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.
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
WITHOUT BATTERY VOLTAGE
WITH BATTERY VOLTAGE
1. Oiler (with transmission fluid)
2. Solenoid valve
3. 12V battery
“A”: Side hole (Should be dry)
“B”: Exhausting fluid
AUTOMATIC TRANSMISSION (3 A / T) (VEHICLE WITH WU-TWC) 7B-37
“P” RANGE TEST
1) Stop vehicle on a slope, shift selector lever to P range and at the
same time apply parking brake.
2) After stopping engine, release parking brake lever gradually and
check that vehicle remains stationary.
SHIFT SOLENOID VALVE CHECK
Whenever shift solenoid valves are removed from transmission,
verify their valve function physically before they are reinstalled.
1) Apply oiler to solenoid valve and give compression by hands
and then check to be sure that transmission fluid from oiler does
not come out from side holes of solenoid valve when battery volt-
age is not conducted.
2) Holding the above condition, conduct battery voltage and then
make sure that fluid is exhausted with vigor.
NOTE:
If fluid does not come out with vigor in above step 2) inspec-
tion, do not reuse that solenoid valve.
7B-38 AUTOMATIC TRANSMISSION (3 A / T) (VEHICLE WITH WU-TWC)
TABLE B-1 GEAR SHIFT FAILURE IN “D” OR “2” RANGE
STEPACTIONYESNO
1Was “TABLE A-2 GEAR CHANGE FAILURE” performed?Go to Step 2.Go to “TABLE
A-2”.
2Is gear no shift at all?Go to Step 3.Go to Step 4.
3Perform vehicle speed sensor check refer to “OUTPUT
SPEED SENSOR CHECK” in this section.
Is check result satisfactory?Go to Step 5.Repair or
replace.
4Perform throttle position sensor check referring to DTC P0121
Flow Table in Section 6-1.
Is check result satisfactory?Go to Step 5.Repair or
replace.
5Perform “SHIFT SOLENOID VALVE CIRCUIT CHECK”
described later in this section.
Is check result satisfactory?Substitute a
known-good
PCM and
recheck.Replace shift
solenoid-A
(direct clutch
solenoid) valve
or shift
solenoid-B (2nd
brake solenoid)
valve.
TABLE B-2 GEAR IS SHIFTED TO 2ND GEAR IN “L” RANGE
VEHICLE DOES NOT MOVE BACKWARD IN “R” RANGE
NOTE:
Gear shift to 2nd may occur when selector lever is shifted from D or 2 to L, but this is normal.
STEP
ACTIONYESNO
1Was “TABLE A-2 GEAR CHANGE FAILURE” performed?Go to Step 2.Go to “TABLE
A-2”.
2Perform “SHIFT SOLENOID VALVE CIRCUIT CHECK”
described later in this section.
Is check result satisfactory?Substitute a
known-good
PCM and
recheck.Replace shift
solenoid-A
(direct clutch
solenoid) valve
or shift
solenoid-B (2nd
brake solenoid)
valve.