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.
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.
7B1-38 AUTOMATIC TRANSMISSION (4 A/T)
Stall Test
This test is to check overall performance of automatic transmission and engine by measuring stall speed at “D”
and “R” ranges. Be sure to perform this test only when transmission fluid is at normal operating temperature and
its level is between FULL and LOW marks.
1) Apply parking brake and block wheels.
2) Install tachometer.
3) Start engine with select lever shifted to “P”.
4) Depress brake pedal fully.
5) Shift select lever to “D” and depress accelerator pedal fully while watching tachometer. Read engine rpm
quickly when it has become constant (stall speed).
6) Release accelerator pedal immediately after stall speed is checked.
7) In the same way, check stall speed in “R” range.
8) Stall speed should be within the following specification.
Stall speed :
2,460 – 2,760 r/min.
TROUBLESHOOTING
CAUTION:
Do not run engine at stall more than 5 seconds continuously, for fluid temperature may rise exces-
sively high.
After performing stall test, be sure to leave engine running at idle for longer than 30 seconds before
another stall test.
Condition Possible cause
Lower than standard level•Faulty engine output
•Defective torque converter
Higher than standard level in “D” range•Slippery O/D clutch
•Slippery forward clutch
•Malfunctioning O/D one-way clutch
•Malfunctioning one-way clutch No. 2
•Low line pressure
Higher than standard level in “R” range•Slippery direct clutch
•Slippery reverse brake
•Low fluid pressure
•Slippery O/D clutch
•Defective O/D one-way clutch
AUTOMATIC TRANSMISSION (4 A/T) 7B1-39
Line Pressure Test
Purpose of this test is to check operating conditions of each part
by measuring fluid pressure in fluid pressure line. Line pressure
test requires following conditions.
•Automatic fluid is at normal operating temperature (70 to 80
°
C/158 – 176 °F).
•Fluid is filled to proper level (between FULL HOT and LOW
HOT on dipstick).
1) Apply parking brake securely and place checks against
wheels.
2) Attach oil pressure gauge to fluid pressure check hole (1) in
transmission case.
Special tool
(A) : 09925-37811-001
3) Depress foot brake fully, run engine at idle and stall.
4) Check fluid pressure in “D” or “R” range within the following
specification.
Line pressure :
5) If check result is OK, disconnect special tool, then tighten
transmission case plug to specified torque.
Tightening torque
Transmission case plug : 17 N·m (1.7 kg-m, 12.0 lb-ft) CAUTION:
After attaching oil pressure gauge, check that not fluid
leakage exists.
CAUTION:
Do not continue running engine at stall speed longer
than 5 seconds.
“D” range“R” range
Idle speed
4.1 – 4.6 kg/cm
2
58 – 65 psi5.4 – 6.0 kg/cm
2
77 – 85 psi
Stall speed
12.0 – 13.5 kg/cm
2
171 – 192 psi14.6 – 17.1 kg/cm
2
208 – 243 psi
7B1-40 AUTOMATIC TRANSMISSION (4 A/T)
TROUBLESHOOTING
Road Test
This test is to check if upshift and downshift take place at specified speed while actually driving vehicle on a
level road.
1) Warm up engine.
2) With engine running at idle, shift select lever “D”.
3) Accelerate vehicle speed by depressing accelerator pedal gradually.
4) While driving in “D” range, check if gear shift occurs properly as shown in “GEAR SHIFT DIAGRAM” in this
section.
TROUBLESHOOTING
Condition Possible cause
Line pressure higher than standard level in each
range•Malfunctioning regulator valve
•Malfunctioning throttle valve
•Maladjusted A/T throttle cable
Line pressure lower than standard level in each
range•Defective O/D clutch
•Defective oil pump
•Malfunctioning throttle valve
•Malfunctioning regulator value
•Maladjusted A/T throttle cable
Line pressure lower than standard level only in
“D” range•Fluid leakage from forward clutch
•Defective O/D clutch
•Leakage from “D” range fluid pressure circuit
Line pressure lower than standard level only in
“R” range•Fluid leakage from direct clutch
•Defective O/D clutch
•Fluid leakage from reverse brake
•Fluid leakage from “R” range fluid circuit
WARNING:
Carry out test in very little traffic area to prevent an accident.
Test requires 2 persons, a driver and a tester.
Condition Possible cause
When 1 → 2 upshift fails to occur 1–2 shift valve stuck
When 2 → 3 upshift fails to occur 2–3 shift valve stuck
When 3 → O/D upshift fails to occur 3–4 shift valve stuck
When gear shift point is incorrect•Maladjusted throttle cable
•Defective shift solenoid valve -A or -B
•1–2, 2–3 or 3–4 shift valve not operating properly
AUTOMATIC TRANSMISSION (4 A/T) 7B1-41
Manual Road Test
This test check the gear being used in “L”, “2” or “D” range when
driven with unoperated gear shift control system. Test drive vehi-
cle on a level road.
1) Disconnect shift solenoid coupler (1) valves on transmission.
2) With select lever in “P”, start engine and warm it up.
3) With select lever in “L” range, start vehicle and accelerate to
20 km/h (12.5 mile/h). Check in this state that 1st gear is
being used.
4) At 20 km/h (12.5 mile/h), shift select lever to “2” range and
accelerate to 40 km/h (25 mile/h). Check in this state that 3rd
gear is being used.
5) At 40 km/h (25 mile/h), shift select lever to “D” range and
check that O/D gear is used when speed is higher than 40
km/h (25 mile/h).
6) After above checks, stop vehicle then engine, and connect
shift solenoids coupler (1) with ignition switch OFF.
7) Clear DTC with scan tool.
Time Lag Test
This test is to check conditions of clutch, reverse brake and fluid pressure. “Time lag” means time elapsed since
select lever is shifted with engine idling till shock is felt.
1) With chocks placed before and behind front and rear wheels respectively, depress brake pedal.
2) Start engine.
3) With stop watch ready, shift select lever from “N” to “D” range and measure time from that moment till shock
is felt.
4) Similarly measure time lag by shifting select lever from “N“ to “R” range.
Specification for time lag :NOTE:
Before this test, check diagnostic trouble code (DTC).
WARNING:
To avoid the danger of being burned, do not touch the hot
exhaust system when disconnecting shift solenoid cou-
pler (1).
WARNING:
To avoid the danger of being burned, do not touch the hot
exhaust system when connecting shift solenoid coupler
(1).
“N” →
→→ → “D”Less than 1.2 sec.
“N” →
→→ → “R”Less than 1.5 sec.
AUTOMATIC TRANSMISSION (4 A/T) 7B1-43
On-Vehicle Service
Maintenance Service
Fluid level
LEVEL CHECK AT NORMAL OPERATING TEMPERATURE
1) Stop vehicle and place it level.
2) Apply parking brake and place chocks against wheels.
3) With selector at P position, start engine.
4) Warm up engine till fluid temperature reaches normal oper-
ating temperature (70 – 80 °C (158 – 176 °F)). As a guide to
check fluid temperature, warm up engine till engine coolant
temperature meter indicated around 1 unit above “C” point.
5) Keep engine idling and shift selector slowly to “L” and back
to “P” position.
6) With engine idling, pull out dipstick, wipe it off with a clean
cloth and put it back into place.
7) Pull out dipstick again and check fluid level indicated on it.
Fluid level should be between FULL HOT and LOW HOT. if it
is below LOW HOT, add an equivalent of DEXRON
®-III up to
FULL HOT.
Fluid specification :
An equivalent of DEXRON
®-III
[A] : Shift the select lever with its button pushed in.
[B] : Shift the select lever without pushing its button.
NOTE:
DO NOT RACE ENGINE while checking fluid level, even
after the engine start.
DO NOT OVERFILL. Overfilling can causes foaming
and loss of fluid through breather. Then slippage and
transmission failure can result.
Bringing the level from LOW HOT to FULL HOT
requires 0.3 liters (0.64/0.53 US/lmp.pt).
If vehicle was driven under high load such as pulling a
trailer, fluid level should be checked about half an hour
after it is stopped.
7B1-44 AUTOMATIC TRANSMISSION (4 A/T)
LEVEL CHECK AT ROOM TEMPERATURE
The fluid level check at room temperature (20 – 30 °C (68 – 86
°F)) performed after repair or fluid change before test driving is
just preparation for level check of normal operating temperature.
The checking procedure itself is the same as that described previ-
ously. If the fluid level is between FULL COLD and LOW COLD,
proceed to test drive. And when the fluid temperature has
reached the normal operating temperature, check fluid level again
and adjust it as necessary.
Fluid change
1) Lift up vehicle.
2) With engine is cool, remove drain plug (1) from oil pan and
drain A/T fluid.
3) Install drain plug (1).
Tightening torque
A/T fluid drain plug (a) :
23 N·m (2.3 kg-m, 17.0 lb-ft)
4) Lower vehicle and fill proper amount of an equivalent of
DEXRON
®-III.
5) Check fluid level referring to “LEVEL CHECK NORMAL
OPERATING TEMPERATURE” of “FLUID LEVEL” in this
section.
Fluid specification :
An equivalent of DEXRON
®-III
Fluid capacity
When draining from drain plug hole:
2.5 liters (5.28/4.40 US/lmp.pt.)
When overhauling:
6.8 liters (14.37/11.97 US/lmp.pt.)