
Introduction
The TCM receives a signal from the vehicle-speed sensor, throttle
(accelerator) position sensor or park/neutral position switch and
provides shift control or lock-up control via 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
operating condition and be free of valve seizure, solenoid valve
malfunction, 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
replacement 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 ªWork Flowº. Refer to AT-26.
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 problems, especially
intermittent ones. Find out what symptoms are present and under
what conditions they occur. A ªDiagnostic Worksheetº like the
example (AT-24) should be used.
Start your diagnosis by looking for ªconventionalº problems first.
This will help troubleshoot driveability problems on an electronically
controlled engine vehicle.
SAT631IA
SAT632I
SEF234G
TROUBLE DIAGNOSIS Ð Introduction
AT-22

DIAGNOSTIC WORKSHEET
1.lRead the Fail-safe and listen to customer complaints. AT-5
2.lA/T FLUID CHECK AT-27
lLeakage (Follow specified procedure)
lFluid condition
lFluid level
3.lPerform STALL TEST and LINE PRESSURE TEST. AT-27,
AT-30
lStall test Ð Mark possible damaged components/others.
lTorque converter one-way clutch
lReverse clutch
lForward clutch
lOverrun clutch
lForward one-way clutchlLow & reverse brake
lLow one-way clutch
lEngine
lLine pressure is low
lClutches and brakes except high
clutch and brake band are OK
lLine pressure test Ð Suspected parts:
4.lPerform all ROAD TEST and mark required procedures. AT-32
4-1. Check before engine is started. AT-33
lSELF-DIAGNOSTIC PROCEDURE Ð Mark detected items.
lVehicle speed sensor×A/T (Revolution sensor), AT-50.
lVehicle speed sensor×MTR, AT-54.
lThrottle (accelerator) position sensor, AT-60.
lShift solenoid valve A, AT-63.
lShift solenoid valve B, AT-66.
lOverrun clutch solenoid valve, AT-69.
lTorque converter clutch solenoid valve, AT-88.
lA/T fluid temperature sensor and TCM power source, AT-76.
lEngine speed signal, AT-80.
lLine pressure solenoid valve, AT-84.
lPark/neutral position, overdrive control, A/T check and throttle
(accelerator) position switches, AT-88.
lBattery
lOthers
4-2. Check at idle AT-35
l1. SPORT Indicator Lamp Does Not Come On, AT-92.
l2. SPORT or SNOW Indicator Lamp Does Not Come On, AT-95.
l3. O/D OFF Indicator Lamp Does Not Come On, AT-95.
l4. SPORT Indicator Lamp Does Not Come On, AT-96.
l5. Engine Cannot Be Started In ªPº And ªNº Position, AT-97.
l6. In ªPº Position, Vehicle Moves Forward Or Backward When Pushed, AT-97.
l7. In ªNº Position, Vehicle Moves, AT-98.
l8. Large Shock. ªNº,ªRº Position, AT-99.
l9. Vehicle Does Not Creep Backward In ªRº Position, AT-100.
l10. Vehicle Does Not Creep Forward In ªDº, ª2º Or ª1º Position, AT-101.
4-3. Cruise testAT-36,
AT-39
Part-1
l11. Vehicle Cannot Be Started From D
1, AT-102.
l12. A/T Does Not Shift: D
1,D2Or Does Not Kickdown: D4,D2, AT-103.
l13. A/T Does Not Shift: D
2,D3, AT-104.
l14. A/T Does Not Shift: D
3,D4, AT-105.
l15. A/T Does Not Perform Lock-up, AT-106.
l16. A/T Does Not Hold Lock-up Condition, AT-107.
l17. Lock-up Is Not Released, AT-107.
l18. Engine Speed Does Not Return To Idle (Light Braking D
4,D3), AT-108.
TROUBLE DIAGNOSIS Ð Introduction
Diagnostic Worksheet (Cont'd)
AT-24

4. Part-2
l19. Vehicle Does Not Start From D
1, AT-109.
l12. A/T Does Not Shift: D
1,D2Or Does Not Kickdown: D4,D2, AT-103.
l13. A/T Does Not Shift: D
2,D3, AT-104.
l14. A/T Does Not Shift: D
3,D4, AT-105.AT-41
Part-3
l20. A/T Does Not Shift: D
2,D1When Depressing Accelerator Pedal, AT-5.
l21. A/T Does Not Shift: D
4,D3When Overdrive Control Switch ªONº,
ªOFFº, AT-111.
l18. Engine Speed Does Not Return To Idle (Engine Brake In D
3), AT-108.
l22. A/T Does Not Shift: D
3,22, When Selector Lever ªDº,ª2º Position,
AT- 111 .
l18. Engine Speed Does Not Return To Idle (Engine Brake In 2
2), AT-108.
l23. A/T Does Not Shift: 2
2,11, When Selector Lever ª2º,ª1º Position,
AT-5.
l24. Vehicle Does Not Decelerate By Engine Brake, AT-112.
lSELF-DIAGNOSTIC PROCEDURE Ð Mark detected items.AT-42
lVehicle speed sensor×A/T (Revolution sensor), AT-50.
lVehicle speed sensor×MTR, AT-54.
lThrottle (accelerator) position sensor, AT-60.
lShift solenoid valve A, AT-63.
lShift solenoid valve B, AT-66.
lOverrun clutch solenoid valve, AT-69.
lTorque converter clutch solenoid valve, AT-69.
lA/T fluid temperature sensor and TCM power source, AT-76.
lEngine speed signal, AT-80.
lLine pressure solenoid valve, AT-84.
lPark/neutral position, overdrive control, A/T check and throttle
(accelerator) position switches, AT-88.
lBattery
lOthers
5.lFor self-diagnosis NG items, inspect each component. Repair or replace the
damaged parts.AT-14
6.lPerform all ROAD TEST and re-mark required procedures. AT-32
7.lPerform the Diagnostic Procedures for all remaining items marked NG. Repair or
replace the damaged parts.
Refer to the Symptom Chart when you perform the procedures. (The chart also
shows some other possible symptoms and the component inspection orders.)AT-46
AT-43
8.lErase self-diagnosis code from TCM memories. AT-19
TROUBLE DIAGNOSIS Ð Introduction
Diagnostic Worksheet (Cont'd)
AT-25

A/T Fluid Check
FLUID LEAKAGE CHECK
1. Clean area suspected of leaking. Ð for example, mating sur-
face of converter housing and transmission case.
2. Start engine, apply foot brake, place selector lever in ªDº posi-
tion and wait a few minutes.
3. Stop engine.
4. Check for fresh leakage.
FLUID CONDITION CHECK
Fluid color Suspected problem
Dark or black with burned odor Wear of frictional material
Milky pinkWater contamination Ð Road water enter-
ing through filler tube or breather
Varnished fluid, light to dark
brown and tackyOxidation Ð Over or under filling, Ð Over-
heating
FLUID LEVEL CHECK
Refer to MA section (ªChecking A/T Fluidº, ªCHASSIS AND BODY
MAINTENANCEº).
Stall Test
STALL TEST PROCEDURE
1. Check A/T and engine fluid levels. If necessary, add.
2. Drive vehicle for approx. 10 minutes or until engine oil and ATF
reach operating temperature.
ATF operating temperature:
50 - 80ÉC (122 - 176ÉF)
3. Set parking brake and block wheels.
4. Install a tachometer where it can be seen by driver during test.
IIt is good practice to put a mark on point of specified
engine rpm on indicator.
5. Start engine, apply foot brake, and place selector lever in ªDº
position.
6. Accelerate to wide open throttle gradually while applying foot
brake.
7. Quickly note the engine stall revolution and immediately
release throttle.
IDuring test, never hold throttle wide open for more than 5
seconds.
Stall revolution:
2,450 - 2,700 rpm
SAT801A
SAT638A
SAT647B
SAT513G
SAT514G
TROUBLE DIAGNOSIS Ð Basic Inspection
AT-27

8. Move selector lever to ªNº position.
9. Cool off ATF.
IRun engine at idle for at least one minute.
10. Repeat steps 5 through 9 with selector lever in ª2º, ª1º and ªRº
positions.
JUDGEMENT OF STALL TEST
The test result and possible damaged components relating to each result are shown in the illustration.
In order to pinpoint the possible damaged components, follow the WORK FLOW as shown in AT-26.
Note
Stall revolution is too high in ªDº or ª2º position:
ISlippage occurs in 1st gear but not in 2nd and 3rd gears. ..... Low one-way clutch slippage
ISlippage occurs at the following gears:
1st through 3rd gears in ªDº position and engine brake functions.
1st and 2nd gears in ª2º position and engine brake functions with accelerator pedal released (fully closed
throttle). ..... Forward clutch or forward one-way clutch slippage
Stall revolution is too high in ªRº position:
IEngine brake does not function in ª1º position. ..... Low & reverse brake slippage
IEngine brake functions in ª1º position. ..... Reverse clutch slippage
Stall revolution within specifications:
IVehicle does not achieve speed of more than 80 km/h (50 MPH). ..... One-way clutch seizure in torque
converter housing
CAUTION:
Be careful since automatic fluid temperature increases abnormally.
ISlippage occurs in 3rd and 4th gears in ªDº position. ..... High clutch slippage
ISlippage occurs in 2nd and 4th gears in ªDº position. ..... Brake band slippage
Stall revolution less than specifications:
IPoor acceleration during starts. ..... One-way clutch seizure in torque converter
SAT771B
TROUBLE DIAGNOSIS Ð Basic Inspection
Stall Test (Cont'd)
AT-28

4. Set parking brake and block wheels.
IContinue to depress brake pedal fully while line pressure
test is being performed at stall speed.
5. Start engine and measure line pressure at idle and stall speed.
IWhen measuring line pressure at stall speed, follow the
stall test procedure.
Line pressure:
Refer to SDS, AT-196.
JUDGEMENT OF LINE PRESSURE TEST
Judgement Suspected parts
At idleLine pressure is low in all
positions.IOil pump wear
IControl piston damage
IPressure regulator valve or plug sticking
ISpring for pressure regulator valve damaged
IA/T fluid pressure leakage between oil strainer and pressure regulator valve
IClogged strainer
Line pressure is low in par-
ticular position.IFluid pressure leakage between manual valve and particular clutch
IFor example, line pressure is:
Ð Low in ªRº and ª1º positions,
Ð Normal in ªDº and ª2º positions.
Then, fluid leakage exists at or around low and reverse brake circuit.
Refer to ªCLUTCH AND BAND CHARTº, AT-11.
Line pressure is high.IMal-adjustment of throttle position sensor
IA/T fluid temperature sensor damaged
ILine pressure solenoid valve sticking
IShort circuit of line pressure solenoid valve circuit
IPressure modifier valve sticking
IPressure regulator valve or plug sticking
IOpen in dropping resistor circuit
At stall speedLine pressure is low.IMal-adjustment of throttle position sensor
ILine pressure solenoid valve sticking
IShort circuit of line pressure solenoid valve circuit
IPressure regulator valve or plug sticking
IPressure modifier valve sticking
IPilot valve sticking
SAT513G
SAT493G
TROUBLE DIAGNOSIS Ð Basic Inspection
Line Pressure Test (Cont'd)
AT-31

Road Test
DESCRIPTION
IThe purpose of the test is to determine overall performance of
A/T and analyze causes of problems.
IThe road test consists of the following three parts:
1. Check before engine is started
2. Check at idle
3. Cruise test
IBefore road test, familiarize yourself with all test procedures
and items to check.
IConduct tests on all items until specified symptom is found.
Troubleshoot items which check out No Good after road test.
Refer to ªON BOARD DIAGNOSTIC SYSTEM DESCRIPTIONº
and ªDIAGNOSTIC PROCEDURES FOR SYMPTOMSº, AT-14
- AT-20 and AT-92 - AT-112.
SAT786A
SAT496G
TROUBLE DIAGNOSIS Ð Basic Inspection
AT-32

1. CHECK BEFORE ENGINE IS STARTED
1. Park vehicle on flat surface.
2. Turn ignition switch to ªOFFº position.
1. Set A/T mode switch to ªAUTOº posi-
tion.
2. Move selector lever to ªPº position.
3. Turn ignition switch to ªONº position.
(Do not start engine.)
4. Does SPORT indicator lamp come on
for about 2 seconds?
Ye s
ENo
Go to 1. SPORT Indicator
Lamp Does Not Come On,
AT-92.
Does SPORT indicator lamp flicker for
about 8 seconds?
No
EYe s
Perform self-diagnosis.
Refer to SELF-DIAGNO-
SIS PROCEDURE, AT-14.
1. Set A/T mode switch to ªSPORTº posi-
tion.
2. Does SPORT indicator lamp come on?
Ye s
ENo
Go to 2. SPORT or SNOW
(*) Indicator Lamp Does
Not Come On, AT-95.
Set overdrive control switch to ªOFFº posi-
tion.
Does O/D OFF indicator lamp come on?
Ye s
ENo
Go to 3. O/D OFF Indica-
tor Lamp Does Not Come
On, AT-95.
qA
(Go to next page.)
NAT309
SAT853E
NAT309
SAT857E
NAT232
H
H
H
H
H
H
TROUBLE DIAGNOSIS Ð Basic Inspection
Road Test (Cont'd)
AT-33