AUTOMATIC TRANSMISSION (3 A / T) (VEHICLE WITH WU-TWC) 7B-29
TROUBLESHOOTING
STEPACTIONYESNO
1Was “AUTOMATIC TRANSMISSION DIAGNOSTIC FLOW
TABLE” performed?Go to Step 2.Go to
“AUTOMATIC
TRANSMISSION
DIAGNOSTIC
FLOW TABLE”.
2Is DTC other than shift malfunction (DTC P0751 / P0756)
displayed?Go to applicable
DTC Flow Table.Go to Step 3.
3Perform Road Test to check if upshift and downshift take
place at specified vehicle speed, referring to “ROAD TEST”
in this section.
Do they take place properly?Intermittent
trouble. Check
electrical circuit
of system for
intermittent
referring to
“INTERMITTENT
AND POOR
CONNECTION”
in Section 0A.Go to Step 4.
4Perform Manual Shift Road Test referring to “MANUAL ROAD
TEST” in this section.
Is test result satisfactory?Go to Step 5.Go to “A/T
Basic Check”.
5Check Transmission Range Sensor and Its Circuit according
to Step 1 of DTC P0705 Flow Table.
Are they in good condition?Go to Step 6.“D” range
signal circuit
shorted to other
signal circuit or
TR sensor
malfunction.
6Check Output Shaft Speed Sensor and Its Circuit referring to
“OUTPUT SHAFT SPEED SENSOR CHECK” in this section.
Are they in good condition?Go to Step 7.Output shaft
speed sensor
circuit open or
short or output
shaft speed
sensor
malfunction.
7Check Shift Solenoid A and B for Operation referring to
“SHIFT SOLENOID VALVE CHECK” in this section.
Are they in good condition?Substitute a
known-good
PCM and
recheck.Replace shift
solenoid A or B.
7B-30 AUTOMATIC TRANSMISSION (3 A / T) (VEHICLE WITH WU-TWC)
TABLE A-1 NO STARTING OR SLIPPING IN ANY DRIVE RANGE
STEPACTIONYESNO
1Was “AUTOMATIC TRANSMISSION DIAGNOSTIC
FLOW TABLE” performed?Go to Step 2.Go to
“AUTOMATIC
TRANSMISSION
DIAGNOSTIC FLOW
TABLE”.
2Is engine rpm at stall test normal?Transmission
failure.Go to Step 3.
3Is engine rpm at stall test too low in any range?Poor engine power or
torque converter
defective.Go to Step 4.
4Is engine rpm at stall test too high only in “D” range?Go to Step 7.Go to Step 5.
5Is engine rpm at stall test too high only in “R” range?Go to Step 9.Go to Step 6.
6Is line pressure proper?Transmission failure.Oil pump defective,
Regulator valve
operation failure,
Throttle valve
operation failure or
Accelerator cable
and oil pressure
control cable
maladjusted.
7Does engine rpm at stall test become normal when
coupler of solenoid valve wire is disconnected?One-way clutch
operation failure.Go to Step 8.
8Is line pressure proper?Forward clutch worn.Oil leak in forward
clutch oil circuit or Oil
leak in “D” range oil
circuit.
9Does engine rpm at stall test become normal when
coupler of solenoid valve wire is disconnected?1st-Reverse brake
worn.Go to Step 10.
10Is line pressure proper?Direct clutch worn.Oil leak in direct
clutch oil circuit or Oil
leak in “R” range oil
circuit.
AUTOMATIC TRANSMISSION (3 A / T) (VEHICLE WITH WU-TWC) 7B-31
TABLE A-2 GEAR CHANGE FAILURE
STEPACTIONYESNO
1Was “AUTOMATIC TRANSMISSION DIAGNOSTIC
FLOW TABLE” performed?Go to Step 2.Go to “AUTOMATIC
TRANSMISSION
DIAGNOSTIC FLOW
TABLE”.
2Disconnect solenoid valve wire coupler and perform
manual road test.
Is upshift from 1st to 2nd possible?Go to Step 3.1-2 shift valve sticks
or Shift solenoid-B
(2nd brake solenoid)
valve sticks.
3Is upshift from 2nd to 3rd possible?Gear shift control
system defective.
Go to A / T Diagnostic
Flow Table B.2-3 shift valve sticks
or Shift solenoid-A
(Direct clutch
solenoid) valve
sticks.
TABLE A-3 EXCESSIVE SHOCK AT RANGE SELECTION OR GEAR CHANGE
STEPACTIONYESNO
1Was “AUTOMATIC TRANSMISSION DIAGNOSTIC
FLOW TABLE” performed?Go to Step 2.Go to “AUTOMATIC
TRANSMISSION
DIAGNOSTIC FLOW
TABLE”.
2Is line pressure proper?Go to Step 3.Regulator valve
defective, Throttle
valve defective or
Accelerator cable
maladjusted.
3Does excessive shock occur when selecting “D” range
from “N” range?Forward clutch
accumulator
operation failure,
Forward clutch worn
or Forward clutch oil
circuit check ball
operation failure. Go to Step 4.
4Does excessive shock occur when selecting “R” range
from “N” range?1st-Reverse brake
worn, 1st-Reverse
brake oil circuit check
ball operation failure.Go to Step 5.
5Does excessive shock occur at 1st to 2nd gear
change?2nd brake
accumulator
defective, 2nd brake
worn, 2nd brake oil
circuit check ball
operation failure.In case of excessive
shock at 2nd to 3rd
gear change, Direct
clutch worn or Direct
clutch oil circuit check
ball operation failure.
7B-32 AUTOMATIC TRANSMISSION (3 A / T) (VEHICLE WITH WU-TWC)
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 (70–80C / 158–176F) and its level is be-
tween FULL HOT and LOW HOT. (Refer to “Fluid level” in this sec-
tion.)
CAUTION:
Do not run engine at stall more than 5 seconds continuous-
ly, for oil temperature may rise excessively high.
1) Install tachometer.
2) Apply parking brake and block vehicle wheels.
3) Start engine with selector lever shifted to P range.
4) Depress brake pedal.
5) Shift selector lever to D range and depress accelerator pedal ful-
ly 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 at R range.
8) Stall speed should be within following specification.
Stall speed: 2,500 – 2,900 r / min
(For both G10 and G13 engine models)
9) Possible causes for out-of-specification stall speed are as fol-
lows. Check each part which is suspected to be the cause.
Stall speed measured
Possible causes
Lower than specificationEngine output insufficient
Torque converter defective
Higher than specification in
D rangeForward clutch slippage
One-way clutch defective
Higher than specification in
R rangeDirect clutch slippage
1st-reverse brake slippage
1. Front drive shaft (LH)
2. Oil pan
AUTOMATIC TRANSMISSION (3 A / T) (VEHICLE WITH WU-TWC) 7B-33
LINE PRESSURE TEST
This test is to check oil pressure system for operation by measuring
oil pressure in oil pressure line. Make sure to perform this test only
when transmission fluid is at normal operating temperature.
NOTE:
Make sure that transmission fluid level is between FULL HOT
and LOW HOT marks on oil level gauge at normal operating
temperature which corresponds to 70–80C (155–176F) of
fluid. (Refer to “Fluid level” in this section.)
Check that transmission is free from fluid leakage.
1) With engine at stop, remove plug and connect oil pressure
gauge to plug hole.
Special Tool
(A): 09925-37811-001
2) Install tachometer.
3) Apply parking brake and block vehicle wheels.
4) With selector lever shifted to P range, start engine.
5) Depress brake pedal fully.
6) Shift selector lever to D range and check oil pressure with engine
running at idling speed and at stall speed respectively.
7) Repeat the same check as in step 6) with selector lever shifted
to R range.
CAUTION:
Do not run engine at stall more than 5 seconds continu-
ously, for oil temperature may rise excessively high.
8) If line pressure is within respective specification in table below,
oil pressure system is in good condition.
[G10 Engine Model]
Engine speedLine pressureEngine s eedD rangeR range
Idling speed
200 – 390 kPa
2.0 – 3.9 kg / cm2
28.4 – 55.5 psi
540 – 780 kPa
5.4 – 7.8 kg / cm2
76.8 – 110.9 psi
Stall speed
390 – 590 kPa
3.9 – 5.9 kg / cm2
55.5 – 83.9 psi
880 – 1230 kPa
8.8 – 12.3 kg / cm2
125.1 – 174.9 psi
[G13 Engine Model]
Engine speedLine pressureEngine s eedD rangeR range
Idling speed
260 – 460 kPa
2.6 – 4.6 kg / cm2
37.0 – 65.4 psi
660 – 900 kPa
6.6 – 9.0 kg / cm2
93.9 – 128.0 psi
Stall speed
660 – 850 kPa
6.6 – 8.5 kg / cm2
93.9 – 120.9 psi
1330 kPa or more
13.3 kg / cm2 or more
189.0 psi or more
1. Drive shaft (LH)
2. Oil pan
7B-34 AUTOMATIC TRANSMISSION (3 A / T) (VEHICLE WITH WU-TWC)
9) Possible causes for out-of-specification line pressure are as
follows. Check each part which is suspected to be the cause.
Line pressure
Possible causes
Higher than specification
in D and R rangesRegulator valve defective
Throttle valve in valve body
defective
Accelerator cable and oil
pressure control cable
maladjusted
Lower than specification
in D and R rangesOil pump defective
Regulator valve defective
Throttle valve in valve body
defective
Accelerator cable and oil
pressure control cable
maladjusted
Lower than specification
only in D rangeForward clutch oil pressure
system oil leakage
D range oil pressure system
oil leakage
Lower than specification
only in R rangeDirect clutch oil pressure
system oil leakage
1st-reverse brake oil
pressure system oil leakage
R range oil pressure system
oil leakage
10) Reinstall plug and tighten it to specification.
Tightening Torque
(a): 7.5 N·m (0.75 kg-m, 5.5 lb-ft)
AUTOMATIC TRANSMISSION (3 A / T) (VEHICLE WITH WU-TWC) 7B-35
ROAD TEST
This test is to check if upshift and downshift take place at specified
speeds while actually driving vehicle on a level road.
WARNING:
Carry out the test in very little traffic area to prevent an ac-
cident.
The test requires 2 persons, a driver and a tester.
1) Warm up engine.
2) With engine running at idle, shift selector lever to D range.
3) i) Accelerate vehicle speed by depressing accelerator pedal
very little (within 4 deg. of throttle valve opening).
ii) Check if upshift takes place from 1st to 2nd at about 18 km / h
(11 mile / h) and from 2nd to 3rd at about 30 km / h (19 mile / h).
iii)
[For G10 Engine Model]
Stop vehicle once. Then start it again and while accelerating
by depressing accelerator pedal fully, check if upshift takes
place from 1st to 2nd at 52 km / h (33 mile / h) and from 2nd to
3rd at 97 km / h (61 mile / h).
[For G13 Engine Model]
Stop vehicle once. Then start it again and while accelerating
by depressing accelerator pedal fully, check if upshift takes
place from 1st to 2nd at 58 km / h (36 mile / h) and from 2nd to
3rd at 110 km / h (69 mile / h).
iv) Stop vehicle again.
v) Start vehicle and keep it running at 25 km / h (15 mile / h) and
then release accelerator pedal completely. 1 or 2 seconds lat-
er, depress accelerator pedal fully and check if downshift
from 2nd to 1st takes place.
vi) Keep vehicle running at 75 km / h (47 miles / h) and in the
same way as in step v), check if downshift from 3rd to 2nd
takes place.
vii) If upshift or downshift fails to take place at each specified
speed in the road test, possible causes for such failure are as
follows. Check each part which is suspected to be the cause.
Condition
Possible causes
No upshift from 1st
to 2nd1 – 2 shift valve defective
2nd brake solenoid valve defective
PCM defective, or disconnection or
poor connection in electric circuit
No upshift from
2nd to 3rd2-3 shift valve defective
Direct clutch solenoid valve defective
PCM defective, or disconnection or
poor connection in electric circuit
No downshift from
2nd to 1st or 3rd to
2ndThrottle position sensor defective
PCM defective, or disconnection or
poor connection in electric circuit
1. Solenoid valve wire coupler (Disconnected)
2. Transmission
7B-36 AUTOMATIC TRANSMISSION (3 A / T) (VEHICLE WITH WU-TWC)
MANUAL ROAD TEST
This test checks the gears being used in L, 2 or D range when driven
with unoperated gear shift control system.
Test drive vehicle on a level road.
1) With selector lever in P range, start engine and warm it up.
2) After warming up engine, disconnect coupler of solenoid valve
wire as shown in left figure.
3) With selector lever in L range, start vehicle and accelerate to
30 km / h (19 mile / h). Check in this state that 1st gear is being
used.
4) At 30 km / h (19 mile / h), shift selector lever to 2 range and accel-
erate to 60 km / h (37 mile / h).
Check in this state that 2nd gear is being used.
5) At 60 km / h (37 mile / h), shift selector lever to D range and check
that 3rd gear is used when speed is higher than 60 km / h
(37 mile / h).
6) After above checks, stop vehicle then engine, and connect sole-
noid valve wire coupler.
ENGINE BRAKE TEST
WARNING:
Before test, make sure that there is no vehicle behind so as
to prevent rear-end collision.
1) While driving vehicle in 3rd gear of D range, shift selector lever
down to 2 range and check if engine brake operates.
2) In the same way as in step 1), check engine brake for operation
when selector lever is shifted down to L range.
3) If engine brake fails to operate in above tests, possible cause for
such failure are as follows.
Check each part which is suspected to be the cause.
Condition
Possible causes
Fails to operate when
shifted down to 2 rangeSecond brake defective
Fails to operate when
shifted down to L range1st-reverse brake defective