNOSTIC
WORKSHEET", then continue the road test.
NO >> GO TO 4.
4.CHECK “N” POSITION FUNCTIONS
1. Start engine.
2. Move selector lever to “N” position.
3. Release the parking brake.
Does vehicle move forward or backward?
YES >> Enter a check mark at “In “N” Position Vehicle Moves” onAT-38, "DIAGNOSTIC WORKSHEET",
then continue the road test.
NO >> GO TO 5.
5.CHECK SHIFT SHOCK
1. Engage the brake.
2. Move selector lever to “D” position.
When the A/T is shifted from
“N”to“D”, is there an excessive shock?
YES >> Enter a check mark at “Large Shock (“N” to “D” Position)” onAT-38, "DIAGNOSTIC WORK-
SHEET"the diagnosis worksheet, then continue the road test.
NO >> GO TO 6.
AT-50
TROUBLE DIAGNOSIS
8.CHECK LOCK-UP RELEASE
Check lock-up cancellation by depressing brake pedal lightly to decelerate.
With CONSULT-II
Select “TCC SOLENOID” with “MAIN SIGNALS” mode for “A/T”. Refer toAT-77, "
CONSULT-II REFERENCE
VA L U E".
Does lock-up cancel?
YES >> GO TO 9.
NO >> Enter a check mark at “Lock-up Is Not Released” onAT-38, "
DIAGNOSTIC WORKSHEET",then
continue the road test.
9.CHECK SHIFT-DOWN D5®D4
Decelerate by pressing lightly on brake pedal.
With CONSULT-II
Read the gear position and engine speed. Refer toAT-83, "
DATA MONITOR MODE".
When the A/T shift-down D
5®D4, does the engine speed drop smoothly back to idle?
YES >> 1. Stop the vehicle.
2. Go toAT-50, "
Cruise Test - Part 2".
NO >> Enter a check mark at “Engine Speed Does Not Return to Idle” onAT-38, "
DIAGNOSTIC WORK-
SHEET", then continue the road test. Go toAT-50, "Cruise Test - Part 2".
CruiseTest-Part2ECS00FX4
1.CHECK STARTING FROM D1
1. Move selector lever to “D” position.
2. Accelerate at half throttle.
With CONSULT-II
Read the gear position. Refer toAT-83, "
DATA MONITOR MODE".
Does it start from D
1?
YES >> GO TO 2.
NO >> Enter a check mark at “Vehicle Cannot Be Started from D
1”onAT-38, "DIAGNOSTIC WORK-
SHEET", then continue the road test.
2.CHECK SHIFT-UP D1®D2
Press accelerator pedal down all the way and inspect whether or not the A/T shifts up (D1®D2)atthecor-
rect speed. Refer toAT-52, "
Vehicle Speed at Which Gear Shifting Occurs".
With CONSULT-II
Read the gear position, throttle degree and vehicle speed. Refer toAT-83, "
DATA MONITOR MODE".
Does the A/T shift-up D
1®D2at the correct speed?
YES >> GO TO 3.
NO >> Enter a check mark at “A/T Does Not Shift: D
1®D2”onAT-38, "DIAGNOSTIC WORKSHEET",
then continue the road test.
3.CHECK SHIFT-UP D2®D3
Press accelerator pedal down all the way and inspect whether or not the A/T shifts up (D2®D3)atthecor-
rect speed. Refer toAT-52, "
Vehicle Speed at Which Gear Shifting Occurs".
With CONSULT-II
Read the gear position, throttle degree and vehicle speed. Refer toAT-83, "
DATA MONITOR MODE".
Does the A/T shift-up D
2®D3at the correct speed?
YES >> GO TO 4.
NO >> Enter a check mark at “A/T Does Not Shift: D
2®D3”onAT-38, "DIAGNOSTIC WORKSHEET",
then continue the road test.
TROUBLE DIAGNOSIS
AT-87
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3. Touch select item menu.
4. Touch “START”.
5. Perform driving test according to “DTC Confirmation Procedure”
in “TROUBLE DIAGNOSIS FOR DTC”.
lWhen testing conditions are satisfied, CONSULT-II screen
changes from “OUT OF CONDITION” to “TESTING”.
6. Stop vehicle.
SCIA7151E
SCIA7152E
SCIA5160E
SCIA5161E
SCIA5164E
TROUBLE DIAGNOSIS
AT-89
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Diagnostic Procedure Without CONSULT-IIECS00FXB
TCM SELF-DIAGNOSTIC PROCEDURE (WITHOUT CONSULT-II)
Description
In the unlikely event of a malfunction in the electrical system, when the ignition switch is switched ON, the OD
OFF indicator lamp lights up for 2 seconds. If there is no malfunction, when the ignition switch is turned ON,
the indicator lamp lights up for 2 seconds. As a method for locating the suspect circuit, when the self-diagnos-
tics start signal is input, the memory for the malfunction location is output and OD OFF indicator lamp flashes
to display the corresponding DTC.
Diagnostic Procedure
1.CHECK OD OFF INDICATOR LAMP
1. Start the engine with selector lever in “P” position. Warm engine to normal operating temperature.
2. Turn ignition switch ON and OFF at least twice, then leave it in the OFF position.
3. Wait 10 seconds.
4. Turn ignition switch ON. (Do not start engine.)
Does OD OFF indicator lamp come on for about 2 seconds?
YES >> GO TO 2.
NO >> GO TOAT- 1 7 7 , "
OD OFF Indicator Lamp Does Not Come On".
2.JUDGEMENT PROCEDURE
1. Turn ignition switch OFF.
2. Keep pressing shift lock release button.
3. Move selector lever from “P” to “D” position.
4. Release accelerator pedal. (Set the closed throttle position signal ON.)
5. Depress brake pedal. (Stop lamp switch signal ON.)
6. Turn ignition switch ON.
7. Wait 3 seconds.
8. Move selector lever from “D” to “3” position.
9. Release brake pedal. (Stop lamp switch signal OFF.)
10. Move selector lever from “3” to “2” position.
11. Depress brake pedal. (Stop lamp switch signal ON.)
12. Release brake pedal. (Stop lamp switch signal OFF.)
13. Depress accelerator pedal fully and release it.
>> GO TO 3.
3.CHECK SELF-DIAGNOSIS CODE
Check OD OFF indicator lamp. Refer toAT-90, "
Judgement Self-diagnosis Code".
If the system does not go into self-diagnosis. Refer toAT-99, "
DTC P0705 PARK/NEUTRAL POSITION
SWITCH",AT- 1 6 8 , "CLOSED THROTTLE POSITION AND WIDE OPEN THROTTLE POSITION CIRCUIT",
AT- 1 6 9 , "
BRAKE SIGNAL CIRCUIT".
>>DIAGNOSIS END