Page 412 of 656

AUTOMATIC TRANSMISSION (4 A/T) 7B1-3
General Description
Item Specifications
Torque
converterType 3-element, 1-step, 2-phase type (with TCC (lock-up) mechanism)
Stall torque ratio 2.0
Oil pump Type Trochoid type oil pump
Drive system Engine driven
Gear
change
deviceType Forward 4-step, reverse 1-step planetary gear type
Shift position“P” range Gear in neutral, output shaft fixed, engine start
“R” range Reverse
“N” range Gear in neutral, engine start
“D” range
(O/D ON)Forward 1st ↔ 2nd ↔ 3rd ↔ 4th (O/D)
automatic gear change
“D” range
(O/D OFF)Forward 1st ↔ 2nd ↔ 3rd
automatic gear change
“2” range (Normal mode) Forward 1st ↔ 2nd ← 3rd auto-
matic gear change
(Power mode) Forward 2nd ← 3rd automatic gear
change and fixed at 2nd gear
“L” range Forward 1st ← 2nd ← 3rd reduction, and fixed at
1st gear
Gear
ratio1st
(low gear)2.826
2nd
(second gear)1.493
3rd
(top gear)1.000
4th
(overdrive gear)0.689
Reverse
(reverse gear2.703
Control elements Wet type multi-disc clutch ... 3 sets
Wet type multi-disc brake ... 4 sets
One-way clutch ... 3 sets
Transfer Hi : 1.000
Lo : 1.816 (4WD model only)
Final gear reduction
ratio (Differential)5.125
Lubrication Lubrication system Force feed system by oil pump
Cooling Cooling system Radiator assisted cooling (water-cooled)
Fluid used
An equivalent of DEXRON
III
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AUTOMATIC TRANSMISSION (4 A/T) 7B1-5
Automatic gear shift diagram
Automatic shift schedule as a result of shift control is shown below. In case that select lever is shifted to L at a
higher than 55 km/h or 34 mile/h speed, 2nd or 3rd gear is operated and then down shifts to 1st at a speed lower
than that. No up shift is available in L.
The same as, the select lever is shifted to 2 at a higher than 105 km/h (65 mile/h) speed, 3rd gear is operated
and then down shifts to 2nd at a speed lower than that.
[POWER MODE]
GEAR SHIFT DIAGRAM [A] AND TCC LOCK-UP DIAGRAM [B]
Shift
1 →
→→ → 22 →
→→ → 33 →
→→ → 44 →
→→ → 33 →
→→ → 22 →
→→ → 1
Throttle
openingFull throttle km/h (mile/h) 46
(29)93
(58)160
(100)150
(94)83
(52)36
(23)
Closed throttle km/h (mile/h) 16
(10)30
(19)45
(28)38
(16)24
(11)7
(4)
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7B1-6 AUTOMATIC TRANSMISSION (4 A/T)
[NORMAL MODE]
GEAR SHIFT DIAGRAM [A] AND TCC LOCK-UP DIAGRAM [B]
Shift
1 →
→→ → 22 →
→→ → 33 →
→→ → 44 →
→→ → 33 →
→→ → 22 →
→→ → 1
Throttle
openingFull throttle km/h (mile/h) 46
(29)93
(58)160
(100)150
(94)83
(52)36
(23)
Closed throttle km/h (mile/h) 11
(7)27
(17)40
(25)35
(22)21
(13)7
(4)
Page 424 of 656

AUTOMATIC TRANSMISSION (4 A/T) 7B1-15
Trouble Diagnosis Table 1
Trouble Diagnosis Table 2
TRANSMISSION FLUID
RUNNING CONDITION
4 Perform stall test, time rag test, line pressure test,
engine brake test and “P” range test referring to
“STALL TEST”, “LINE PRESSURE TEST”, “ENGINE
BRAKE TEST” and ““P” RANGE TEST” in this section.
Are the test results satisfactory?Go to Step 5. Proceed to “TROUBLE
DIAGNOSIS TABLE 3” in
this section.
5 Proceed to “TROUBLE DIAGNOSIS TABLE 2” in this
section.
Is trouble identified?Repair or replace
defective parts.Proceed to “TROUBLE
DIAGNOSIS TABLE 3” in
this section. Step Action Yes No
Condition Possible Cause Correction
TCC does not operateBrake pedal (stop lamp) switch or its circuit
faulty (H25 engine only)Refer to “DIAGNOSTIC FLOW
TABLE A-1” in this section.
4WD low switch or its circuit faulty
Engine coolant temp. sensor or its circuit faulty
Cruise control signal circuit faulty (if equipped)
Gear does not change
to 4thO/D off switch or its circuit faulty Refer to “DIAGNOSTIC FLOW
TABLE A-2” in this section.
4WD low switch or its circuit faulty
Engine coolant temp. sensor or its circuit faulty
Cruise control signal circuit faulty (if equipped)
Condition Possible Cause Correction
Low fluid pressureClogged oil pump strainer Wash strainer.
Malfunction of pressure regulator valve Overhaul valve body.
High fluid pressurePressure regulator valve Overhaul valve body.
Condition Possible Cause Correction
Unable to run in all
rangeRegulator valve stick Replace.
Clogged oil strainer Wash strainer.
Seized or broken planetary gear Repair or replace.
Faulty manual valve Replace.
Poor 1st speed run-
ning or excessive slip-
page in “D” or “2”Faulty 1–2 shift valve Replace.
Page 425 of 656

7B1-16 AUTOMATIC TRANSMISSION (4 A/T)
GEAR SHIFT
Trouble Diagnosis Table 3
TRANSMISSION FLUID
RUNNING CONDITION
Condition Possible Cause Correction
Poor 1–2 shift, exces-
sive slippageRegulator valve sticking Replace.
1–2 shift valve sticking Replace.
Shift solenoid valve-B sticking Replace.
Intermediate coast modulator valve sticking Replace.
Poor 2–3 shift, exces-
sive slippage2–3 shift valve sticking Replace.
Shift solenoid valve-A sticking Replace.
Poor start or surging
in “D” rangeRegulator valve sticking Replace.
Poor 3-4 shift, exces-
sive slippage3–4 shift valve sticking Replace.
Shift solenoid valve-B sticking Replace.
Excessive shock on
1–2 shiftRegulator valve sticking Replace.
Faulty accumulator, second brake piston Replace.
Excessive shock on
2–3 shiftRegulator valve sticking Replace.
Faulty accumulator, direct clutch piston Replace.
Excessive shock on
3–4 shiftRegulator valve sticking Replace.
Non operate lock-up
systemTCC (Lock-up) control valve sticking Replace.
Solenoid valve No.2 (TCC solenoid valve) stick-
ingReplace.
Condition Possible Cause Correction
Low fluid pressureLeakage from oil pressure circuit Overhaul.
Condition Possible Cause Correction
Unable to run in all
rangeWear in oil pump Replace.
Seizure in oil pump Replace.
Fluid pressure leakage to over drive clutch due
to wear of oil pump bushingReplace.
Faulty in torque converter Replace.
Poor 1st speed run-
ning or excessive slip-
page in “D” or “2”Fluid pressure leakage from forward clutch due
to wear or breakage of O/D case seal ringReplace.
Overdrive clutch slipping Replace.
Unable to run or
excessive slippage in
“L” rangeFluid pressure leakage of forward clutch due to
wear or breakage of O/D case seal ringReplace.
Reverse brake disc slipping Replace.
Broken brake piston O-ring Replace.
Unable to run or
excessive slippage in
“R” rangeFluid pressure leakage to direct clutch due to
wear or breakage of center support seal ringReplace.
Worn direct clutch Replace.
Page 426 of 656

AUTOMATIC TRANSMISSION (4 A/T) 7B1-17
GEAR SHIFT
ABNORMAL NOISE
Scan Tool Data
Refer to Section 6-1.
Inspection of PCM and Its Circuit
Refer to Section 6-1.
Wire Harness and Connectors
Refer to Section 6-1.Condition Possible Cause Correction
Poor 1–2 shift, exces-
sive slippageFluid pressure leakage to overdrive clutch due
to wear or breakage of O/D case seal ringReplace.
Faulty second brake Replace.
Broken O-ring of second brake piston Replace.
Faulty second coast brake (in “2” range) Replace.
Poor 2–3 shift, exces-
sive slippageFluid pressure leakage to overdrive clutch due
to wear or breakage of O/D case seal ringReplace.
Worn direct clutch bushing Replace.
Direct clutch slipping Replace.
Foreign material caught in direct clutch piston
check ballReplace.
Poor start or surging
in “D” rangeFluid pressure leakage of forward clutch due to
wear or breakage of O/D case seal ringReplace.
Malfunction of forward clutch Replace.
Poor 3–4 shift, exces-
sive slippageFaulty overdrive brake Replace.
Faulty overdrive clutch Replace.
Poor start or juddering
in “R” rangeFluid pressure leakage of direct clutch due to
wear or breakage of oil center support seal ringReplace.
Worn direct clutch Replace.
Excessive shock on
1– 2 shiftFaulty one-way clutch Replace.
Non operate lock-up
systemFaulty torque converter Replace.
Condition Possible Cause Correction
Abnormal noise in “P”
or “N” rangeWorn oil pump Replace.
Page 428 of 656
AUTOMATIC TRANSMISSION (4 A/T) 7B1-19
5“4WD LOW” switch signal inspection :
With ignition switch ON, check voltage between
C51-1-26 terminal of PCM coupler and ground.
“4WD LOW” switch specification
Transfer gear position “4L” or “N” : 0 V
Transfer gear position “4H” or “2H” :
Battery voltage
Is the result as specified?Go to Step 6. Faulty “4WD LOW” switch
or its circuit.
If OK, substitute a known-
good PCM and recheck.
6 Is vehicle equipped with cruise control system? Go to Step 7. Substitute a know-good
PCM and recheck.
7 Cruise control signal inspection :
With ignition switch ON, check voltage between
E61-35 terminal of PCM coupler and ground.
Is it battery voltage?Substitute a known-good
PCM and recheck.Faulty cruise control mod-
ule or its circuit.
If OK, substitute a known-
good PCM and recheck. Step Action Yes No
Page 429 of 656

7B1-20 AUTOMATIC TRANSMISSION (4 A/T)
Table A-2 : No Gear Shift to O/D
SYSTEM DESCRIPTION
PCM does not shift to O/D gear under any of the following conditions.
•O/D off switch : ON
•4WD LOW switch : ON
•Cruise control module : O/D OFF command signal is output (if equipped).
•ECT : ECT < 30 °C (86 °F)
TROUBLESHOOTING
WARNING:
When performing a road test, select a place where there is no traffic or possibility of a traffic acci-
dent and very careful during testing to avoid occurrence of an accident.
Road test should be carried out with 2 person, a driver and tester, on a level road.
Step Action Yes No
1Was “AUTOMATIC TRANSMISSION DIAG-
NOSTIC FLOW TABLE” performed?Go to Step 2. Go to “AUTOMATIC
TRANSMISSION DIAG-
NOSTIC FLOW TABLE” in
this section.
2 ECT check :
1) Warm up engine to normal operating tem-
perature.
2) Check ECT using scan tool.
Is ECT more than 30 °C (86 °F)?Go to Step 3. Faulty ECT sensor, its cir-
cuit or engine cooling sys-
tem.
If OK, substitute a known-
good PCM and recheck.
3 Perform running test under the following condi-
tions and check voltage between C51-1-2 termi-
nal of PCM coupler and ground, C51-1-1
terminal of PCM coupler and ground.
•O/D off switch OFF (“O/D OFF” lamp OFF).
•Normal mode in “D” range.
•Transfer “2H” position.
•Cruise control is not operated (if equipped).
•Drive vehicle with 4th gear condition refer-
ring to “Gear shift diagram” in this section.
Is each voltage about 0 V?Faulty shift solenoid valve,
its circuit or transmission“GRN” wire or “GRN/
RED” wire shorted to
power circuit.
If OK, go to Step 4.
4 O/D off switch signal inspection :
With ignition switch ON, check voltage between
E61-33 terminal of PCM coupler and ground.
“O/D” cut switch specification
“O/D” cut switch OFF : Battery voltage
“O/D” cut switch ON : 0 V
Is the result as specified?Go to Step 5. Faulty O/D off switch or its
circuit.
If OK, substitute a known-
good PCM and recheck.