Part - 1

TROUBLE DIAGNOSIS

DTC Inspection Priority Chart

If some DTCs are displayed at the same time, perform inspections one by one based on the following priority chart.
NOTE:
If DTC "CAN COMM CIRCUIT" is displayed with other DTCs, first perform the trouble diagnosis for
DTC "CAN COMM CIRCUIT".







Fail-Safe

The TCM has an electronic Fail-safe mode. This allows the vehicle to be driven even if a major electrical input/
output device circuit is damaged.
Under Fail-Safe, the vehicle always runs in 3GR, even with a shift lever position of "1", "2" or "D". The customer may complain of sluggish or poor acceleration.
Always follow the " ".
The SELF-DIAGNOSIS results will be as follows:
- The first SELF-DIAGNOSIS will indicate damage to the vehicle speed signal or the output speed sensor.
- During the next SELF-DIAGNOSIS, performed after checking the sensor, no damages will be indicated.

FAIL-SAFE FUNCTION

The following fail-safe functions allow vehicles to be driven even when sensor, switch or solenoid malfunction occurs.
Output Speed Sensor
Vehicle speed signal is input from combination meter.
Accelerator Pedal Position Signal and Throttle Position Signal
TCM controls the throttle opening angle to a predetermined fixed position to enable driving if a malfunctioning signal is input to TCM.
Transmission Range Switch
When the multiple transmission range switch signals are input to TCM, the priority of selector lever position becomes "D", "N", "R", "2" and "1" in order by internal TCM determination.
The use of 4GR is inhibited until normal operation resumes. Because the hydraulic circuit of the control valve is switched by manual valve according to the selector lever position, however, actual operating condition of vehicle becomes as follows.





Shift Solenoid Valve A and B
If non-standard solenoid signal is sent to TCM, use of certain gears is limited. Refer to chart shown below.





Line Pressure Solenoid Valve
If non-standard solenoid signal is sent to TCM, line pressure solenoid valve is turned OFF to achieve maximum oil pressure.
Torque Converter Clutch Solenoid Valve
If non-standard solenoid signal is sent to TCM, torque converter clutch solenoid valve is turned OFF to release lock-up.
Overrun Clutch Solenoid Valve
If non-standard solenoid signal is sent to TCM, overrun clutch solenoid valve is turned OFF to engage overrun clutch. This will result in more effective engine brake during deceleration.


How to Perform Trouble Diagnosis for Quick and Accurate Repair


INTRODUCTION






The TCM receives a signal from the vehicle speed sensor, accelerator pedal position sensor or transmission range switch and provides shift control or lock-up control via A/T solenoid valves.
The TCM also communicates with the ECM by means of a signal sent from sensing elements used with the OBD-related parts of the
A/T system for malfunction-diagnostic purposes. The TCM is capable of diagnosing malfunctioning parts while the ECM can store malfunctions in its memory.
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 malfunction that occurs intermittently rather than continuously. Most intermittent malfunctions 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 malfunctions. A
road test with CONSULT or a circuit tester connected should be performed. Follow the "WORK FLOW" .
Before undertaking actual checks, take a few minutes to talk with a customer who approaches with a driveability complaint. The customer can supply good information about such malfunctions, especially intermittent ones. Find out what symptoms are present and under what conditions they occur. A "DIAGNOSTIC WORKSHEET"
like the example ("DIAGNOSTIC WORKSHEET" ) should be used.
Start your diagnosis by looking for "conventional" malfunctions first.
This will help troubleshoot driveability malfunctions on an electronically controlled engine vehicle.





Also check related Service bulletins for information.

WORK FLOW

A good understanding of the malfunction conditions can make troubleshooting faster and more accurate. In general, each customer feels differently about a malfunction. It is important to fully understand the symptoms or conditions for a customer complaint.
Make good use of the two sheets provided, "Information from customer" and "Diagnostic Worksheet Chart" , to perform the best troubleshooting possible.
Work Flow Chart











DIAGNOSTIC WORKSHEET

Information from Customer
-WHAT..... Vehicle & A/T model
-WHEN..... Date, Frequencies
-WHERE..... Road conditions
-HOW..... Operating conditions, Symptoms





Diagnostic Worksheet Chart

















A/T Electrical Parts Location













Circuit Diagram








Inspections Before Trouble Diagnosis


A/T FLUID CHECK

Fluid Leakage and Fluid Level Check
Check fluid leakage and check the fluid level. Checking.
Fluid Condition Check
Check the A/T fluid condition.











STALL TEST

Stall Test Procedure





1.Check ATF and engine oil levels. If necessary, add ATF and engine oil.
2.Drive vehicle for approximately 10 minutes or until ATF and engine oil reach operating temperature.
ATF operating temperature:50 - 80�C (122 - 176�F)





3.Set parking brake and block wheels.
4.Install a tachometer where it can be seen by driver during test.
-It is good practice to mark the point of specified engine rpm on indicator.





5.Start engine, apply foot brake, and place selector lever in "D"
position.





6.Accelerate to wide open throttle gradually while applying foot brake.
7.Quickly note the engine stall revolution and immediately release throttle.

CAUTION:
Do not hold down the accelerator pedal for more than 5 seconds during this test.

Stall revolution:Stall Speed





8.Move selector lever to "N" position.
9.Cool off ATF.

CAUTION:
Run the engine at idle for at least 1 minute.
10.Repeat steps 6 through 9 with selector lever in "2", "1" and "R"
positions.
Judgement of Stall Test
The test result and possible damaged components relating to each result are shown in the illustrations on next page.
In order to pinpoint the possible damaged components, refer to, "How to Perform Trouble Diagnosis for
Quick and Accurate Repair".
NOTE:
Stall revolution is too high in "D", "2", or "1" position:
- Slippage occurs in 1GR but not in 2GR and 3GR. ..... Low one-way clutch slippage
- Slippage occurs in the following gears:
1GR through 3GR in "D" position and engine brake functions with OD OFF. (OD OFF indicator lamp is on.)
1GR and 2GR in "2" 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 "R" position:
- Engine brake does not function in "1" position. ..... Low & reverse brake slippage
- Engine brake functions in "1" position. ..... Reverse clutch slippage
Stall revolution within specifications:
- Vehicle does not achieve speed of more than 80 km/h (50 MPH). ..... One-way clutch seizure in torque converter housing

CAUTION:
Be careful because automatic fluid temperature increases abnormally:
- Slippage occurs in 3GR and 4GR in "D" position. ..... High clutch slippage
- Slippage occurs in 2GR and 4GR in "D" position. ..... Brake band slippage
- Engine brake does not function in 2GR and 3GR in "D" position, 2GR in "2" position, and 1GR in "1" position with OD OFF. (OD OFF indicator lamp is on.) ..... Overrun clutch slippage
Stall revolution less than specifications:
- Poor acceleration during starts. ..... One-way clutch seizure in torque converter






LINE PRESSURE TEST

Line Pressure Test Ports





Location of line pressure test ports are shown in the figure.
-Always replace pressure plugs as they are self-sealing bolts.
Line Pressure Test Procedure





1.Check ATF and engine oil levels. If necessary, add ATF or engine oil.
2.Drive vehicle for approx. 10 minutes or until engine oil and ATF
reach operating temperature.
ATF operating temperature:50 - 80�C (122 -176�F)





3.Install oil pressure gauge to corresponding line pressure test port.





4.Set parking brake and block wheels.





5.Start engine and measure line pressure at idle and stall speed.

CAUTION:
- Keep the brake pedal pressed all the way down during measurement.
- When measuring the line pressure at the stall speed, refer to "STALL TEST".
Line Pressure





Judgement of Line Pressure Test







Road Test


DESCRIPTION






- The purpose of the test is to determine overall performance of A/T
and analyze causes of malfunctions.
- The road test consists of the following three parts:
1.Check before engine is started.
2.Check at idle.
3.Cruise test
- Inspection all the item from Part 1 to Part 3.





- Before road test, familiarize yourself with all test procedures and items to check.
- Test all inspection items until the symptom is uncovered. Include
NG items in "Diagnostic Worksheet Chart". Perform a diagnosis of the NG items after the completion of all the road tests.


Check Before Engine Is Started


1. CHECK OD OFF INDICATOR LAMP






1.Park vehicle on flat surface.
2.Move selector lever to "P" position.
3.Turn ignition switch OFF. Wait at least 5 seconds.





4.Turn ignition switch ON. (Do not start engine.)
Does OD OFF indicator lamp come on for about 2 seconds?
YES- 1.Turn ignition switch OFF.
2.Perform self-diagnosis and note NG items.
, .
3.Go to .
NO- Stop "Road Test". "OD OFF Indicator Lamp Does Not Come On" .


Check at Idle


1. CHECK ENGINE START

1.Park vehicle on flat surface.
2.Turn ignition switch ON. (Do not start engine.)





3.Move selector lever to "P" or "N" position.
4.Turn ignition switch to "START" position.
Is engine started?
YES- GO TO 2.
NO- - Stop "Road Test". Mark the box on the "Diagnostic
Worksheet Chart".
- Go to P" and
"N" Position" .

2. CHECK ENGINE START

1.Turn ignition switch ON. (Do not start engine.)





2.Move selector lever to "R", "D", "2" or "1" position.
3.Turn ignition switch to "START" position.
Is engine started?
YES- - Stop "Road Test". Mark the box on the "Diagnostic
Worksheet Chart".
- Go to P" and
"N" Position" .
- Continue "Road Test".
NO- GO TO 3.

3. CHECK VEHICLE MOVE






1.Move selector lever to "P" position.
2.Turn ignition switch OFF.
3.Release parking brake.





4.Push vehicle forward or backward.
Does vehicle move when it is pushed forward or backyard?
YES- - Mark the box on the "Diagnostic Worksheet Chart".
- Go to P" Position, Vehicle Moves Forward or Backward When Pushed" .
- Continue "Road Test".
NO- GO TO 4.

4. CHECK VEHICLE MOVE

1.Apply parking brake.
2.Start engine.





3.Move selector lever to "N" position.
4.Release parking brake.
Does vehicle move forward or backward?
YES- - Mark the box on the "Diagnostic Worksheet Chart".
- Go to N" Position, Vehicle Moves" .
- Continue "Road Test".
NO- GO TO 5.

5. CHECK SHIFT SHOCK






1.Apply foot brake.





2.Move selector lever to "R" position.
Is there large shock when changing from "N" to "R" position?
YES- - Mark the box on the "Diagnostic Worksheet Chart".
- N" --> "R" Position" .
- Continue "Road Test".
NO- GO TO 6.

6. CHECK VEHICLE MOVE






Release foot brake for several seconds.
Does vehicle creep backward when foot brake is released?
YES- GO TO 7.
NO- - Mark the box on the "Diagnostic Worksheet Chart".
- Go to , "Vehicle Does Not Creep Backward in "R" Position" .
- Continue "Road Test".

7. CHECK VEHICLE MOVE






Move selector lever to "D", "2" and "1" positions and check if vehicle creeps forward.
Does vehicle creep forward in all three positions?
YES- Go to .
NO- - Mark the box on the "Diagnostic Worksheet Chart".
- Go to , "Vehicle Does Not Creep Forward in "D", "2" or "1" Position" .
- Continue "Road Test".


Cruise Test - Part 1

1 ) POSITION

1. CHECK STARTING GEAR (D

1.Drive vehicle for approximately 10 minutes to warm engine oil and ATF up to operating temperature.
ATF operating temperature:50 - 80�C (122 - 176�F)
2.Park vehicle on flat surface.





3.Push overdrive control switch. (OD OFF indicator lamp is off.)
4.Move selector lever to "P" position.
5.Start engine.





6.Move selector lever to "D" position.





7.Accelerate vehicle by constantly depressing accelerator pedal half-way.
Read gear position. .
Does vehicle start from D1 ?
YES- GO TO 2.
NO- - Mark the box on the "Diagnostic Worksheet Chart".
- Go to .
- Continue "Road Test".
1 TO D2 )

2. CHECK SHIFT-UP (D

Check shift-up (D1 to D2 ).
Specified speed when shifting from D1 to D2. .





Read gear position, throttle opening and vehicle speed.
.

Does A/T shift from D1 to D2 at the specified speed?
YES- GO TO 3.
NO- - Mark the box on the "Diagnostic Worksheet Chart".
- Go to, "A/T Does Not Shift: D1 --> D2 or Does
Not Kickdown: D4--> D2" .
- Continue "Road Test".
2 TO D3 )

3. CHECK SHIFT-UP (D

Check shift-up (D2 to D3 ).
Specified speed when shifting from D2 to D3. .





Read gear position, throttle opening and vehicle speed.
.

Does A/T shift from D2 to D3 at the specified speed?
YES- GO TO 4.
NO- - Mark the box on the "Diagnostic Worksheet Chart".
- Go to {[AT-187, "A/T Does Not Shift: D2--> D3"].
- Continue "Road Test".
3 TO D4 )

4. CHECK SHIFT-UP (D

Check shift-up (D3 to D4 ).
Specified speed when shifting from D3 to D4. .





Read gear position, throttle opening and vehicle speed.
.

Does A/T shift from D3 to D4 at the specified speed?
YES- GO TO 5.
NO- - Mark the box on the "Diagnostic Worksheet Chart".
- Go to {[AT-189, "A/T Does Not Shift: D3--> D4"].
- Continue "Road Test".
4 TO D4 L/U)

5. CHECK LOCK-UP (D

Check lock-up (D4 to D4 L/U).
Specified speed when lock-up occurs. .





Read vehicle speed, throttle opening when lock-up duty becomes 94%. .
Does A/T perform lock-up at the specified speed?
YES- GO TO 6.
NO- - Mark the box on the "Diagnostic Worksheet Chart".
- Go to A/T Does Not Perform Lock-Up .
- Continue "Road Test".

6. CHECK LOCK-UP HOLD

Check lock-up hold.
When lock-up duty becomes 94%. .
Does A/T hold lock-up condition for more than 30 seconds?
YES- GO TO 7.
NO- - Mark the box on the "Diagnostic Worksheet Chart".
- Go to A/T Does Not Hold Lock-Up Condition .
- Continue "Road Test".
4 L/U TO D4 )

7. CHECK SHIFT-DOWN (D

Release accelerator pedal.
When lock-up duty becomes 4%. .
Is lock-up released when accelerator pedal is released?
YES- GO TO 8.
NO- - Mark the box on the "Diagnostic Worksheet Chart".
- Go to Lock-Up Is Not Released .
- Continue "Road Test".
4 TO D3 )

8. CHECK SHIFT-DOWN (D






Decelerate vehicle by applying foot brake lightly.
Read gear position and engine speed. .
Does engine speed return to idle smoothly when A/T is shifted from
D4 to D3 ?
YES- 1.Stop vehicle.
2.Go to .
NO- - Mark the box on the "Diagnostic Worksheet Chart".
- Go to, "Engine Speed Does Not Return to Idle (Light Braking D4--> D3)" .
- Continue "Road Test".


Cruise Test - Part 2

1 ) POSITION

1. CHECK STARTING GEAR (D

1.Push overdrive control switch. (OD OFF indicator lamp is off.)
2.Move selector lever to "D" position.





3.Accelerate vehicle by half throttle again.
Read gear position. .
Does vehicle start from D1 ?
YES- GO TO 2.
NO- - Mark the box on the "Diagnostic Worksheet Chart".
- Go to .
- Continue "Road Test".
3 TO D4 TO D2 )

2. CHECK SHIFT-UP AND SHIFT-DOWN (D

1.Accelerate vehicle to 80 km/h (50 MPH) as shown in the figure.





2.Release accelerator pedal and then quickly depress it fully.
Read gear position and throttle opening. .
Does A/T shift from D4 to D 2 as soon as accelerator pedal is depressed fully?
YES- GO TO 3.
NO- - Mark the box on the "Diagnostic Worksheet Chart".
- Go to, "A/T Does Not Shift: D1--> D2or Does
Not Kickdown: D4--> D2" .
- Continue "Road Test".
2 TO D3 )

3. CHECK SHIFT-UP (D

Check shift-up (D2 to D3 )
Specified speed when shifting from D2 to D3 . .





Read gear position, throttle opening and vehicle speed.
.

Does A/T shift from D2 to D3 at the specified speed?
YES- GO TO 4.
NO- - Mark the box on the "Diagnostic Worksheet Chart".
- Go to {[AT-187, "A/T Does Not Shift: D2--> D3"]} .
- Continue "Road Test".
3 TO D4 ) AND ENGINE BRAKE

4. CHECK SHIFT-UP (D

Release accelerator pedal after shifting from D2 to D3 .





Read gear position, throttle opening and vehicle speed.
.

Does A/T shift from D3 to D4 and does vehicle decelerate by engine brake?
YES- 1.Stop vehicle.
2.Go to .
NO- - Mark the box on the "Diagnostic Worksheet Chart".
- Go to {[AT-189, "A/T Does Not Shift: D3--> D4"].
- Continue "Road Test".


Cruise Test - Part 3

4 TO D3 )

1. CHECK SHIFT-DOWN (D

1.Push overdrive control switch. (OD OFF indicator lamp is off.)
2.Move selector lever to "D" position.





3.Accelerate vehicle using half throttle to D4 .





4.Release accelerator pedal.





5.Push overdrive control switch. (OD OFF indicator lamp is on.)
Read gear position and vehicle speed. .
Does A/T shift from D4 to D3 (OD OFF)?
YES- GO TO 2.
NO- - Mark the box on the "Diagnostic Worksheet Chart".
- Go to, "A/T Does Not Shift: D4--> D3, When OD
OFF" .
- Continue "Road Test".

2. CHECK ENGINE BRAKE






Check engine brake.
Does vehicle decelerate by engine brake?
YES- GO TO 3.
NO- - Mark the box on the "Diagnostic Worksheet Chart".
- Go to, "Vehicle Does Not Decelerate by
Engine Brake" .
- Continue "Road Test".
3 TO 22 )

3. CHECK SHIFT-DOWN (D






Move selector lever from "D" to "2" position while driving in D3 (OD
OFF).
Read gear position. .
Does A/T shift from D3 (OD OFF) to 22 ?
YES- GO TO 4.
NO- - Mark the box on the "Diagnostic Worksheet Chart".
- Go to, "A/T Does Not Shift: D3--> 22, When
Selector Lever "D" --> "2" Position" .
- Continue "Road Test".

4. CHECK ENGINE BRAKE






Check engine brake.
Does vehicle decelerate by engine brake?
YES- GO TO 5.
NO- - Mark the box on the "Diagnostic Worksheet Chart".
- Go to, "Vehicle Does Not Decelerate by
Engine Brake" .
- Continue "Road Test".
2 TO 11 )

5. CHECK SHIFT-DOWN (2






Move selector lever from "2" to "1" position while driving in 22 .
Read gear position. .
Does A/T shift from 22 to 11 position?
YES- GO TO 6.
NO- - Mark the box on the "Diagnostic Worksheet Chart".
- Go to, "A/T Does Not Shift: 22--> 1 1, When
Selector Lever "2" --> "1" Position" .
- Continue "Road Test".

6. CHECK ENGINE BRAKE






Check engine brake.
Does vehicle decelerate by engine brake?
YES- 1.Stop vehicle.
2.Perform self-diagnosis. , "Diagnosis
Procedure without CONSULT" .
NO- - Mark the box on the "Diagnostic Worksheet Chart".
- Go to, "Vehicle Does Not Decelerate by
Engine Brake" .
- Stop "Road Test".


Vehicle Speed at Which Gear Shifting Occurs






- At half throttle, the accelerator opening is 4/8 of the full opening.


Vehicle Speed at Which Lock-up Occurs/Releases