SAT015J
Overrun Clutch Solenoid Valve ControlNJAT0015S0402The overrun clutch solenoid valve is operated by an ON-OFF sig-
nal transmitted by the TCM to provide overrun clutch control
(engine brake control).
When this solenoid valve is ªONº, the pilot pressure drain port
closes. When it is ªOFFº, the drain port opens.
During the solenoid valve ªONº pilot pressure is applied to the end
face of the overrun clutch control valve.
SAT016J
Overrun Clutch Control Valve OperationNJAT0015S0403When the solenoid valve is ªONº, pilot pressure is applied to the
overrun clutch control valve. This pushes up the overrun clutch
control valve. The line pressure is then shut off so that the clutch
does not engage.
When the solenoid valve is ªOFFº, pilot pressure is not generated.
At this point, the overrun clutch control valve moves downward by
spring force. As a result, overrun clutch operation pressure is pro-
vided by the overrun clutch reducing valve. This causes the over-
run clutch to engage.
In the 1 position, the overrun clutch control valve remains pushed
down so that the overrun clutch is engaged at all times.
Control ValveNJAT0016FUNCTION OF CONTROL VALVESNJAT0016S01
Valve name Function
Pressure regulator valve, plug
and sleeveRegulates oil discharged from the oil pump to provide optimum line pressure for all driving
conditions.
Pressure modifier valve and
sleeveUsed as a signal supplementary valve to the pressure regulator valve. Regulates pressure-
modifier pressure (signal pressure) which controls optimum line pressure for all driving condi-
tions.
Pilot valve Regulates line pressure to maintain a constant pilot pressure level which controls lock-up
mechanism, overrun clutch, shift timing.
Accumulator control valve Regulates accumulator back-pressure to pressure suited to driving conditions.
Manual valve Directs line pressure to oil circuits corresponding to select positions.
Hydraulic pressure drains when the shift lever is in Neutral.
Shift valve A Simultaneously switches four oil circuits using output pressure of shift solenoid valve A to
meet driving conditions (vehicle speed, throttle opening, etc.).
Provides automatic downshifting and up-shifting (1st®2nd®3rd®4th gears/4th®3rd®
2nd®1st gears) in combination with shift valve B.
OVERALL SYSTEM
Control Mechanism (Cont'd)
AT-37
SAT767B
A/T Fluid CheckNJAT0025FLUID LEAKAGE CHECKNJAT0025S011. 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.
SAT288G
4. Check for fresh leakage.
SAT638A
FLUID CONDITION CHECKNJAT0025S02
Fluid color Suspected problem
Dark or black with burned odor Wear of frictional material
Milky pink Water contamination Ð Road water
entering through filler tube or breather
Varnished fluid, light to dark brown
and tackyOxidation Ð Over or under filling, Ð
Overheating
FLUID LEVEL CHECKNJAT0025S03Refer to ªChecking A/T Fluidº, AT-15.
SAT647B
Stall TestNJAT0026STALL TEST PROCEDURENJAT0026S011. Check A/T fluid and engine oil levels. If necessary, add.
2. Drive vehicle for approx. 10 minutes or until fluid and oil reach
operating temperature.
ATF operating temperature:
50 - 80ÉC (122 - 176ÉF)
TROUBLE DIAGNOSIS Ð BASIC INSPECTION
A/T Fluid Check
AT-80
SAT561J
Line Pressure TestNJAT0027LINE PRESSURE TEST PORTSNJAT0027S01Location of line pressure test ports are shown in the illustration.
+Always replace pressure plugs as they are self-sealing
bolts.
SAT647B
LINE PRESSURE TEST PROCEDURENJAT0027S021. Check A/T fluid and engine oil levels. If necessary, add fluid or
oil.
2. Drive vehicle for approx. 10 minutes or until engine oil and ATF
reach operating temperature.
ATF operating temperature:
50 - 80ÉC (122 - 176ÉF)
UAT008
3. Install pressure gauge to corresponding line pressure port.
UAT008
4. Set parking brake and block wheels.
+Continue to depress brake pedal fully while line pressure
test is being performed at stall speed.
SAT493G
5. Start engine and measure line pressure at idle and stall speed.
+When measuring line pressure at stall speed, follow the
stall test procedure.
Line pressure: Refer to SDS, AT-473.
TROUBLE DIAGNOSIS Ð BASIC INSPECTION
Line Pressure Test
AT-84
Symptom ChartNJAT0029Numbers are arranged in order of inspection.
Perform inspections starting with number one and work up.
Symptom Condition Diagnostic ItemReference Page
General and
except for
Euro-OBDEURO-OBD
Engine cannot start in ªPº and ªNº
positions.
AT-299ON vehicle1. Ignition switch and starterEL-10, ªPOWER SUPPLY
ROUTINGº and SC-13,
ªSTARTING SYSTEMº
2. Control cable adjustment AT-352¬
3. PNP switch adjustment AT-352¬
Engine starts in position other than
ªNº and ªPº positions.
AT-299ON vehicle1. Control cable adjustment AT-352¬
2. PNP switch adjustment AT-352¬
Transaxle noise in ªPº and ªNº
positions.ON vehicle1. Fluid level AT-80¬
2. Line pressure test AT-84¬
3. Throttle position sensor (Adjustment)EC-207,
ªDTC P0120
THROTTLE
POSITION
SENSORºEC-207,
ªDTC P0120
THROTTLE
POSITION
SENSORº
4. Vehicle speed sensor´A/T (Revolution
sensor) and vehicle speed sensor´MTRAT-126,
AT-131AT-195,
AT-281
5. Engine speed signal AT-172 AT-200
OFF vehicle6. Oil pump AT-384¬
7. Torque converter AT-366¬
Vehicle moves when changing into
ªPº position, or parking gear does
not disengage when shifted out of
ªPº position.
AT-300ON vehicle 1. Control cable adjustment AT-352¬
OFF vehicle 2. Parking componentsAT-361,
AT-362AT-362
Vehicle runs in ªNº position.
AT-301ON vehicle 1. Control cable adjustment AT-352¬
OFF vehicle2. Forward clutch AT-412¬
3. Reverse clutch AT-403¬
4. Overrun clutch AT-412¬
Vehicle will not run in ªRº position
(but runs in ªDº, ª2º and ª1º posi-
tions). Clutch slips.
Very poor acceleration.
AT-305ON vehicle1. Control cable adjustment AT-352¬
2. Line pressure test AT-84¬
3. Line pressure solenoid valve AT-176 AT-239
4. Control valve assembly AT-351¬
OFF vehicle5. Reverse clutch AT-403¬
6. High clutch AT-407¬
7. Forward clutch AT-412¬
8. Overrun clutch AT-412¬
9. Low & reverse brake AT-419¬
TROUBLE DIAGNOSIS Ð GENERAL DESCRIPTION
Symptom Chart
AT-105
Symptom Condition Diagnostic ItemReference Page
General and
except for
Euro-OBDEURO-OBD
Clutches or brakes slip somewhat
in starting.ON vehicle1. Fluid level AT-80¬
2. Control cable adjustment AT-352¬
3. Throttle position sensor (Adjustment)EC-207,
ªDTC P0120
THROTTLE
POSITION
SENSORºEC-207,
ªDTC P0120
THROTTLE
POSITION
SENSORº
4. Line pressure test AT-84¬
5. Line pressure solenoid valve AT-176 AT-239
6. Control valve assembly AT-351¬
7. Accumulator N-D AT-351¬
OFF vehicle8. Forward clutch AT-412¬
9. Reverse clutch AT-403¬
10. Low & reverse brake AT-419¬
11. Oil pump AT-384¬
12. Torque converter AT-366¬
Excessive creep. ON vehicle 1. Engine idling rpmEC-43, ªIdle
Speed and
Ignition Tim-
ingºEC-43, ªIdle
Speed and
Ignition Tim-
ingº
No creep at all.
AT-305 and AT-308ON vehicle1. Fluid level AT-80¬
2. Line pressure test AT-84¬
3. Control valve assembly AT-351¬
OFF vehicle4. Forward clutch AT-412¬
5. Oil pump AT-384¬
6. Torque converter AT-366¬
Failure to change gear from ªD
1º
to ªD
2º.ON vehicle1. PNP switch adjustment AT-352¬
2. Control cable adjustment AT-352¬
3. Shift solenoid valve A AT-142 AT-246
4. Control valve assembly AT-351¬
5. Vehicle speed sensor´A/T (Revolution
sensor) and vehicle speed sensor´MTRAT-126,
AT-131AT-195,
AT-281
OFF vehicle 6. Brake band AT-437¬
TROUBLE DIAGNOSIS Ð GENERAL DESCRIPTION
Symptom Chart (Cont'd)
AT-107
Symptom Condition Diagnostic ItemReference Page
General and
except for
Euro-OBDEURO-OBD
Maximum speed not attained.
Acceleration poor.ON vehicle1. Fluid level AT-80¬
2. PNP switch adjustment AT-352¬
3. Shift solenoid valve A AT-142 AT-246
4. Shift solenoid valve B AT-148 AT-252
5. Control valve assembly AT-351¬
OFF vehicle6. Reverse clutch AT-403¬
7. High clutch AT-407¬
8. Brake band AT-437¬
9. Low & reverse brake AT-419¬
10. Oil pump AT-384¬
11. Torque converter AT-366¬
Failure to change gear from ªD
4º
to ªD
3º.ON vehicle1. Fluid level AT-80¬
2. Throttle position sensor (Adjustment)EC-207,
ªDTC P0120
THROTTLE
POSITION
SENSORºEC-207,
ªDTC P0120
THROTTLE
POSITION
SENSORº
3. Overrun clutch solenoid valve AT-154 AT-268
4. Shift solenoid valve A AT-142 AT-246
5. Line pressure solenoid valve AT-176 AT-239
6. Control valve assembly AT-351¬
OFF vehicle7. Low & reverse brake AT-419¬
8. Overrun clutch AT-412¬
Failure to change gear from ªD
3º
to ªD
2º or from ªD4ºtoªD2º.ON vehicle1. Fluid level AT-80¬
2. Throttle position sensor (Adjustment)EC-207,
ªDTC P0120
THROTTLE
POSITION
SENSORºEC-207,
ªDTC P0120
THROTTLE
POSITION
SENSORº
3. Shift solenoid valve A AT-142 AT-246
4. Shift solenoid valve B AT-148 AT-252
5. Control valve assembly AT-351¬
OFF vehicle6. High clutch AT-407¬
7. Brake band AT-437¬
TROUBLE DIAGNOSIS Ð GENERAL DESCRIPTION
Symptom Chart (Cont'd)
AT - 111
Symptom Condition Diagnostic ItemReference Page
General and
except for
Euro-OBDEURO-OBD
Races extremely fast or slips in
changing from ªD
3ºtoªD2º when
depressing pedal.ON vehicle1. Fluid level AT-80¬
2. Throttle position sensor (Adjustment)EC-207,
ªDTC P0120
THROTTLE
POSITION
SENSORºEC-207,
ªDTC P0120
THROTTLE
POSITION
SENSORº
3. Line pressure test AT-84¬
4. Line pressure solenoid valve AT-176 AT-239
5. Control valve assembly AT-351¬
6. A/T fluid temperature sensor AT-165 AT-189
OFF vehicle7. Brake band AT-437¬
8. Forward clutch AT-412¬
9. High clutch AT-407¬
Races extremely fast or slips in
changing from ªD
4ºorªD3ºtoªD1º
when depressing pedal.ON vehicle1. Fluid level AT-80¬
2. Throttle position sensor (Adjustment)EC-207,
ªDTC P0120
THROTTLE
POSITION
SENSORºEC-207,
ªDTC P0120
THROTTLE
POSITION
SENSORº
3. Line pressure test AT-84¬
4. Line pressure solenoid valve AT-176 AT-239
5. Control valve assembly AT-351¬
OFF vehicle6. Forward clutch AT-412¬
7. Forward one-way clutch AT-423¬
8. Low one-way clutchAT-359,
AT-360AT-360
Vehicle will not run in any position.ON vehicle1. Fluid level AT-80¬
2. Control cable adjustment AT-352¬
3. Line pressure test AT-84¬
4. Line pressure solenoid valve AT-176 AT-239
OFF vehicle5. Oil pump AT-384¬
6. High clutch AT-407¬
7. Brake band AT-437¬
8. Low & reverse brake AT-419¬
9. Torque converter AT-366¬
10. Parking components AT-446¬
Transmission noise in ªDº, ª2º, ª1º
and ªRº positions.ON vehicle 1. Fluid level AT-80¬
OFF vehicle 2. Torque converter AT-366¬
TROUBLE DIAGNOSIS Ð GENERAL DESCRIPTION
Symptom Chart (Cont'd)
AT-114
Symptom Condition Diagnostic ItemReference Page
General and
except for
Euro-OBDEURO-OBD
Large shock changing from ª1
2ºto
ª1
1º in ª1º position.ON vehicle 1. Control valve assembly AT-351¬
OFF vehicle 2. Low & reverse brake AT-419¬
Transmission overheats.ON vehicle1. Fluid level AT-80¬
2. Engine idling rpmEC-43, ªIdle
Speed and
Ignition Tim-
ingºEC-43, ªIdle
Speed and
Ignition Tim-
ingº
3. Throttle position sensor (Adjustment)EC-207,
ªDTC P0120
THROTTLE
POSITION
SENSORºEC-207,
ªDTC P0120
THROTTLE
POSITION
SENSORº
4. Line pressure test AT-84¬
5. Line pressure solenoid valve AT-176 AT-239
6. Control valve assembly AT-351¬
OFF vehicle7. Oil pump AT-384¬
8. Reverse clutch AT-403¬
9. High clutch AT-407¬
10. Brake band AT-437¬
11. Forward clutch AT-412¬
12. Overrun clutch AT-412¬
13. Low & reverse brake AT-419¬
14. Torque converter AT-366¬
ATF shoots out during operation.
White smoke emitted from exhaust
pipe during operation.ON vehicle 1. Fluid level AT-80¬
OFF vehicle2. Reverse clutch AT-403¬
3. High clutch AT-407¬
4. Brake band AT-437¬
5. Forward clutch AT-412¬
6. Overrun clutch AT-412¬
7. Low & reverse brake AT-419¬
Offensive smell at fluid charging
pipe.ON vehicle 1. Fluid level AT-80¬
OFF vehicle2. Torque converter AT-366¬
3. Oil pump AT-384¬
4. Reverse clutch AT-403¬
5. High clutch AT-407¬
6. Brake band AT-437¬
7. Forward clutch AT-412¬
8. Overrun clutch AT-412¬
9. Low & reverse brake AT-419¬
TROUBLE DIAGNOSIS Ð GENERAL DESCRIPTION
Symptom Chart (Cont'd)
AT-116