AT-258
[EXC.F/EURO-OBD]
TROUBLE DIAGNOSIS — INTRODUCTION
TROUBLE DIAGNOSIS — INTRODUCTION
PFP:00000
IntroductionECS004TF
The TCM receives a signal from the vehicle speed sensor, throttle
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 problem that occurs intermit-
tently rather than continuously. Most intermittent problems are
caused by poor electric connections or improper wiring. In this case,
careful checking of suspected circuits may help prevent the replace-
ment of good parts.
A visual check only, may not find the cause of the problems. A road
test with CONSULT-II or a circuit tester connected should be per-
formed. Follow the “Work Flow”. Refer to AT- 6 0
.
Before undertaking actual checks, take a few minutes to talk with a
customer who approaches with a drive ability complaint. The cus-
tomer can supply good information about such problems, especially
intermittent ones. Find out what symptoms are present and under
what conditions they occur. A “Diagnostic Worksheet” like the exam-
ple (AT- 5 7
) should be used.
Start your diagnosis by looking for “conventional” problems first. This
will help troubleshoot drive ability problems on an electronically con-
trolled engine vehicle.
Also check related Service bulletins for information.
SAT631IA
SAT632I
SEF234G
AT-260
[EXC.F/EURO-OBD]
TROUBLE DIAGNOSIS — INTRODUCTION
Diagnostic Worksheet
1.❏ Read the Fail-safe and listen to customer complaints.AT- 8 , "Wiring
Diagrams
and Trouble
Diagnosis",
AT-259,
"DIAGNOS-
TIC WORK-
SHEET"
2.❏ CHECK A/T FLUIDAT-264, "A/T
Fluid Check"❏ Leakage (Follow specified procedure)
❏ Fluid condition
❏ Fluid level
3.❏ Perform STALL TEST and LINE PRESSURE TEST.AT- 2 6 5 , "
Stall
Te s t",
AT-268, "
Line
Pressure
Te s t"
❏ Stall test — Mark possible damaged components/others.
❏ Torque converter one-way clutch
❏ Reverse clutch
❏ Forward clutch
❏ Overrun clutch
❏ Forward one-way clutch❏ Low & reverse brake
❏ Low one-way clutch
❏ Engine
❏ Line pressure is low
❏ Clutches and brakes except high clutch and
brake band are OK
❏ Line Pressure test — Suspected parts:
4.❏ Perform all ROAD TEST and mark required procedures.AT-269,
"Road Test"
4-1. Check before engine is started.AT-271, "1.
CHECK
BEFORE
ENGINE IS
STARTED"
❏ O/D OFF Indicator Lamp Does Not Come On, AT-312 .
❏ SELF-DIAGNOSTIC CONFIRMATION PROCEDURE — Mark detected items.
❏ Vehicle speed sensor·A/T (Revolution sensor), AT-353
.
❏ Vehicle speed sensor·MTR, AT- 3 5 8
.
❏ Accelerator pedal position (APP) sensor, AT-362
.
❏ Shift solenoid valve A, AT-367
.
❏ Shift solenoid valve B, AT-372
.
❏ Overrun clutch solenoid valve, AT-377
.
❏ Torque converter clutch solenoid valve, AT- 3 8 1
.
❏ A/T fluid temperature sensor and TCM power source, AT-386
.
❏ Engine speed signal, AT-392
.
❏ Line pressure solenoid valve, AT-396
.
❏ CAN communication line, AT-403
.
❏ Control unit (RAM), control unit (ROM), AT- 2 0 3 , "
DTC CONTROL UNIT (RAM), CONTROL UNIT
(ROM)" .
❏ Control unit (EEP ROM), AT- 2 0 5 , "
DTC CONTROL UNIT(EEPROM)" .
❏ PNP & overdrive control switches, and throttle position sensor, AT- 3 4 4
.
❏ Battery
❏ Others
4-2. Check at idleAT-272, "
2.
CHECK AT
IDLE"❏ Engine Cannot Be Started In “P” And “N” Position, AT-314 .
❏ In “P” Position, Vehicle Moves Forward Or Backward When Pushed, AT- 3 1 5
.
❏ In “N” Position, Vehicle Moves, AT- 3 1 5
.
❏ Large Shock. “N” → “R” Position, AT-317
.
❏ Vehicle Does Not Creep Backward In “R” Position, AT- 3 1 7
.
❏ Vehicle Does Not Creep Forward In “D”, “2” Or “1” Position, AT- 3 2 1
.
TROUBLE DIAGNOSIS — INTRODUCTION
AT-261
[EXC.F/EURO-OBD]
D
E
F
G
H
I
J
K
L
MA
B
AT
4. 4-3. Cruise testAT- 2 7 5 , "3.
CRUISE
TEST",
AT- 2 7 9 ,
"Cruise Test
— Part 1"
Part-1
❏ Vehicle Cannot Be Started From D
1 , AT- 3 2 3 .
❏ A/T Does Not Shift: D
1→ D2 Or Does Not Kickdown: D4→ D2 , AT- 3 2 6 .
❏ A/T Does Not Shift: D
2→ D3 , AT-328 .
❏ A/T Does Not Shift: D
3→ D4 , AT-330 .
❏ A/T Does Not Perform Lock-up,AT- 3 3 2
.
❏ A/T Does Not Hold Lock-up Condition, AT-333
.
❏ Lock-up Is Not Released, AT-335
.
❏ Engine Speed Does Not Return To Idle (Light Braking D
4→ D3 ), AT- 3 3 6 .
Part-2AT- 2 8 2 ,
"Cruise Test
— Part 2"❏ Vehicle Does Not Start From D1 , AT-338 .
❏ A/T Does Not Shift: D
1→ D2 Or Does Not Kickdown: D4→ D2 , AT- 3 2 6 .
❏ A/T Does Not Shift: D
2→ D3 , AT-328 .
❏ A/T Does Not Shift: D
3→ D4 , AT-330 .
Part-3AT- 2 8 4 ,
"Cruise Test
— Part 3"❏ A/T Does Not Shift: D4→ D3 When Overdrive Control Switch “ON” → “OFF”, AT- 3 3 9 .
❏ Engine Speed Does Not Return To Idle (Engine Brake In D
3 ), AT-336 .
❏ A/T Does Not Shift: D
3→ 22 , When Selector Lever “D” → “2” Position, AT- 3 4 0 .
❏ Engine Speed Does Not Return To Idle (Engine Brake In 2
2 ),AT- 3 3 6 .
❏ A/T Does Not Shift: 2
2→ 11 , When Selector Lever “2” → “1” Position, AT- 3 4 1 .
❏ Vehicle Does Not Decelerate By Engine Brake, AT-343
.
❏ TCM Self-diagnosis Does Not Activate (PNP & Overdrive Control Switches, and throttle position sensor
Circuit Checks), AT- 3 4 4
.
❏ SELF-DIAGNOSTIC PROCEDURE — Mark detected items.
❏ Vehicle speed sensor·A/T (Revolution sensor), AT- 3 5 3
.
❏ Vehicle speed sensor·MTR, AT-358
.
❏ Accelerator pedal position (APP) sensor, AT-362
.
❏ Shift solenoid valve A, AT- 3 6 7
.
❏ Shift solenoid valve B, AT- 3 7 2
.
❏ Overrun clutch solenoid valve, AT- 3 7 7
.
❏ Torque converter clutch solenoid valve, AT-381
.
❏ Batt/fluid temp sen (A/T fluid temperature sensor and TCM power source), AT- 3 8 6
.
❏ Engine speed signal, AT- 3 9 2
.
❏ Line pressure solenoid valve, AT-396
.
❏ CAN communication line, AT- 4 0 3
.
❏ Control unit (RAM), control unit (ROM), AT-203, "
DTC CONTROL UNIT (RAM), CONTROL UNIT
(ROM)" .
❏ Control unit (EEP ROM), AT-205, "
DTC CONTROL UNIT(EEPROM)" .
❏ PNP & overdrive control switches, and throttle position sensor, AT- 3 4 4
.
❏ Battery
❏ Others
5.❏ For self-diagnosis NG items, inspect each component. Repair or replace the damaged parts.AT- 2 5 3 ,
"SELF-DIAG-
NOSTIC
PROCE-
DURE
(WITHOUT
CONSULT-
II)"
6.❏ Perform all ROAD TEST and re-mark required procedures.AT- 2 6 9 ,
"Road Test"
TROUBLE DIAGNOSIS — GENERAL DESCRIPTION
AT-287
[EXC.F/EURO-OBD]
D
E
F
G
H
I
J
K
L
MA
B
AT
TROUBLE DIAGNOSIS — GENERAL DESCRIPTIONPFP:00000
Symptom ChartECS004VV
Numbers are arranged in order of inspection.
Perform inspections starting with number one and work up.
Symptom Condition Diagnostic Item Reference Page
Engine cannot start in “P” and “N”
positions.
AT-314, "
Engine Cannot Be Started In
“P” and “N” Position"
ON vehicle1. Ignition switch and starterPG-2, "
POWER SUPPLY
ROUTING",
SC-20, "
STARTING SYS-
TEM"
2. Control cable adjustmentAT- 4 1 6 , "Control Cable
Adjustment"
3. PNP switchAT- 3 4 4 , "TCM Self-diag-
nosis Does Not Activate"
Engine starts in position other than
“N” and “P” positions.
AT-314, "
Engine Cannot Be Started In
“P” and “N” Position"
ON vehicle1. Control cable adjustmentAT- 4 1 6 , "
Control Cable
Adjustment"
2. PNP switchAT- 3 4 4 , "TCM Self-diag-
nosis Does Not Activate"
Transaxle noise in “P” and “N” posi-
tions.ON vehicle1. Fluid levelAT- 2 6 4 , "
FLUID LEVEL
CHECK"
2. Line pressure testAT- 2 6 8 , "Line Pressure
Te s t"
3. Accelerator pedal position (APP) sensorAT- 3 6 2 , "
ACCELE
RATOR PEDAL POSI-
TION (APP) SENSOR"
4. Vehicle speed sensor·A/T (Revolution
sensor) and vehicle speed sensor·MTRAT- 3 5 3 , "
VEHICLE
SPEED SENSOR·A/T
(REVOLUTION SEN-
SOR)",
AT- 3 5 8 , "
DTC VEHICLE
SPEED SENSOR MTR"
OFF vehicle5. Oil pumpAT- 4 4 4 , "
Oil Pump"
6. Torque converterAT- 4 2 5 , "
Locations of
Adjusting Shims, Needle
Bearings, Thrust Washers
and Snap Rings"
Vehicle moves when changing into “P”
position, or parking gear does not dis-
engage when shifted out of “P” posi-
tion.
AT-315, "
In “P” Position, Vehicle
Moves Forward Or Backward When
Pushed"
ON vehicle 1. Control cable adjustmentAT- 4 1 6 , "Control Cable
Adjustment"
OFF vehicle 2. Parking componentsAT- 4 2 1 , "
Components",
AT- 4 4 1 , "
REPAIR FOR
COMPONENT PARTS"
Vehicle runs in “N” position.
AT-315, "
In “N” Position, Vehicle
Moves"
ON vehicle 1. Control cable adjustmentAT- 4 1 6 , "Control Cable
Adjustment"
OFF vehicle2. Forward clutchAT- 4 7 1 , "
Forward and
Overrun Clutches"
3. Reverse clutchAT- 4 6 3 , "Reverse Clutch"
4. Overrun clutchAT- 4 7 1 , "Forward and
Overrun Clutches"
TROUBLE DIAGNOSIS — GENERAL DESCRIPTION
AT-289
[EXC.F/EURO-OBD]
D
E
F
G
H
I
J
K
L
MA
B
AT
Sharp shock in shifting from “N” to “D”
position.ON vehicle1. Engine idling rpmEC-1391, "
I d l e S p e e d a n d
Ignition Timing"
2. Accelerator pedal position (APP) sensorAT- 3 6 2 , "
ACCELE
RATOR PEDAL POSI-
TION (APP) SENSOR"
3. Line pressure testAT- 2 6 8 , "Line Pressure
Te s t"
4. A/T fluid temp sen circ and TCM pow
sourAT- 3 8 6 , "
BATT/FLUID
TEMP SEN (A/T FLUID
TEMP SENSOR CIR-
CUIT AND TCM POWER
SOURCE)"
5. Engine speed signalAT- 3 9 2 , "ENGINE SPEED
SIGNAL"
6. Line pressure solenoid valveAT- 3 9 6 , "
LINE PRES-
SURE SOLENOID
VA LV E"
7. Control valve assemblyAT- 4 1 4 , "
Control Valve
Assembly and Accumula-
tors"
8. Accumulator N-DAT- 4 1 4 , "
Control Valve
Assembly and Accumula-
tors"
OFF vehicle 9. Forward clutchAT- 4 7 1 , "Forward and
Overrun Clutches"
Vehicle will not run in “D” and “2” posi-
tions (but runs in “1” and “R” posi-
tions).ON vehicle 1. Control cable adjustmentAT- 4 1 6 , "
Control Cable
Adjustment"
OFF vehicle 2. Low one-way clutchAT- 4 2 1 , "
OVERHAUL",
AT- 4 2 5 , "
Locations of
Adjusting Shims, Needle
Bearings, Thrust Washers
and Snap Rings"
Vehicle will not run in “D”, “1”, “2” posi-
tions (but runs in “R” position). Clutch
slips. Very poor acceleration.
AT-321, "
Vehicle Does Not Creep For-
ward In “D”,“2” Or “1” Position"
ON vehicle1. Fluid levelAT- 2 6 4 , "
FLUID LEVEL
CHECK"
2. Stall testAT- 2 6 5 , "Stall Tes t"
3. Line pressure testAT- 2 6 8 , "Line Pressure
Te s t"
4. Line pressure solenoid valveAT- 3 9 6 , "
LINE PRES-
SURE SOLENOID
VA LV E"
5. Control valve assemblyAT- 4 1 4 , "
Control Valve
Assembly and Accumula-
tors"
6. Accumulator N-DAT- 4 1 4 , "
Control Valve
Assembly and Accumula-
tors"
Symptom Condition Diagnostic Item Reference Page
AT-290
[EXC.F/EURO-OBD]
TROUBLE DIAGNOSIS — GENERAL DESCRIPTION
Vehicle will not run in “D”, “1”, “2” posi-
tions (but runs in “R” position). Clutch
slips. Very poor acceleration.
AT- 3 2 1 , "
Vehicle Does Not Creep For-
ward In “D”,“2” Or “1” Position"
OFF vehicle7. Reverse clutch AT-463, "
Reverse Clutch"
8. High clutchAT-466, "High Clutch"
9. Forward clutchAT-471, "Forward and
Overrun Clutches"
10. Forward one-way clutchAT-421, "OVERHAUL"
11. Low one-way clutchAT-421, "
OVERHAUL",
AT-425, "
Locations of
Adjusting Shims, Needle
Bearings, Thrust Washers
and Snap Rings"
Clutches or brakes slip somewhat in
starting.ON vehicle1. Fluid levelAT-264, "
FLUID LEVEL
CHECK"
2. Control cable adjustmentAT-416, "Control Cable
Adjustment"
3. Accelerator pedal position (APP) sensorAT-362, "
ACCELE
RATOR PEDAL POSI-
TION (APP) SENSOR"
4. Line pressure testAT-268, "Line Pressure
Te s t"
5. Line pressure solenoid valveAT-396, "
LINE PRES-
SURE SOLENOID
VA LV E"
6. Control valve assemblyAT-414, "
Control Valve
Assembly and Accumula-
tors"
7. Accumulator N-DAT-414, "
Control Valve
Assembly and Accumula-
tors"
8. Shift solenoid valve AAT-367, "SHIFT SOLE-
NOID VALVE A"
9. Shift solenoid valve BAT-372, "SHIFT SOLE-
NOID VALVE B"
10. Overrun clutch solenoid valveAT-377, "
OVERRUN
CLUTCH SOLENOID
VA LV E"
11. Torque converter clutch solenoid valveAT-381, "
TORQUE CON-
VERTER CLUTCH
SOLENOID VALVE"
OFF vehicle12. Forward clutchAT-471, "
Forward and
Overrun Clutches"
13. Reverse clutchAT-463, "Reverse Clutch"
14. Low & reverse brakeAT-476, "Low & Reverse
Brake"
15. Oil pumpAT-444, "Oil Pump"
16. Torque converterAT-425, "
Locations of
Adjusting Shims, Needle
Bearings, Thrust Washers
and Snap Rings"
Excessive creep. ON vehicle 1. Engine idling rpmEC-1391, "Idle Speed and
Ignition Timing"
Symptom Condition Diagnostic Item Reference Page
TROUBLE DIAGNOSIS — GENERAL DESCRIPTION
AT-291
[EXC.F/EURO-OBD]
D
E
F
G
H
I
J
K
L
MA
B
ATNo creep at all.
AT-318, "
Vehicle Does Not Creep
Backward In “R” Position" and AT-
321, "Vehicle Does Not Creep For-
ward In “D”,“2” Or “1” Position"
ON vehicle1. Fluid levelAT- 2 6 4 , "
FLUID LEVEL
CHECK"
2. Line pressure testAT- 3 9 6 , "
LINE PRES-
SURE SOLENOID
VA LV E"
3. Control valve assemblyAT- 4 1 4 , "
Control Valve
Assembly and Accumula-
tors"
OFF vehicle4. Forward clutchAT- 4 7 1 , "
Forward and
Overrun Clutches"
5. Oil pumpAT- 4 4 4 , "Oil Pump"
6. Torque converterAT- 4 2 5 , "
Locations of
Adjusting Shims, Needle
Bearings, Thrust Washers
and Snap Rings"
Failure to change gear from “D1 ” to
“D
2 ”.ON vehicle1. Control cable adjustmentAT- 4 1 6 , "
Control Cable
Adjustment"
2. Shift solenoid valve AAT- 3 6 7 , "SHIFT SOLE-
NOID VALVE A"
3. Control valve assemblyAT- 4 1 4 , "
Control Valve
Assembly and Accumula-
tors"
4. Vehicle speed sensor·A/T (Revolution
sensor) and vehicle speed sensor·MTRAT- 3 5 3 , "
VEHICLE
SPEED SENSOR·A/T
(REVOLUTION SEN-
SOR)",AT-358, "DTC
VEHICLE SPEED SEN-
SOR MTR"
5. Accelerator pedal position (APP) sensorAT- 3 6 2 , "
ACCELE
RATOR PEDAL POSI-
TION (APP) SENSOR"
OFF vehicle 6. Brake bandAT- 4 8 8 , "Band Servo Pis-
ton Assembly"
Failure to change gear from “D2 ” to
“D
3 ”.ON vehicle1. Control cable adjustmentAT- 4 1 6 , "
Control Cable
Adjustment"
2. Shift solenoid valve BAT- 3 7 2 , "SHIFT SOLE-
NOID VALVE B"
3. Control valve assemblyAT- 4 1 4 , "
Control Valve
Assembly and Accumula-
tors"
4. Vehicle speed sensor·A/T (Revolution
sensor) and vehicle speed sensor·MTRAT- 3 5 3 , "
VEHICLE
SPEED SENSOR·A/T
(REVOLUTION SEN-
SOR)",AT-358, "DTC
VEHICLE SPEED SEN-
SOR MTR"
5. Accelerator pedal position (APP) sensorAT- 3 6 2 , "
ACCELE
RATOR PEDAL POSI-
TION (APP) SENSOR"
OFF vehicle6. High clutchAT- 4 6 6 , "
High Clutch"
7. Brake bandAT- 4 8 8 , "Band Servo Pis-
ton Assembly"
Symptom Condition Diagnostic Item Reference Page
AT-292
[EXC.F/EURO-OBD]
TROUBLE DIAGNOSIS — GENERAL DESCRIPTION
Failure to change gear from “D3 ” to
“D
4 ”.ON vehicle1. PNP switchAT-344, "
TCM Self-diag-
nosis Does Not Activate"
2. Overrun clutch solenoid valveAT-377, "
OVERRUN
CLUTCH SOLENOID
VA LV E"
3. Shift solenoid valve AAT-367, "SHIFT SOLE-
NOID VALVE A"
4. Vehicle speed sensor·A/T (Revolution
sensor) and vehicle speed sensor·MTRAT-353, "
VEHICLE
SPEED SENSOR·A/T
(REVOLUTION SEN-
SOR)",AT-358, "DTC
VEHICLE SPEED SEN-
SOR MTR"
5. A/T fluid temp sen circ and TCM pow
sourAT-386, "
BATT/FLUID
TEMP SEN (A/T FLUID
TEMP SENSOR CIR-
CUIT AND TCM POWER
SOURCE)"
OFF vehicle 6. Brake bandAT-488, "Band Servo Pis-
ton Assembly"
Too high a gear change point from “D1
” to “D2 ”, from “D2 ” to “D3 ”, from “D3
” to “D4 ”.
AT- 3 2 6 , "
A/T Does Not Shift: D1→ D2
Or Does Not Kick down: D4→ D2"
andAT-330, "A/T Does Not Shift: D3
→ D4"
ON vehicle1. Accelerator pedal position (APP) sensorAT-362, "
ACCELE
RATOR PEDAL POSI-
TION (APP) SENSOR"
2. Vehicle speed sensor·A/T (Revolution
sensor) and vehicle speed sensor·MTRAT-353, "
VEHICLE
SPEED SENSOR·A/T
(REVOLUTION SEN-
SOR)",AT-358, "DTC
VEHICLE SPEED SEN-
SOR MTR"
3. Shift solenoid valve AAT-367, "SHIFT SOLE-
NOID VALVE A"
4. Shift solenoid valve BAT-372, "SHIFT SOLE-
NOID VALVE B"
Gear change directly from “D1 ” to “D3
” occurs.ON vehicle1. Fluid levelAT-264, "
FLUID LEVEL
CHECK"
2. Accumulator servo releaseAT-414, "
Control Valve
Assembly and Accumula-
tors"
OFF vehicle 3. Brake bandAT-488, "Band Servo Pis-
ton Assembly"
Engine stops when shifting lever into
“R”, “D”, “2” and “1”.ON vehicle1. Engine idling rpmEC-1391, "
Idle Speed and
Ignition Timing"
2. Fluid levelAT-264, "FLUID LEVEL
CHECK"
3. Torque converter clutch solenoid valveAT-381, "
TORQUE CON-
VERTER CLUTCH
SOLENOID VALVE"
4. Control valve assemblyAT-414, "
Control Valve
Assembly and Accumula-
tors"
OFF vehicle 5. Torque converterAT-425, "
Locations of
Adjusting Shims, Needle
Bearings, Thrust Washers
and Snap Rings"
Symptom Condition Diagnostic Item Reference Page