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
TROUBLE DIAGNOSIS
AT-35
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A/T Interlock
lIf there is an A/T interlock judgment malfunction, the A/T is fixed in 2nd gear to make driving possible.
NOTE:
When the vehicle is driven fixed in 2nd gear, a turbine revolution sensor malfunction is displayed,
but this is not a turbine revolution sensor malfunction.
lWhen the coupling pattern below is detected, the fail-safe action corresponding to the pattern is per-
formed.
A/T INTERLOCK COUPLING PATTERN TABLE
l:NG X:OK
A/T 1st Engine Braking
When there is an A/T first gear engine brake judgment malfunction, the low coast brake solenoid is switched
OFF to avoid the engine brake operation.
Line Pressure Solenoid
The solenoid is switched OFF and the line pressure is set to the maximum hydraulic pressure to make driving
possible.
Torque Converter Clutch Solenoid
The solenoid is switched OFF to release the lock-up.
Low Coast Brake Solenoid
When a malfunction (electrical or functional) occurs, in order to make driving possible. If the solenoid is ON,
the A/T is held in 2nd gear. If the solenoid is OFF, the A/T is held in 4th gear. (Engine brake is not applied in
1st and 2nd gear.)
Input Clutch Solenoid
If a malfunction (electrical or functional) occurs with the solenoid either ON or OFF, the A/T is held in 4th gear
to make driving possible.
Direct Clutch Solenoid
If a malfunction (electrical or functional) occurs with the solenoid either ON or OFF, the A/T is held in 4th gear
to make driving possible.
Front Brake Solenoid
If a malfunction (electrical or functional) occurs with the solenoid ON, in order to make driving possible, the A/
T is held in 5th gear. If the solenoid is OFF, the A/T 4th gear.
High and Low Reverse Clutch Solenoid
If a malfunction (electrical or functional) occurs with the solenoid either ON or OFF, the A/T is held in 4th gear
to make driving possible.
Turbine Revolution Sensor 1 or 2
The control is the same as if there were no turbine revolution sensors, 5th gear is prohibited.
Gear positionATF pressure switch output
Fail-safe
functionClutch pressure output pattern after fail-safe func-
tion
SW3
(I/C)SW6
(HLR/C)SW5
(D/C)SW1
(FR/B)SW2
(LC/B)I/C HLR/C D/C FR/B LC/B L/U
A/T interlock
coupling pat-
tern3rd – X X –lHeld in
2nd gearOFF OFF ON OFF OFF OFF
4th – X X –lHeld in
2nd gearOFF OFF ON OFF OFF OFF
5th X X – XlHeld in
2nd gearOFF OFF ON OFF OFF OFF
AT-36
TROUBLE DIAGNOSIS
How to Perform Trouble Diagnosis for Quick and Accurate Repair
ECS00FWX
INTRODUCTION
The TCM receives a signal from the vehicle speed sensor, accelera-
tor pedal position sensor or PNP switch and provides shift control or
lock-up control via A/T solenoid valves.
Input and output signals must always be correct and stable in the
operation of the A/T system. The A/T system must be in good oper-
ating condition and be free of valve seizure, solenoid valve malfunc-
tion, etc.
It is much more difficult to diagnose a error that occurs intermittently
rather than continuously. Most intermittent errors are caused by poor
electric connections or improper wiring. In this case, careful check-
ing of suspected circuits may help prevent the replacement of good
parts.
A visual check only may not find the cause of the errors. A road test
with CONSULT-II or a circuit tester connected should be performed.
Follow theAT-37, "
WORK FLOW".
Before undertaking actual checks, take a few minutes to talk with a
customer who approaches with a driveability complaint. The cus-
tomer can supply good information about such errors, especially
intermittent ones. Find out what symptoms are present and under
what conditions they occur. A “DIAGNOSTIC WORKSFEET” as
shown on the example (Refer toAT-38
) should be used.
Start your diagnosis by looking for “conventional” errors first. This will
help troubleshoot driveability errors on an electronically controlled
engine vehicle.
Also check related Service bulletins.
SAT631IB
SAT632I
SEF234G
TROUBLE DIAGNOSIS
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4oPerform all road tests and enter checks in required inspection items.AT- 4 6
4-1.Check Before Engine Is StartedAT- 4 6
oAT- 1 7 7 , "OD OFF Indicator Lamp Does Not Come On"
oPerform self-diagnosis. Enter checks for detected items.AT- 8 0,AT- 8 9
oAT-91, "DTC U1000 CAN COMMUNICATION LINE"
oAT-94, "DTC P0615 START SIGNAL CIRCUIT"
oAT-98, "DTC P0700 TCM"
oAT-99, "DTC P0705 PARK/NEUTRAL POSITION SWITCH"
oAT-103, "DTC P0720 VEHICLE SPEED SENSOR A/T (REVOLUTION SENSOR)"
oAT-108, "DTC P0725 ENGINE SPEED SIGNAL"
oAT-110, "DTC P0740 TORQUE CONVERTER CLUTCH SOLENOID VALVE"
oAT-112, "DTC P0744 A/T TCC S/V FUNCTION (LOCK-UP)"
oAT-114, "DTC P0745 LINE PRESSURE SOLENOID VALVE"
oAT-116, "DTC P1705 THROTTLE POSITION SENSOR"
oAT-118, "DTC P1710 A/T FLUID TEMPERATURE SENSOR CIRCUIT"
oAT-123, "DTC P1716 TURBINE REVOLUTION SENSOR"
oAT-125, "DTC P1721 VEHICLE SPEED SENSOR MTR"
oAT-127, "DTC P1730 A/T INTERLOCK"
oAT-130, "DTC P1731 A/T 1ST ENGINE BRAKING"
oAT-132, "DTC P1752 INPUT CLUTCH SOLENOID VALVE"
oAT-134, "DTC P1754 INPUT CLUTCH SOLENOID VALVE FUNCTION"
oAT-137, "DTC P1757 FRONT BRAKE SOLENOID VALVE"
oAT-139, "DTC P1759 FRONT BRAKE SOLENOID VALVE FUNCTION"
oAT-142, "DTC P1762 DIRECT CLUTCH SOLENOID VALVE"
oAT-144, "DTC P1764 DIRECT CLUTCH SOLENOID VALVE FUNCTION"
oAT-147, "DTC P1767 HIGH AND LOW REVERSE CLUTCH SOLENOID VALVE"
oAT-149, "DTC P1769 HIGH AND LOW REVERSE CLUTCH SOLENOID VALVE
FUNCTION"
oAT-152, "DTC P1772 LOW COAST BRAKE SOLENOID VALVE"
oAT-154, "DTC P1774 LOW COAST BRAKE SOLENOID VALVE FUNCTION"
oAT-156, "DTC P1841 ATF PRESSURE SWITCH 1"
oAT-158, "DTC P1843 ATF PRESSURE SWITCH 3"
oAT-160, "DTC P1845 ATF PRESSURE SWITCH 5"
oAT-162, "DTC P1846 ATF PRESSURE SWITCH 6"
4-2.Check at IdleAT- 4 7
oAT- 1 7 7 , "Engine Cannot Be Started in“P”or“N”Position"
oAT- 1 7 8 , "In“P”Position, Vehicle Moves When Pushed"
oAT- 1 7 9 , "In“N”Position, Vehicle Moves"
oAT- 1 8 0 , "Large Shock (“N”to“D”Position)"
oAT- 1 8 2 , "Vehicle Does Not Creep Backward in“R”Position"
oAT- 1 8 4 , "Vehicle Does Not Creep Forward in“D”Position"
4-3.Cruise TestAT- 4 8
Part 1
oAT- 1 8 6 , "
Vehicle Cannot Be Started from D1"
oAT- 1 8 8 , "A/T Does Not Shift: D1®D2"
oAT- 1 9 0 , "A/T Does Not Shift: D2®D3"
oAT- 1 9 2 , "A/T Does Not Shift: D3®D4"
oAT- 1 9 4 , "A/T Does Not Shift: D4®D5"
oAT- 1 9 6 , "A/T Does Not Perform Lock-up"
oAT- 1 9 7 , "A/T Does Not Hold Lock-up Condition"
oAT- 1 9 9 , "Lock-up Is Not Released"
oAT- 1 9 9 , "Engine Speed Does Not Return to Idle"
AT-40
TROUBLE DIAGNOSIS
44-3Part 2AT- 5 0
oAT-186, "Vehicle Cannot Be Started from D1"
oAT-188, "A/T Does Not Shift: D1®D2"
oAT-190, "A/T Does Not Shift: D2®D3"
oAT-192, "A/T Does Not Shift: D3®D4"
Part 3AT- 5 1
oAT-200, "A/T Does Not Shift: 5th Gear®4th Gear"
oAT-202, "A/T Does Not Shift: 4th Gear®3rd Gear"
oAT-203, "A/T Does Not Shift: 3rd Gear®2nd Gear"
oAT-204, "A/T Does Not Shift: 2nd Gear®1st Gear"
oAT-206, "Vehicle Does Not Decelerate by Engine Brake"
oPerform self-diagnosis. Enter checks for detected items.AT- 8 0,AT- 8 9
oAT- 9 1 , "DTC U1000 CAN COMMUNICATION LINE"
oAT- 9 4 , "DTC P0615 START SIGNAL CIRCUIT"
oAT- 9 8 , "DTC P0700 TCM"
oAT- 9 9 , "DTC P0705 PARK/NEUTRAL POSITION SWITCH"
oAT-103, "DTC P0720 VEHICLE SPEED SENSOR A/T (REVOLUTION SENSOR)"
oAT-108, "DTC P0725 ENGINE SPEED SIGNAL"
oAT- 11 0 , "DTC P0740 TORQUE CONVERTER CLUTCH SOLENOID VALVE"
oAT- 11 2 , "DTC P0744 A/T TCC S/V FUNCTION (LOCK-UP)"
oAT- 11 4 , "DTC P0745 LINE PRESSURE SOLENOID VALVE"
oAT- 11 6 , "DTC P1705 THROTTLE POSITION SENSOR"
oAT- 11 8 , "DTC P1710 A/T FLUID TEMPERATURE SENSOR CIRCUIT"
oAT-123, "DTC P1716 TURBINE REVOLUTION SENSOR"
oAT-125, "DTC P1721 VEHICLE SPEED SENSOR MTR"
oAT-127, "DTC P1730 A/T INTERLOCK"
oAT-130, "DTC P1731 A/T 1ST ENGINE BRAKING"
oAT-132, "DTC P1752 INPUT CLUTCH SOLENOID VALVE"
oAT-134, "DTC P1754 INPUT CLUTCH SOLENOID VALVE FUNCTION"
oAT-137, "DTC P1757 FRONT BRAKE SOLENOID VALVE"
oAT-139, "DTC P1759 FRONT BRAKE SOLENOID VALVE FUNCTION"
oAT-142, "DTC P1762 DIRECT CLUTCH SOLENOID VALVE"
oAT-144, "DTC P1764 DIRECT CLUTCH SOLENOID VALVE FUNCTION"
oAT-147, "DTC P1767 HIGH AND LOW REVERSE CLUTCH SOLENOID VALVE"
oAT-149, "DTC P1769 HIGH AND LOW REVERSE CLUTCH SOLENOID VALVE
FUNCTION"
oAT-152, "DTC P1772 LOW COAST BRAKE SOLENOID VALVE"
oAT-154, "DTC P1774 LOW COAST BRAKE SOLENOID VALVE FUNCTION"
oAT-156, "DTC P1841 ATF PRESSURE SWITCH 1"
oAT-158, "DTC P1843 ATF PRESSURE SWITCH 3"
oAT-160, "DTC P1845 ATF PRESSURE SWITCH 5"
oAT-162, "DTC P1846 ATF PRESSURE SWITCH 6"
5oInspect each system for items found to be NG in the self-diagnosis and repair or replace the malfunctioning parts.
6oPerform all road tests and enter the checks again for the required items.AT- 4 6
7oFor any remaining NG items, perform the “Diagnosis Procedure” and repair or replace the malfunctioning
parts. See the chart for diagnosis by symptoms. (This chart also contains other symptoms and inspection pro-
cedures.)AT- 5 3
8oErase the results of the self-diagnostics from TCM.AT- 8 2AT- 9 0
TROUBLE DIAGNOSIS
AT-45
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4. Securely engage the parking brake so that the tires do not turn.
5. Start the engine, then measure the line pressure at both idle and
the stall speed.
CAUTION:
lKeep the brake pedal pressed all the way down during
measurement.
lWhen measuring the line pressure at the stall speed.
Refer toAT-43, "
STALL TEST".
6. After the measurements are complete, install the oil pressure
detection plug and tighten to the specified torque. Refer toAT-
251, "Components".
CAUTION:
lDo not reuse O-ring.
lApply ATF to O-ring.
Line Pressure
Judgement of Line Pressure Test
SAT513G
SAT493G
Engine speedLine pressure [kPa (bar, kg/cm
2,psi)]
“R” position “D” position
At idle speed 425 - 465 (4.3 - 4.6, 4.3 - 4.7, 62 - 67) 379 - 428 (3.8 - 4.3, 3.9 - 4.4, 55 - 62)
At stall speed 1,605 - 1,950 (16.0 - 19.5, 16.4 - 19.9, 233 - 283) 1,310 - 1,500 (13.1 - 15.0, 13.4 - 15.3, 190 - 218)
Judgement Possible cause
Idle speedLow for all positions
(“P”, “R”, “N” and “D”)Possible causes include malfunctions in the pressure supply system and low oil pump output.
For example
lOil pump wear
lPressure regulator valve or plug sticking or spring fatigue
lOil straineroil pumppressure regulator valve passage oil leak
lEngine idle speed too low
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.
HighPossible causes include a sensor malfunction or malfunction in the line pressure adjustment
function.
For example
lAccelerator pedal position signal malfunction
lA/T fluid temperature sensor malfunction
lLine pressure solenoid malfunction (sticking in OFF state, filter clog, cut line)
lPressure regulator valve or plug sticking
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
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Symptom ChartECS00FX8
lThe diagnostic item numbers show the sequence for inspection. Inspect in order from item 1.
lOverhaul and inspect inside the A/T only if A/T fluid condition is NG. Refer toAT-43, "A/T Fluid Con-
dition Check".
No. Items Symptom Condition Diagnostic ItemReference
page
1
Shift
ShockLarge shock. (“N”®“D”
position)
Refer toAT-180,
"Large Shock (“N”to
“D”Position)".ON vehicle1. Engine idle speedEC-38
2. Engine speed signalAT-108
3. Accelerator pedal position sensorAT- 11 6
4. Control cable adjustmentAT- 2 11
5. A/T fluid temperature sensorAT- 11 8
6. ATF pressure switch 1 and front brake solenoid valveAT-156,
AT-137
7. CAN communication lineAT- 9 1
8. A/T fluid level and stateAT- 4 3
9. Line pressure testAT- 4 4
10. Control valve with TCMAT-218
OFF vehicle11. Forward brake (Parts behind drum support is impossible
to perform inspection by disassembly. Refer toAT- 1 4 , "Cross-
Sectional View (2WD Models)",AT- 1 5 , "Cross-Sectional View
(4WD Models)".)AT-263
2Shock is too large
when changing D1
®D2.ON vehicle1. Accelerator pedal position sensorAT- 11 6
2. Control cable adjustmentAT- 2 11
3. ATF pressure switch 5 and direct clutch solenoid valveAT-160,
AT-142
4. CAN communication lineAT- 9 1
5. Engine speed signalAT-108
6. Turbine revolution sensorAT-123
7. Vehicle speed sensor A/T and vehicle speed sensor MTRAT-103,
AT-125
8. A/T fluid level and stateAT- 4 3
9. Control valve with TCMAT-218
OFF vehicle 10. Direct clutchAT-298
3Shock is too large
when changing D2
®D3.ON vehicle1. Accelerator pedal position sensorAT- 11 6
2. Control cable adjustmentAT- 2 11
3. ATF pressure switch 6 and high and low reverse clutch
solenoid valveAT-162,
AT-147
4. CAN communication lineAT- 9 1
5. Engine speed signalAT-108
6. Turbine revolution sensorAT-123
7. Vehicle speed sensor A/T and vehicle speed sensor MTRAT-103,
AT-125
8. A/T fluid level and stateAT- 4 3
9. Control valve with TCMAT-218
OFF vehicle 10. High and low reverse clutchAT-296