AT-44
TROUBLE DIAGNOSIS
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 sec-
onds during this test.
8. Move selector lever to “N” position.
9. Cool off ATF.
CAUTION:
Run engine at idle for at leas 1 minute.
10. Repeat steps 6 through 9 with selector lever in “3”, “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 AT- 3 7 , "
Work Flow Chart" .
NOTE:
Stall revolution is too high in “D”, “3”, “2”, or “1” position:
Slippage occurs in 1st gear but not in 2nd and 3rd gears. ..... Low one-way clutch slippage
Slippage occurs in the following gears:
1st through 3rd gears in “D” position and engine brake functions with selector lever set to “3” position.
1st and 2nd gears 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 since automatic fluid temperature increases abnormally.
Slippage occurs in 3rd and 4th gears in “D” position. ..... High clutch slippage
Slippage occurs in 2nd and 4th gear in “D” position. ..... Brake band slippage
Engine brake does not function in 2nd and 3rd gears in “D” position with 3rd position switch set to ON, 2nd
gear in “2” position, and 1st gear in “1” position. ..... Overrun clutch slippage
Stall revolution less than specifications:
Poor acceleration during starts. ..... One-way clutch seizure in torque converterStall revolution
For QR20DE engine models:
2,400 - 2,850 rpm
For VQ23DE engine models:
2,400 - 2,900 rpm
SAT514G
SCIA5704E
AT-46
TROUBLE DIAGNOSIS
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.
3. Install oil pressure gauge to corresponding line pressure test
port.
4. Set parking brake and block wheels.
SCIA3332E
ATF operating temperature: 50 - 80°C (122 -176°F)
SAT647B
SCIA4845E
SCIA7463E
TROUBLE DIAGNOSIS
AT-47
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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 line pressure at stall speed, refer to AT-
43, "STALL TEST" .
Line Pressure
Judgement of Line Pressure Test
SAT493G
Engine speed rpmLine pressure kPa (bar, kg/cm2 , psi)
“D”, “3”, “2” and “1” positions “R” position
Idle 500 (5.00, 5.1, 73) 778 (7.78, 7.9, 113)
Stall 1,233 (12.33, 12.6, 179) 1,918 (19.18, 19.6, 278)
Judgement Suspected parts
At idleLine pressure is low in all positions.
Oil pump wear
Control piston damage
Pressure regulator valve or plug sticking
Spring for pressure regulator valve damaged
Fluid pressure leakage between oil strainer and pressure regulator valve
Clogged strainer
Line pressure is low in particular posi-
tion.
Fluid pressure leakage between manual valve and particular clutch
For example, line pressure is:
− Low in “R” and “1” positions, but
− Normal in “D”, “3” and “2” positions.
Therefore, fluid leakage exists at or around low and reverse brake circuit.
Refer to AT-18, "
CLUTCH AND BAND CHART" .
Line pressure is high.
Accelerator pedal position signal malfunction
A/T fluid temperature sensor damaged
Line pressure solenoid valve sticking
Short circuit of line pressure solenoid valve circuit
Pressure modifier valve sticking
Pressure regulator valve or plug sticking
Open in dropping resistor circuit
At stall
speedLine pressure is low.
Accelerator pedal position signal malfunction
Line pressure solenoid valve sticking
Short circuit of line pressure solenoid valve circuit
Pressure regulator valve or plug sticking
Pressure modifier valve sticking
Pilot valve sticking
TROUBLE DIAGNOSIS
AT-49
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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 AT- 1 7 6 , "In “P” Position, Vehicle Moves Forward or Backward When Pushed" on
the AT- 3 8 , "
DIAGNOSTIC WORKSHEET" .
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 AT- 1 7 6 , "In “N” Position, Vehicle Moves" on the AT- 3 8 , "DIAGNOSTIC WORK-
SHEET" .
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 AT- 1 7 7 , "Large Shock. “N” → “R” Position" on the AT- 3 8 , "DIAGNOSTIC WORK-
SHEET" .
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 AT- 1 7 9 , "Vehicle Does Not Creep Backward in “R” Position" on the AT- 3 8 , "DIAG-
NOSTIC WORKSHEET" .
Continue “Road Test”.
7. CHECK VEHICLE MOVE
Move selector lever to “D”, “3”, “2” and “1” positions and check if vehicle creeps forward.
Does vehicle creep forward in all four positions?
YES >> Go to AT- 5 0 , "Cruise Test — Part 1" .
NO >>
Mark the box AT- 1 8 1 , "Vehicle Does Not Creep Forward in “D”, “3”, “2” or “1” Position" on the
AT- 3 8 , "
DIAGNOSTIC WORKSHEET" .
Continue “Road Test”.
TROUBLE DIAGNOSIS
AT-51
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5. CHECK LOCK-UP (D4 TO D4 L/U)
Check lock-up (D
4 to D4 L/U).
Specified speed when lock-up occurs (Throttle position: half throttle). Refer to AT- 5 4 , "
Vehicle Speed at When
Lock-up Occurs/Releases" .
Read vehicle speed, throttle opening when lock-up duty becomes 94%. Refer to AT- 7 0 , "
DATA
MONITOR MODE" .
Does A/T perform lock-up at specified speed?
YES >> GO TO 6.
NO >>
Mark the box AT- 1 9 1 , "A/T Does Not Perform Lock-up" on the AT- 3 8 , "DIAGNOSTIC WORK-
SHEET" .
Continue “Road Test”.
6. CHECK LOCK-UP HOLD
Check lock-up hold.
When lock-up duty becomes 94%. Refer to AT- 7 0 , "
DATA MONITOR MODE" .
Does A/T hold lock-up condition for more than 30 seconds?
YES >> GO TO 7.
NO >>
Mark the box AT- 1 9 3 , "A/T Does Not Hold Lock-up Condition" on the AT- 3 8 , "DIAGNOSTIC
WORKSHEET" .
Continue “Road Test”.
7. CHECK SHIFT-DOWN (D4 L/U TO D4 )
Release accelerator pedal.
When lock-up duty becomes 4%. Refer to AT- 7 0 , "
DATA MONITOR MODE" .
Is lock-up released when accelerator pedal is released?
YES >> GO TO 8.
NO >>
Mark the box AT- 1 9 5 , "Lock-up Is Not Released" on the AT- 3 8 , "DIAGNOSTIC WORKSHEET"
.
Continue “Road Test”.
8. CHECK SHIFT-DOWN (D4 TO D3 )
Decelerate vehicle by applying foot brake lightly.
Read gear position and engine speed. Refer to AT- 7 0 , "
DATA MONITOR MODE" .
Does engine speed return to idle smoothly when A/T is shifted from D
4 to D3 ?
YES >> 1. Stop vehicle.
2. Go to AT- 5 1 , "
Cruise Test — Part 2" .
NO >>
Mark the box AT- 1 9 5 , "Engine Speed Does Not Return To Idle (Light Braking D4 → D3 )" on the
AT- 3 8 , "
DIAGNOSTIC WORKSHEET" .
Continue “Road Test”.
Cruise Test — Part 2BCS00107
1. CHECK STARTING GEAR (D1 ) POSITION
1. Move selector lever to “D” position.
2. Accelerate vehicle by half throttle again.
Read gear position. Refer to AT- 7 0 , "
DATA MONITOR MODE" .
Does vehicle start from D
1 ?
YES >> GO TO 2.
NO >>
Mark the box AT- 1 8 2 , "Vehicle Cannot Be Started From D1" on the AT- 3 8 , "DIAGNOSTIC
WORKSHEET" .
Continue “Road Test”.
AT-52
TROUBLE DIAGNOSIS
2. CHECK SHIFT-UP AND SHIFT-DOWN (D3 TO D4 TO D2 )
1. Accelerate vehicle to 80 km/h (50 MPH).
2. Release accelerator pedal and then quickly depress it fully.
Read gear position and throttle opening. Refer to AT- 7 0 , "
DATA MONITOR MODE" .
Does A/T shift from D
4 to D2 as soon as accelerator pedal is depressed fully?
YES >> GO TO 3.
NO >>
Mark the box AT- 1 8 4 , "A/T Does Not Shift: D1 → D2 or Does Not Kickdown: D4 → D2" on the
AT- 3 8 , "
DIAGNOSTIC WORKSHEET" .
Continue “Road Test”.
3. CHECK SHIFT-UP (D2 TO D3 )
Check shift-up (D
2 to D3 )
Specified speed when shifting from D
2 to D3 (Throttle position: full throttle). Refer to AT- 5 4 , "Vehicle Speed
Which Gear Shifting Occurs" .
Read gear position, throttle opening and vehicle speed. Refer to AT- 7 0 , "
DATA MONITOR MODE" .
Does A/T shift from D
2 to D3 at the specified speed?
YES >> GO TO 4.
NO >>
Mark the box AT- 1 8 6 , "A/T Does Not Shift: D2 → D3" on the AT- 3 8 , "DIAGNOSTIC WORK-
SHEET" .
Continue “Road Test”.
4. CHECK SHIFT-UP (D3 TO D4 ) AND ENGINE BRAKE
Release accelerator pedal after shifting from D
2 to D3 .
Read gear position, throttle opening and vehicle speed. Refer to AT- 7 0 , "
DATA MONITOR MODE" .
Does A/T shift from D
3 to D4 and does vehicle decelerate by engine brake?
YES >> 1. Stop vehicle.
2. Go to AT- 5 2 , "
Cruise Test — Part 3" .
NO >>
Mark the box AT- 1 8 8 , "A/T Does Not Shift: D3 → D4" on the AT- 3 8 , "DIAGNOSTIC WORK-
SHEET" .
Continue “Road Test”.
Cruise Test — Part 3BCS00108
1. CHECK SHIFT-DOWN (D4 TO 33 )
1. More selector lever to “D” position.
2. Accelerate vehicle using half-throttle to D
4 .
3. Release accelerator pedal.
4. Move gear selector lever from “D” position to “3” position while driving in D
4 .
Read gear position. Refer to AT- 7 0 , "
DATA MONITOR MODE" .
Does A/T shift from D
4 to 33 ?
YES >> GO TO 2.
NO >>
Mark the box AT- 1 9 7 , "A/T Does Not Shift: D4 → 33 , When A/T Selector Lever “D” → “3”" on
the AT- 3 8 , "
DIAGNOSTIC WORKSHEET" .
Continue “Road Test”.
TROUBLE DIAGNOSIS
AT-53
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2. CHECK ENGINE BRAKE
Check engine brake.
Does vehicle decelerate by engine brake?
YES >> GO TO 3.
NO >>
Mark the box AT- 2 0 3 , "Vehicle Does Not Decelerate By Engine Brake (D4 → 33 )" on the AT-
38, "DIAGNOSTIC WORKSHEET" .
Go to AT- 2 0 3 , "Vehicle Does Not Decelerate By Engine Brake (D4 → 33 )" .
Continue “Road Test”.
3. CHECK SHIFT-DOWN (33 TO 22 )
Move selector lever from “3” to “2” position while driving in 3
3 .
Read gear position. Refer to AT- 7 0 , "
DATA MONITOR MODE" .
Does A/T shift from 3
3 to 22 ?
YES >> GO TO 4.
NO >>
Mark the box AT- 1 9 8 , "A/T Does Not Shift: 33 → 22 , When Selector Lever “3” → “2” Position"
on the AT- 3 8 , "DIAGNOSTIC WORKSHEET" .
Continue “Road Test”.
4. CHECK ENGINE BRAKE
Check engine brake.
Does vehicle decelerate by engine brake?
YES >> GO TO 5.
NO >>
Mark the box AT- 2 0 5 , "Vehicle Does Not Decelerate By Engine Brake (33 → 22 )" on the AT- 3 8 ,
"DIAGNOSTIC WORKSHEET" .
Continue “Road Test”.
5. CHECK SHIFT-DOWN (22 TO 11 )
Move selector lever from “2” to “1” position while driving in 2
2 .
Read gear position. Refer to AT- 7 0 , "
DATA MONITOR MODE" .
Does A/T shift from 2
2 to 11 position?
YES >> GO TO 6.
NO >>
Mark the box AT- 2 0 0 , "A/T Does Not Shift: 22 → 11 , When Selector Lever “2” → “1” Position"
on the AT- 3 8 , "DIAGNOSTIC WORKSHEET" .
Continue “Road Test”.
6. CHECK ENGINE BRAKE
Check engine brake.
Does vehicle decelerate by engine brake?
YES >> 1. Stop vehicle.
2. Perform self-diagnosis. Refer to AT- 6 9 , "
SELF-DIAGNOSTIC RESULT MODE" , AT- 7 6 , "Diag-
nostic Procedure Without CONSULT-II" .
NO >>
Mark the box AT- 2 0 8 , "Vehicle Does Not Decelerate By Engine Brake (22 → 11 )" on the AT- 3 8 ,
"DIAGNOSTIC WORKSHEET" .
Continue “Road Test”.
TROUBLE DIAGNOSIS
AT-55
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Symptom ChartBCS0010B
Numbers are arranged in order of inspection.
Perform inspections starting with number one and work up.
Items Symptom Condition Diagnostic item Reference page
No Lock-up
Engagement/
TCC InoperativeTorque converter
is not locked up.ON vehicle1. Accelerator pedal position sensor
EC-272
*1, EC-652*2
2. Vehicle speed sensor·A/T (Revolution
sensor) and vehicle speed sensor·MTRAT- 8 0, AT- 8 6
3. PNP switchAT- 1 6 1
4. Engine speed signalAT- 11 6
5. A/T fluid temperature sensorAT- 11 0
6. Line pressure testAT- 4 6
7. Torque converter clutch solenoid valveAT- 1 0 5
8. Control valve assemblyAT- 2 2 5
OFF vehicle 9. Torque converterAT- 2 5 5
Torque converter
clutch piston slip.ON vehicle1. A/T fluid levelAT- 1 4
2. Accelerator pedal position sensor
EC-272*1, EC-652*2
3. Line pressure testAT- 4 6
4. Torque converter clutch solenoid valveAT- 1 0 5
5. Line pressure solenoid valveAT- 1 2 6
6. Control valve assemblyAT- 2 2 5
OFF vehicle 7. Torque converterAT- 2 5 5
Lock-up point is
extremely high or
low.ON vehicle1. Accelerator pedal position sensor
EC-272
*1, EC-652*2
2. Vehicle speed sensor·A/T (Revolution
sensor) and vehicle speed sensor·MTRAT- 8 0, AT- 8 6
3. Torque converter clutch solenoid valveAT- 1 0 5
4. Control valve assemblyAT- 2 2 5
Shift ShockSharp shock in
shifting from “N”
to “D” position.ON vehicle1. Engine idle speed
EC-45
*1, EC-387*2
2. Accelerator pedal position sensor
EC-272*1, EC-652*2
3. Line pressure testAT- 4 6
4. A/T fluid temperature sensorAT- 11 0
5. Engine speed signalAT- 11 6
6. Line pressure solenoid valveAT- 1 2 6
7. Control valve assemblyAT- 2 2 5
8. N-D accumulatorAT- 2 2 5
OFF vehicle 9. Forward clutchAT- 3 0 7
Too sharp a
shock in change
from D
1 to D2 .ON vehicle1. Accelerator pedal position sensor
EC-272
*1, EC-652*2
2. Line pressure testAT- 4 6
3. Accumulator servo releaseAT- 2 2 5
4. Control valve assemblyAT- 2 2 5
5. A/T fluid temperature sensorAT- 11 0
OFF vehicle 6. Brake bandAT- 3 2 9