AT2–14

A340H AUTOMATIC TRANSMISSION – TROUBLESHOOTING

TROUBLESHOOTING
BASIC TROUBLESHOOTING
Before troubleshooting an electronically controlled transmission first determine whether the problem
is electrical or mechanical. To do this, just refer to the basic troubleshooting flow–chart provided below.
If the cause is already known, using the basic troubleshooting chart below along with the general trou-
bleshooting chart on the following pages should speed the procedure.

Read Diagnostic Trouble Code

(See page AT2–18)

Repair or Replace

Preliminary Check
(See page AT2–24)

Manual Shifting Test

(See page AT2–28)

Electronic Control System Check Stall Test, Time Lag Test and
Hydraulic Test
NG

Repair or Replace Repair Transmission

 AT2–15
A340H AUTOMATIC TRANSMISSION – TROUBLESHOOTING

NOTICE: Refer to A340E, A340F, A340H Automatic Transmission Repair Manual (Pub. No. RM391 U)
when
mark appears in the column for page numbers.

Problem Possible Cause Remedy Page

Fluid discolored or smells burnt Fluid contaminated Replace fluid AT2–24

Torque converter clutch faulty Replace torque converter clutch AT2–72
Transmission faulty Disassemble and inspect

transmission

Vehicle does not move in Manual linkage out of adjustment Adjust linkage AT2–26
any forward position of Valve body or primary regulator faulty Inspect valve body

reverse Parking lock pawl faulty Inspect parking lock pawl AT2–70
Torque converter clutch faulty Replace torque converter clutch AT2–72
Converter drive plate broken Replace drive plate AT2–75
Oil pump intake screen blocked Clean screen

Transmission faulty Disassemble and inspect

transmission

Shift lever position incorrect Manual linkage out of adjustment Adjust linkage AT2–26
Manual valve and lever faulty Inspect valve body

Transmission faulty Disassemble and inspect

transmission

Harsh engagement into any Throttle cable out of adjustment Adjust throttle cable AT2–26
drive position Valve body or primary regulator faulty . Inspect valve body

Accumulator piston faulty Inspect accumulator pistons

Transmission faulty Disassemble and inspect

transmission

Delayed 1–2, 2–3 or 3–O/D Electronic control faulty Inspect electronic control AT2–30
up–shift, or down–shift, from Valve body faulty Inspect valve body

O/D–3 or 3–2 and shifts back to Solenoid valve faulty Inspect solenoid valve AT2–39
O/D or 3

Slips on 1–2, 2–3 or 3–O/D Manual linkage out of adjustment Adjust linkage AT2–26
up–shift, or slips or shudders on Throttle cable out of adjustment Adjust throttle cable AT2–26
acceleration Valve body faulty Inspect valve body

Solenoid valve faulty Inspect solenoid valve AT2–39
Transmission faulty Disassemble and inspect

transmission

Drag, binding or tie–up on Manual linkage out of adjustment Adjust linkage AT2–26
1–2, 2–3 or 3–0/D up–shift Valve body faulty Inspect valve body

Transmission faulty Disassemble and inspect

transmission
AT2–16
A340H AUTOMATIC TRANSMISSION – TROUBLESHOOTING

NOTICE: Refer to A340E, A340F, A340H Automatic Transmission Repair Manual (Pub. No. RM391 U)
when
mark appears in the column for page numbers.

Problem Possible cause Remedy Page

No lock–up in 2nd, Electronic control faulty Inspect electronic control AT2–30

3rd or O/D Valve body faulty Inspect valve body

Solenoid valve faulty Inspect solenoid valve

Transmission faulty Disassemble and inspect

transmission

Harsh down–shift Throttle cable out of adjustment Adjust throttle cable AT2–26
Throttle cable and cam faulty Inspect throttle cable and cam AT2–67
Accumulator pistons faulty Inspect accumulator pistons

Valve body faulty Inspect valve body

Transmission faulty Disassemble and inspect

transmission

No down–shift when Valve body faulty Inspect valve body

coasting Solenoid valve faulty Inspect solenoid valve

Electronic control faulty Inspect electronic control AT2–30

Down–shift occurs too Throttle cable faulty Inspect throttle cable AT2–26
quickly or too late while Valve body faulty Inspect valve body

coasting Transmission faulty Disassemble and inspect

Solenoid valve faulty transmission
Electronic control faulty Inspect solenoid valve *


Inspect electronic control AT2–30

No O/D–3, 3–2 or 2–1 Solenoid valve faulty Inspect solenoid valve

kick–down Electronic control faulty Inspect electronic control AT2–30
Valve body faulty Inspect valve body

No engine braking in Solenoid valve faulty Inspect solenoid valve *

2 or L position Electronic control faulty Inspect electronic control
AT2–30
Valve body faulty Inspect valve body


Transmission faulty Disassemble and inspect


transmission

Vehicle does not hold in P Manual linkage out of adjustment Adjust linkage AT2–26
Parking lock pawl cam and spring faulty Inspect cam and spring AT2–70

No H2–H4, H4–L4, Transfer linkage out of adjustment Adjust linkage AT2–26

L4–H4 or H4–H2 Electronic control faulty Inspect electronic control AT2–30
change gear position of Transfer valve body faulty Inspect valve body

transfer Transfer faulty Disassemble and inspect

transfer
 AT2–17
A340H AUTOMATIC TRANSMISSION – TROUBLESHOOTING

DIAGNOSTIC SYSTEM
DESCRIPTION
1. A self–diagnosis function is built into the electrical control
system. Warning is indicated by the 0/D OFF
indicator light.
HINT: Warning and DTC can be read only when the
O/D main switch is ON. If OFF, the O/D OFF light is lit
continuously and will not blink.
(a) If a malfunction occurs within the vehicle speed sen–
sors (No. 1 or 2) or solenoids (No. 1, 2 or 4), the O/D
OFF light will blink to warn the driver.
However, there will be no warning of a malfunction
with lock–up solenoid.
(b) The DTC can be read by the number of blinks of the
O/D OFF indicator light when terminals TE1 and E1
are connected with SST.
(See page AT2–18)
(c) The throttle position sensor or brake signal are not
indicated, but inspection can be made by checking
the voltage at terminal TT of the DLC1.
(d) The signals to each gear can be checked by mea-
suring the voltage at terminal TT of the DLC1 while
driving.
2. The DTC is retained in memory by the ECM and due to
back – up voltage, is not canceled out when the
engine is turned oft. Consequently, after repair, it is
necessary to turn the ignition switch off and cancel
out the DTC.
(See page AT2–20)
HINT:
• Low battery voltage will cause faulty operation
of the diagnosis system. Therefore, always check
the battery first.
• Use a voltmeter and ohmmeter that have an imped-
ance of at least 10 k
/V.

CHECK ”O/D OFF INDICATOR LIGHT

1. Turn the ignition switch ON.
2. The ’O/D OFF” light will come on when the O/D is switched
OFF.
3. When the O/D main switch is set to ON, the ”O/D
OFF” light should go out.
If the ”O/D OFF” light flashes when the O/D main switch
is set to ON, the electronic control system is faulty.
AT2–18
A340H AUTOMATIC TRANSMISSION – TROUBLESHOOTING

READ DIAGNOSTIC TROUBLE CODE

1. TURN IGNITION SWITCH AND O/D MAIN SWITCH
TO ON
Do not start the engine.
HINT: Warning and DTC can be read only when the
O/D main switch is ON. If OFF, the O/D OFF light will light
continuously and will not blink.

2. CONNECT TE1 TERMINALS OF DLC1

Using SST, connect terminals TE1 and El.
SST 09843–18020

3. READ DIAGNOSTIC TROUBLE CODE

Read the DTC is indicated by the number of times the
O/D OFF tight flashes.

Diagnostic Trouble Code Indication

• If the system is operating normally, the light will
flash 2 times per second.

• In the event of a malfunction, the light will flash 1

time per second. The number of blinks will equal the
first number and, after 1.5 seconds pause, the sec-
ond number of the 2 digit diagnostic trouble code.
If there are 2 or more codes, there will be a 2.5 sec-
onds pause between each.
HINT: In the event of several trouble codes occurring si–
multaneously, indication will begin from the smaller val–
ue and continue to the larger.
4. REMOVE SST
 AT2–19
A340H AUTOMATIC TRANSMISSION – TROUBLESHOOTING

DIAGNOSTIC TROUBLE CODE

Code No. Light Pattern Diagnosis System

Normal

Defective No. 1 vehicle speed sensor (in combination meter) –

severed wire harness or short circuit

Defective No. 2 vehicle speed sensor (in ATM)–

severed wire harness or short circuit
Severed No. 1 solenoid or short circuit –
severed wire harness or short circuit
Severed No.2 solenoid or short circuit –
severed wire harness or short circuit
Severed lock–up solenoid or short circuit –
severed wire harness or short circuit
Severed No.4 solenoid or short circuit –
severed wire harness or short circuit

HINT: If codes 62, 63, 64 or 65 appear, there is an elec-

trical malfunction in the solenoid.
Causes due to mechanical failure, such as a stuck
valve, will not appear.
AT2–20
A340H AUTOMATIC TRANSMISSION – TROUBLESHOOTING

CANCEL OUT DIAGNOSTIC TROUBLE

CODE
1. After repair of the trouble area, the DTC retained in
memory by the ECM must be canceled by removing the
EFI fuse (15A) for 10 seconds or more, depending
on ambient temperature (the lower the temperature, the
longer the fuse must be left out) with the ignition switch
OFF.
HINT:
• Cancellation can be also done by removing the
negative (–) terminal cable of the battery, but in this
case other memory systems will be also canceled
out.
• The DTC can be also canceled out by disconnect-
ing the ECM connector.
• If the DTC is not canceled out, it will be retained by
the ECM and appear along with a new code in event
of future trouble.
2. After cancellation, perform a road test to confirm that a
”normal code” is now read on the O/D OFF indicator light.
 AT2–21
A340H AUTOMATIC TRANSMISSION – TROUBLESHOOTING

TROUBLESHOOTING FLOW–CHART
HINT:
• If DTC Nos. 42, 61, 62, 63 or 65 are output, the overdrive OFF indicator light will begin to blink imme-
diately to warn the driver. However, an impact or shock may cause the blinking to stop; but the code
will still be retained in the ECM memory unit canceled out.
• There is no warning for DTC No. 64.
• In the event of a simultaneous malfunction of both No.1 and No.2 vehicle speed sensors, no
DTC will appear and the fail–safe system will not function. However, when driving in the D
position, the transmission will not up–shift from first gear, regardless of the vehicle speed.

Diagnostic trouble code 42 (No. 1 vehicle speed sensor circuitry)

Check continuity between ECM connector SP1 NG
terminal and body ground.
(See page AT2–38)

Substitute another ECM.

Check No.1 vehicle speed sensor. Repair or replace No.1 vehicle speed
(See page BE–48) sensor.

Check wiring between ECM and combination

meter.

Diagnostic trouble code 61 (No.2 vehicle speed sensor circuitry)

Check continuity between ECM connector SP2 NG
terminal and body ground.
(See page AT2–38)

Substitute another ECM.

Check No.2 vehicle speed sensor. Repair or replace No.2 vehicle speed
(See page AT2–40) sensor.

Check wiring between ECM and No.2 vehicle speed

sensor.
AT2–22
A340H AUTOMATIC TRANSMISSION – TROUBLESHOOTING

Diagnostic trouble code 62 (No. 1 solenoid valve circuitry)

Check resistance of No. 1 solenoid valve at ECM
connector. (See page AT2–39)

Substitute another ECM.

Remove the oil pan and check resistance of No. 1 Replace No. 1 solenoid valve.
solenoid valve connector and body ground.
Resistance: 11 – 15 Ω

Check wiring between No. 1 solenoid valve and

ECM.

Diagnostic trouble code 63 (No. 2 solenoid valve circuitry)

NG
Check resistance of No. 2 solenoid valve at ECM
connector. (See page AT2–39)

Substitute another ECM.

Remove the oil pan and check resistance of No. 2 Replace No. 2 solenoid valve.
solenoid valve connector and body ground.
Resistance: 11 – 15

Check wiring between No. 2 solenoid valve and ECM.

Diagnostic trouble code 64 (Lock–up solenoid valve circuitry)

NG
Check resistance of Lock–up solenoid valve at
ECM connector. (See page AT2–39)

Substitute another ECM.

Remove the oil pan and check resistance of lockup Replace lock–up solenoid valve.
solenoid valve connector and body ground.
Resistance: 11 – 115

Check wiring between lock–up solenoid valve and

ECM.
 AT2–23
A340H AUTOMATIC TRANSMISSION – TROUBLESHOOTING

Diagnostic trouble code 65 INo.4 solenoid valve circuitry)

Check resistance of No.4 solenoid valve at

ECM connector.
(See page AT2–39)

Substitute another ECM.

Remove the transfer oil pan and check re- Replace No.4 solenoid valve.
sistance of No.4 solenoid valve connector
and body ground.
Resistance: 11 – 15

Check wiring between No.4 solenoid valve and

ECM.
AT2–24
A340H AUTOMATIC TRANSMISSION – TROUBLESHOOTING

PRELIMINARY CHECK
1. CHECK FLUID LEVEL
Transmission and transfer case:
HINT:
• The vehicle must have been driven so that the en-
gine and transmission are at normal operating tem-
perature.
Fluid temperature: 70–80°C (158–176°F)
• Only use the COOL range on the dipstick as a
rough reference when the fluid is replaced or the en-
gine does not run.
(a) Park the vehicle on a level surface, set the parking
brake.
(b) With the engine idling, shift the shift lever into all
positions from P to L position and return to P posi-
tion.
(c) Pull out the transmission dipstick and wipe it clean.
(d) Push it back fully into the pipe.
(e) Pull it out and check that the fluid level is in the HOT
range.
If the level is at the low side, add fluid.
Fluid type:
ATF DEXRON II
NOTICE: Do not overfill.
Transfer chain case:
Remove the filler plug and feel inside the hole with
your finger. Check that the oil comes to within 10 mm
(0.39 in.) of the bottom edge of the hole.
If the level is low, add fluid until it begins to run out of the filler
hole.
Fluid type:
ATF DEXRON II
2. CHECK FLUID CONDITION
If the fluid smells burnt or is black, replace it as
following procedures.
Transmission and transfer case:
(a) Remove the drain plugs and drain the fluid.
(b) Reinstall the drain plugs securely.
 AT2–25
A340H AUTOMATIC TRANSMISSION – TROUBLESHOOTING

(c) With the engine OFF, add new fluid through the oil
filler pipe.
Fluid type:
ATF DEXRON II
Capacity:
Transmission Transfer
liter (US qts, Imp. qts) liter (US qts, Imp. qts)

Drain and refill

Dry fill

(d) Start the engine and shift the shift lever into all posi-
tions from P to L position and then shift into P posi-
tion.
(e) With the engine idling, check the fluid level. Add fluid
up to the COOL level on the dipstick.

(f) Check the fluid level with the normal operating tem-
perature 70–80°C (158 – 176°F) and add as neces-
sary.
NOTICE: Do not overfill.

Transfer chain case:

(a) Remove the transfer under cover.
(b) Remove the drain plug with a hexagon wrench and
drain the fluid.
(c) Reinstall the drain plug securely with a hexagon
wrench.
(d) With the engine OFF, add new fluid through the filler
hole.
Capacity:
Dry fill – 1.1 liters (1.2 US qts. 1.0 Imp. qts)
Drain and refill – 0.8 liters (0.8 US qts, 0.7 Imp. qts)
(e) Check the fluid level.
(f) Install the transfer under cover.
AT2–26
A340H AUTOMATIC TRANSMISSION – TROUBLESHOOTING

3. INSPECT THROTTLE CABLE

(a) Depress the accelerator pedal all the way and check
that the throttle valve opens fully.
HINT: If the valve does not open fully, adjust the accelera–
tor cable.
(b) Fully depress the accelerator pedal.
(c) Measure the distance between the end of the boot
and stopper on the cable.
Standard distance:
0 – 1 mm (0 – 0.04 in.)
If the distance is not standard, adjust the cable by the a
justing nuts.

4. INSPECT TRANSMISSION SHIFT LEVER POSITION

When shifting the shift lover from the N position to other
positions, check that the lever can be shifted smoothly
and accurately to each position and that the position indi-
cator correctly indicates the position.
If the indicator is not aligned with the correct position,
carry out the following adjustment procedures.
(a) Loosen the nuts on the transmission control rod.
(b) Push the control shaft lever fully rearward.
(c) Return the control shaft lever 2 notches to N posi-
tion.
(d) Set the shift lever to N position.
(e) While holding the shift lever lightly toward the R
position side, tighten the nuts.
(f) Start the engine and make sure that the vehicle
moves forward when shifting the lever from the N to
D position and reverse when shifting it to the R posi-
tion.

5. INSPECT PARK/NEUTRAL POSITION SWITCH

Check that the engine can be started with the shift lever
only in the N or P position, but not in other positions.
If not as stated above, carry out the following adjustment
procedures.
(a) Loosen the park/neutral position switch bolt and set
the shift lever to the N position.
(b) Align the groove and neutral basic line.
 AT2–27
A340H AUTOMATIC TRANSMISSION – TROUBLESHOOTING

(c) Hold in position and tighten the bolt.

Torque: 13 N–m (130 kgf–cm, 9 ft–Ibf)

6. INSPECT TRANSFER SHIFT LEVER POSITION

When shifting the shift lever from H2 position to H4
and L4 positions, check that the lever can be shifted
smoothly and accurately to each position and that the
position indicator correctly indicates the position.
If the indicator is not aligned with the correct position,
carry out the following adjustment procedures.
(a) Loosen the nut on the cross shaft.
(b) Push the control shaft lever fully forward.
(c) Return the control shaft lever 1 notch to H4 position.
(d) Set the shift lever 4 position.
(e) While holding the shift lever lightly toward the L4
position side, tighten the nut.

7. INSPECT TRANSFER POSITION SWITCH

If necessary, carry out the following adjustment proce-
dures.
(a) Loosen the transfer position switch bolt and set the
transfer shift lever to the H4 position.
(b) Align the groove and H4 basic line.
(c) Hold in position and tighten the bolt.
Torque: 13 N–m (130 kgficm, 9 ft–lbf)

8. INSPECT IDLE SPEED

Connect a tachometer test probe to the data link connec-
tor 1 terminal (E), inspect the idle speed.
Idle speed:
800 ± 50 rpm (in N position and air conditioner OFF)
AT2–28
A340H AUTOMATIC TRANSMISSION – TROUBLESHOOTING

MANUAL SHIFTING TEST

HINT: With this test, it can be determined whether the
trouble lies within the electrical circuit or is a mechanical
problem in the transmission.
1. DISCONNECT SOLENOID WIRE
2. INSPECT MANUAL DRIVING OPERATION
Check that the shift and gear positions correspond with
the table below.

Transmission Transfer (Reference)

Shift position

Gear position

HINT: If the L, 2 and D position gear positions are difficult

to distinguish, perform the following road test.
• While driving, shift through the L, 2 and D positions.
Check that the gear change corresponds to the shift
position.
If any abnormality is found in the above test, the problem
lies in transmission itself.
3. CONNECT SOLENOID WIRE
4. CANCEL OUT DIAGNOSTIC TROUBLE CODE
(See page AT2–20)
 AT2–29
A340H AUTOMATIC TRANSMISSION – TROUBLESHOOTING

REFERENCE: Possible gear positions in accordance with solenoid operating conditions.

NO.1 SOLENOID NO.2 SOLENOID BOTH SOLENOIDS
NORMAL MALFUNCTIONING MALFUNCTIONING
MALFUNCTIONING
Solenoid Valve Gear Solenoid Valve Solenoid Valve Solenoid Valve Gear
Gear Gear
Position No. 1 No.2 Position No. 1 No.2 Position No. 1 No.2 Position No. 1 No.2 Position

D position

2 position

L position

X: Malfunctions
AT2–30
A340H AUTOMATIC TRANSMISSION – TROUBLESHOOTING

ELECTRONIC CONTROL SYSTEM

PRECAUTION
Do not open the cover or the case of the ECM and
various ECU unless absolutely necessary. (If the IC
terminals are touched, the IC may be destroyed by static
electricity.)
ELECTRONIC CONTROL CIRCUIT
 AT2–31
A340H AUTOMATIC TRANSMISSION – TROUBLESHOOTING

ELECTRONIC CONTROL COMPONENTS

AT2–32
A340H AUTOMATIC TRANSMISSION – TROUBLESHOOTING

TROUBLESHOOTING FLOW–CHART

Trouble No. 1 No Shifting

Warm up erigine
Coolant temp.: 80°C (176°F)
ATF temp.: 50 – 80°C (122 – 176°F)

Connect a voltmeter to DLC1 terminal TT and E1.

Does TT terminal voltage vary with changes in throttle
opening?

Yes
Is voltage between ECM terminals STP and E1 as Brake signal
follows? faulty
0 V: Brake pedal released
9 –14 V: Brake pedal depressed

Yes

• Throttle position signal faulty

• TT terminal wire open or short

Disconnect solenoid wire connector and road test. Transmission faulty

Does the transmission operate in the respective
gear when in the following positions while driving.?
D position .... O/D
2 position .... 3rd gear
L position .... 1st gear

Yes
Connect solenoid wire connector and road test. • Transmission faulty
Does DLC1 TT terminal voltage rise from
0 V to 7 V in sequence? • Solenoid faulty

Proceed to trouble 3 (AT2–34)

Are there 9 –14 V between ECM

terminals 2 – E1 when in the D position?

Yes
Are there 9 –14 V between ECM terminals L – E1
when in the D position?

Yes

• Park/neutral position switch circuit faulty

• Park/neutral position switch faulty

Try another ECM

 AT2–33
A340H AUTOMATIC TRANSMISSION – TROUBLESHOOTING

Trouble No.2 Shift point too high or too low

Warm up engine
Coolant temp.: 80°C (176°F)
ATF temp.: 50 – 80°C (122 –176°F)

Connect a voltmeter to DLC 1 terminal TT and El.

Does TT terminal voltage vary with changes in
throttle opening?

Yes

Brake signal faulty

Is voltage between ECM terminals STP and E1 as
follows?
0 V: Brake pedal released
9 –14 V: Brake pedal depressed
Yes

• Throttle position signal faulty

• TT terminal wire open or short

• Faulty ECM
Check voltage between ECM terminals P and E1. • Faulty transmission
Power pattern: 12 V
Normal pattaern: 1 V

faulty pattern select switch system

AT2–34
A340H AUTOMATIC TRANSMISSION – TROUBLESHOOTING

Trouble No.3 No up–shift to overdrive (After warm–up)

Road test while shifting manually with solenoid wire Faulty transmission
connector disconnected. Is there O/D up–shift in the D
position when shifting from L to 2 to D?

Yes
Connect solenoid wire connector, and while driving • Faulty transmission
does DLC1 TT terminal voltage rise from
OV to 7V in sequence? • Faulty solenoid

Are there 12V between ECM & terminals

2 and E1 when in the D position?

Yes

Are there 12V between ECM terminals l and

E1 when in the D position?

Yes

• Faulty Park/Neutral position switch circuit

• Faulty Park/Neutral position switch

Try another ECM

Is voltage between ECI1A terminals OD2 and E1 as • Faulty O/D main switch harness
follows?
O/D main switch turn 01V: 9–14V • Faulty O/D main switch
O/D main switch turn OFF: OV

Yes
Yes
Is voltage between ECM terminals OD1 and E1 as Try another ECM
follows?
Approx. 5V

Is voltage between ECIVI terminals OD1 and E1 Yes

Faulty cruise control ECU
normal with the cruise control ECU connector
pulled out?

Is voltage between ECM terminals L4 and E1 as Yes • Faulty ECM

follows?
Transfer shift position H2 or H4: 9 –14 V • Faulty cruise control wire harness
Transfer shift position L4: OV
• Faulty transfer position switch circuit
• Faulty transfer position switch
 AT2–35
A340H AUTOMATIC TRANSMISSION – TROUBLESHOOTING

Trouble No.4 No lock–up (After warm–up)

Warm up engine
Coolant temp.: 80°C (176°F)
ATF temp.: 50 – 80°C (122 –176°F)

Road test
Yes • Lock–up solenoid stuck
Connect a voltmeter to DLC1 terminals TT • Faulty transmission
and E1. Is there 7, 5 or 3V in the lock–up • Faulty lock–up mechanism
position while driving?

Is voltage between ECIM STP and E1 terminals as Faulty brake signal

follows?
Brake pedal depressed: 9–14V
Brake pedal released: OV

Is voltage between ECM terminals L4 and E1 Yes

Faulty throttle position signal
as follows?
Transfer shift position H2 or E–I4: 9 –14 V
Transfer shift position L4: OV

• Faulty transfer position switch circuit

• Faulty transfer position switch

Trouble No.5 Transfer gear no change L4 from H4

Check transfer position switch Bad

Faulty transfer position switch
(See page AT2–41)

Connect a voltmeter to DLC1 terminals TT and Faulty throttle position sensor

E1. Does TT terminal voltage vary with changes in the
throttle opening?

Yes

With the engine idling, is there 12V between ECM Try another ECM
terminals S4 and El, when transfer lever is shifted from
H4 to L4?

Yes
• No.4 solenoid stuck
• Faulty transfer
AT2–36
A340H AUTOMATIC TRANSMISSION – TROUBLESHOOTING

TT TERMINAL VOLTAGE INSPECTION

1. INSPECT THROTTLE POSITION SENSOR SIGNAL
(a) Turn the ignition switch to ON. Do not start the en-
gine.
(b) Connect a voltmeter to DLC1 terminals TT and E1.

(c) While slowly depressing the accelerator pedal,

check that TT terminal voltage rises in sequence.
If the voltage does not change in proportion to the
throttle opening angle, there is a malfunction in the
throttle position sensor or circuit.

2. INSPECT BRAKE SIGNAL

(a) Depress the accelerator pedal until the TT terminal
indicates 8 V.
(b) Depress the brake pedal and check the voltage
reading from the TT terminal.
Brake pedal depressed ............ 0 V
Brake pedal released ............. 8 V
If not as indicated, there is a malfunction in either the
stop light switch or circuit.

3. INSPECT EACH UP–SHIFT POSITION

(a) Warm up the engine.
Engine coolant temperature:
80° (176°F)
(b) Turn the O/D main switch to ’ON”.
(c) Place the pattern select switch in ”Normal” and the
shift lever into the D position.
(d) During a road test (above 10 km/h,6 mph) check
that voltage at the TT terminal is as indicated below
for each up–shift position.
If the voltage rises from 0 V to 7 V in the sequence
TT Terminal (V) Gear Position shown, the control system is okay.
The chart on the left shows the voltmeter reading and
corresponding gears.
 AT2–37
A340H AUTOMATIC TRANSMISSION – TROUBLESHOOTING

HINT: Determine the gear position by a light shock or

change in RPM when shifting. The lock –up clutch will
turn ON only infrequently during normal 2nd and 3rd
gear operation. To trigger this action, press the accel–
erator pedal to 50 96 or more of its stroke. At less than
50 96, the voltage may change in the sequence 2 V –
4V–6V–7V.
AT2–38
A340H AUTOMATIC TRANSMISSION – TROUBLESHOOTING

ELECTRONIC CONTROL COMPONENTS

INSPECTION
1. INSPECT VOLTAGE OF ECM CONNECTOR
(a) Remove the cowl side trim of passenger side.
(b) Turn the ignition switch ON.
(c) Measure the voltage at each terminal.

Terminal Measuring condition Voltage (V)

ransfer shift position H2 or H4

ransfer shift position L4
PWR pattern
NORM pattern
Brake pedal is depressed
Brake pedal is released
Engine coolant temp. 80°C (176°F)
Throttle valve fully closed
Throttle valve open
Throttle valve fully closed
Throttle valve fully open

O/D main switch turned ON

O/D main switch turned OFF

Cruise control main switch Standing still

OFF Vehicle moving
Standing still
Vehicle moving
 AT2–39
A340H AUTOMATIC TRANSMISSION – TROUBLESHOOTING

Terminal Measuring condition voltage (V)

N position
Except N position
2 position
Except 2 position
L position
Except L position
Transfer shift position H2 or H4
Transfer shift position Ld

Fluid temp. 20°C (68°F)

2. INSPECT SOLENOID
(a) Disconnect the connector from the ECM.
(b) Measure the resistance between S1, S2, SL, S4
and ground.
Resistance:
11 –15 Ω
(c) Apply battery positive voltage to each terminal.
Check that an operation noise can be heard from
the solenoid.

3. CHECK SOLENOID SEALS

If there is foreign material in the solenoid valve, there will
be no fluid control even with solenoid operation.
(a) Check the solenoid valves.
• Applying 490 kPa (5 kgf/cm2, 71 psi) of compressed
air, check that the solenoid valves do not leak.
• When supply battery positive voltage to the sole-
noids, check that the solenoid valves open.
(b) Check the lock–up solenoid valve.
• Applying 490 kPa (5 kgf/cm2, 71 psi) of compressed
air, check that the solenoid valve opens.
• When supply battery positive voltage to the sole-
noid, check that the solenoid valve does not leak the
air.
If a malfunction is found during voltage inspection
(step 1.), inspect the components listed below.
AT2–40
A340H AUTOMATIC TRANSMISSION – TROUBLESHOOTING

4. INSPECT PARK/NEUTRAL POSITION SWITCH

Inspect that there is continuity between terminals.
Tester condition
Shift position to terminal Specified value

5. INSPECT THROTTLE POSITION SENSOR

Using an ohmmeter, check the resistance between each
terminal.
Tester condition Throttle valve
to terminal condition Resistance (k
)

6. INSPECT N0.2 VEHICLE SPEED SENSOR

(a) Jack up the rear wheel on one side.
(b) Connect an ohmmeter between the terminals.
(c) Spin the wheel and check that the meter needle de-
flects from 0
to oo
.
7. INSPECT NO.1 VEHICLE SPEED SENSOR
(See page BE–48)
 AT2–41
A340H AUTOMATIC TRANSMISSION – TROUBLESHOOTING

8. INSPECT PATTERN SELECT SWITCH

Using an ohmmeter, check the continuity of the terminals
for each switch position.
HINT: As there are diodes inside, be careful of the tester
probe polarity.
Tester condition to
Switch position terminal number Specified vaIue

9. INSPECT ENGINE COOLANT TEMPERATURE

SENSOR
(See page EG2–246)

10. INSPECT O/D MAIN SWITCH

Using an ohmmeter, check the continuity of the terminals
for each switch position.
Tester condition to
Switch position terminal number Specified value

11. INSPECT TRANSFER POSITION SWITCH

Check that there is continuity between each terminal.
Tester condition to
Shift position terminal number Specified value

12. INSPECT TRANSMISSION AND TRANSFER FLUID

TEMPERATURE SENSOR
Measure the resistance between terminals.
Oil Temperature Resistance (
)
AT2–42
A340H AUTOMATIC TRANSMISSION – TROUBLESHOOTING

STALL TEST
The objective of this test is to check the overall performance of the transmission and engine by measur-
ing the stall speeds in the D and R positions.
NOTICE:
• Do the test at normal operating fluid temperature 50–80°C (122–176°F).
• Do not continuously run this test longer than 5 seconds.
• To ensure safety, conduct this test in a wide, clear, level area, which provides good traction.
• The stall test should always be carried out in pairs. One should observe the conditions of
wheels or wheel stoppers outside the vehicle while the other is doing the test.
MEASURE STALL SPEED
(a) Chock the front and rear wheels.
(b) Connect a tachometer to the engine.
(c) Fully apply the parking brake.
(d) Keep your left foot pressed firmly on the brake pedal.
(e) Shift the transfer lever to the H2 position.
(f) Start the engine.
(g) Shift into the D position. Step all the way down on the accelerator pedal with your right foot.
Quickly read the stall speed at this time.
NOTICE: Release the accelerator pedal and atop test If the rear wheels begin to rotate before the
engine speed reaches specified stall speed.
Stall speed:
2,850 ± 150 rpm
(h) Do the same test in R position.
EVALUATION
(a) If the stall speed is the same for both positions but lower than specified value:
Engine output may be insufficient
Stator one–way clutch is not operating properly
HINT: If more than 600 rpm below the specified value, the torque converter clutch could be faulty.
(b) If the stall speed in D position is higher than specified:
• Line pressure too low
• Forward clutch slipping
• No.2 one–way clutch not operating properly
• O/D one–way clutch not operating properly
• Transfer direct clutch slipping
(c) If the stall speed in R position is higher than specified:
• Line pressure too low
• Direct clutch slipping
• First and reverse brake slipping
• O/D one–way clutch not operating properly
• Transfer direct clutch slipping
(d) If the stall speed in both R and D positions are higher than specified:
• Line pressure too low
• Improper fluid level
• O/D one–way clutch not operating properly
• Transfer direct clutch slipping
 AT2–43
A340H AUTOMATIC TRANSMISSION – TROUBLESHOOTING
AT2–44
A340H AUTOMATIC TRANSMISSION – TROUBLESHOOTING

TIME LAG TEST

When the shift lever is shifted while the engine is idling, there will be a certain time lapse or lag before
the shock can be felt. This is used for checking the condition of the 0/D direct clutch, forward clutch,
direct clutch and first and reverse brake.
NOTICE:
• Do the test at normal operating fluid temperature 50–80°C (122–176°F).
• Be sure to allow one minute interval between tests.
• Make 3 measurements and take the average value.
MEASURE TIME LAG
(a) Fully apply the parking brake.
(b) Shift the transfer shift lever to the H2 position.
(c) Start the engine and check the idle speed.
Idle speed (N position and air conditioner OFF):
800 ± 50 rpm
(c) Shift the shift lever from N to D position. Using a stop watch, measure the time it takes from shifting
the lever until the shock is felt.
Time lag:
Less than 1.2 seconds
(d) In same manner, measure the time lag for N–R.
Time lag:
Less than 1.5 seconds
EVALUATION
(a) If N→D time lag is longer than specified:
• Line pressure too low
• Forward clutch worn
• O/D one–way clutch not operating properly
(b) If N→R time lag is longer than specified:
• Line pressure too low
• Direct clutch worn
• First and reverse brake worn
• O/D one–way clutch not operating properly
 AT2–45
A340H AUTOMATIC TRANSMISSION – TROUBLESHOOTING
AT2–46
A340H AUTOMATIC TRANSMISSION – TROUBLESHOOTING

HYDRAULIC TEST
PREPARATION
(a) Warm up the transmission fluid.
(b) Remove the transmission case test plug and connect the hydraulic pressure gauge.
SST 09992 – 00094
NOTICE:
• Do the test at normal operating fluid temperature 50–80°C (122–176°F).
• The line pressure test should always be carried out in pairs. One should observe the condi-
tions of wheels or wheel stoppers outside the vehicle while the other is doing the test.
MEASURE LINE PRESSURE
(a) Fully apply the parking brake and chock the 4 wheels.
(b) Start the engine and check idling speed.
(c) Keep your left foot pressed firmly on the brake pedal and shift into D position.
(d) Measure the line pressure when the engine is idling.
(e) Press the accelerator pedal all the way down. Quickly read the highest line pressure when engine
speed reaches stall speed.
NOTICE: Release the accelerator pedal and stop test if the rear wheels begin to rotate before the engine
speed reaches specified stall speed.
(f) In the same manner, do the test in R position.

Line pressure D position R position

Idling
Stall

If the measured pressures are not up to specified values, recheck the throttle cable adjustment and
do a retest.
 AT2–47
A340H AUTOMATIC TRANSMISSION – TROUBLESHOOTING

EVALUATION
(a) If the measured values at all positions are higher than specified:
• Throttle cable out of adjustment
• Throttle valve defective
• Regulator valve defective
(b) If the measured values at all positions are lower than specified:
• Throttle cable out of adjustment
• Throttle valve defective
• Regulator valve defective
• Oil pump defective
• O/D direct clutch defective
• Transfer direct clutch defective (H2, H4)
• Transfer front drive clutch defective (1–14, L4)
• Transfer low speed brake defective (1–4)
(c) If pressure is low in the D position only:
• D position circuit fluid leakage
• Forward clutch defective
(d) If pressure is low in the R position only:
• R position circuit fluid leakage
• Direct clutch defective
• First and reverse brake defective
AT2–48
A340H AUTOMATIC TRANSMISSION – TROUBLESHOOTING

ROAD TEST
NOTICE: Do this test at normal operating fluid tempera-
ture 50 – 80°C (122 –178°F).
HINT: The transmission shift points for the H2, H4 and
L4 transfer positions are different. Also the O/D gear and lock–
up are canceled when L4 is engaged.
1. D POSITION TEST IN NORM AND PWR PATTERN
POSITION
Shift into the D position and hold the accelerator pedal
constant at the full throttle valve opening position.
Check the following:
(a) 1 –2, 2–3 and 3–O/D up–shifts should take place,
and shift points should conform to those shown in
the automatic shift schedule.
Conduct a test under both Normal and Power pat-
tern.
HINT: There is no O/D up – shift or lock – up when the
coolant temperature is below 70°C (158°F).
EVALUATION
(1) If there is no 1–i2 up–shift:
• No.2 solenoid is stuck.
• 1– 2 shift valve is stuck.
(2) If there is no 2–3 up–shift:
• No.1 solenoid is stuck.
• 2–3 shift valve is stuck.
(3) If there is no 3–)0/D up–shift:
• 3–4 shift valve is stuck.
(4) If the shift point is defective:
• Throttle valve, 1– 2 shift valve, 2–3 shift valve,
• 3–4 shift valve etc., are defective.
(5) If the lock–up is defective:
• Lock–up solenoid is stuck.
• Lock–up relay valve is stuck.

(b) In the same manner, check the shock and slip at the
1→2 , 2→3, and 3→O/D up–shifts.
EVALUATION
If the shock is excessive:
• Line pressure is too high.
• Accumulator is defective.
• Check ball is defective.
 AT2–49
A340H AUTOMATIC TRANSMISSION – TROUBLESHOOTING

(c) Run at the D position lock–up or 0/D gear and check

for abnormal noise and vibration.
HINT: The check for the cause of abnormal noise and
vibration must be made with extreme care as it could also
be due to loss of balance in the propeller shaft, differen–
tial, torque converter clutch, etc.

(d) While running in the D position, 2nd, 3rd and 0/D

gears, check to see that the possible kick–down ve-
hicle speed limits for 2→1, 3→2 and O/D→3 kick-
downs conform to those indicated on the automatic
shift schedule.
(e) Check for abnormal shock and slip at kick–down.

(f) Check for the lock –up mechanism.

(1) Drive in D position, O/D gear, at a steady speed
(lock–up ON) of about 75 km/h (47 mph).
(2) Lightly depress the accelerator pedal and check
that the engine RPM does not change abruptly.
If there is a big jump in engine RPM, there is no lock–
up.

2. 2 POSITION TEST
Shift into the 2 position and, while driving with the accelerator
pedal held constantly at the full throttle
valve opening position, push in one of the pattern
selectors and check on the following points.
(a) Check to see that the 1→2 up–shift takes place and that
the shift point conforms to that shown on the automatic
shift schedule.
HINT:
• There is no O/D up–shift and lock–up in the 2 position.
• To prevent overrun, the transmission up–shifts into 3rd
gear at around 100 km/h (62 mph) or more.
AT2–50
A340H AUTOMATIC TRANSMISSION – TROUBLESHOOTING

(b) While running in the 2 position and 2nd gear, re-

lease the accelerator pedal and check the engine
braking effect.
EVALUATION
If there is no engine braking effect:
• Second coast brake is defective.

(c) Check for abnormal noise during acceleration and

deceleration, and for shock at up–shift and down-
shift.

3. L POSITION TEST
(a) While running in the L position, check to see that
there is no up–shift to 2nd gear.

(b) While running in the L position, release the acceler-

ator pedal and check the engine braking effect.
EVALUATION
If there is no engine braking affect:
• First and reverse brake is defective.

(c) Check for abnormal noise during acceleration and

deceleration.
 AT2–51
A340H AUTOMATIC TRANSMISSION – TROUBLESHOOTING

4. R POSITION TEST
Shift into the R position and, while starting at full throttle,
check for slipping.

5. P POSITION TEST
Stop the vehicle on a gradient (more than 5°) and after
shifting into the P position, release the parking brake.
Then check to see that the parking lock pawl holds the
vehicle in place.

6. TRANSFER TEST
(a) When the shift lever is shifted from the H2 to H4,
confirm that the vehicle changes from 2 to 4 wheel
drive. If it does not, the transfer is faulty.

(b) When the transfer lever is shifted from H4 to L4,

confirm that the gear changes according to the shift
diagram (See page AT2–54). If it does not, the No.4
solenoid, ECM or transfer is faulty.
AT2–52
A340H AUTOMATIC TRANSMISSION – TROUBLESHOOTING

AUTOMATIC SHIFT SCHEDULE

SHIFT POINT (Transfer shift position ”H2” or ’H4”)

Shift position Shifting point Vehicle speed km/h (mph)

Throttle valve fully opened

D (NORM)

Throttle valve fully closed

Throttle valve fully opened

D (PWR)

Throttle valve fully closed

Throttle valve fully opened

2 (NORM and PWR)

Throttle valve fully opened

L (NORM and PWR)

LOCK– UP (Transfer shift position ”H2” or ’H4’)

D position
Throttle valve opening 596

’3rd Gear
O/D Gear (NORM)
O/D Gear (PWR)

*: O/D main switch OFF

HINT:
(1) Lock –up will occur in 2nd gear unless the throttle valve opening is greater than 50%.
(2) There is no lock–up in the 2 and L positions.
(3) In the following cases, the lock–up will be released regardless of the lock–up pattern.
• When the throttle is completely closed.
When the stop light switch is ON.
 AT2–53
A340H AUTOMATIC TRANSMISSION – TROUBLESHOOTING

TRANSFER HIGH–LOW SHIFT POSITION

The A340H transfer differs from previous manual transfer in
that high–low shifting is possible while the vehicle is in motion,
though it is not possible at all vehicle speeds or throttle opening
angles. The shifting possibility positions for high–low shifting
have been adopted with the idea of improving shifting perfor-
mance and transfer conditions, and preventing engine over-
run.
The shifting possibility positions are controlled by the
ECM and when a high–low shift change is made within these
positions, the ECM operates the No.4
solenoid which carries out the high – low transfer shift. Howev-
er, if a transfer is attempted outside the shifting possibility posi-
tion, the high–low shift will not take place until the vehicle
speed and throttle opening angle come within the appropriate
position.
The high–low shifting possibility positions are shown in the dia-
grams below.
There are 3 shifting possibility positions for when the transmis-
sion gear is in 1 st, 2nd or 3rd gear, which combine with the re-
spective transmission shift positions (L. 2, D).
Although the high → low shift takes place in the 1 st gear, 2nd
gear and 3rd gear shifting positions with the gears in 1 st gear,
2nd gear and 3rd gear respectively, when a high → low shift
change is made in 1 st gear while in the 2nd gear shifting possi-
bility position only
after the transmission has shifted up into 2nd gear does the
high → low shift take place.
In the 2 position and D position high → low shifting possibility
positions where the 1 st and 2nd positions overlap, the high →
low shift will take place in 1 st gear if the transmission is in 1 st
gear, or in 2nd gear if the transmission is in 2nd gear.
AT2–54
A340H AUTOMATIC TRANSMISSION – TROUBLESHOOTING

L Position: High – Low Shift Possibility

Range
 AT2–55
A340H AUTOMATIC TRANSMISSION – TROUBLESHOOTING
AT2–56
A340H AUTOMATIC TRANSMISSION – TROUBLESHOOTING