1986 TOYOTA CAMRY V20 turn signal

VALVE BODY
Hydraulic Control System

A540E, A540H
The hydraulic control system is composed of the oil pump, the valve body, the solenoid valves, the accu-
mulators, the clutches and brakes, and the governor valve as well as the fluid passages which connect all
of these components.
Based on the hydraulic pressure created by the oil pump, the hydraulic control system governs the hy-
draulic pressure acting on the torque converter, clutches and brakes in accordance with the vehicle driving
conditions.
There are three solenoid valves on the valve body.
The No. 1 and No. 2 solenoid valves are turned on and off by signals from ECU to operate the shift valves
and change the gear shift position.
The No. 3 solenoid valve is operated by signals from the ECU to engage or disengage the lock-up clutch
of the torque converter.

A540H
There are two center differential control solenoid valves on the transfer.
The solenoid valves are adjusting the center differential control pressure.
HYDRAULIC CONTROL SYSTEM
Hydr. pressure control
OIL PUMP
CLUTCHES & BRAKESFluid passage switchingPlanetary gear unit
Torque converter
Throttle Cable
SOLENOID VALVES
ECU
AT-8- AUTOMATIC TRANSAXLEOperation

Diagnosis System (A140E)
DESCRIPTION
1. A self±diagnosis function is built into the electrical control system.
Warning is indicated by the overdrive OFF indicator.
HINT: Warning and diagnostic codes can be read only when
the overdrive switch is ON. If OFF, the overdrive OFF
indicator is lit continuously and will not blink.
(a) If a malfunction occurs within the speed sensors (No.
1 or 2) or solenoids (No. 1 or 2), the overdrive OFF
light will blink to. warn the driver. .
However, there will be no warning of a malfunction with
lock±up solenoid.
(b) The diagnostic code can be read by the number of blinks of
the overdrive OFF indicator when terminals
Tt and E1 are short±circuited. (See page AT±17)
tc) The throttle position sensor or brake signal are not indi-
cated, but inspection can be made by checking the voltage at
terminal Tt of the check connector (diagnosis).
(d) The signals to each gear can be checked by measuring the
voltage at terminal Tt of the check connector while driving.
2. The diagnostic (malfunction) code is retained in memory by the
CPU and due to back±up voltage, is not canceled out when the
engine is turned off. Consequently, after repair, it is necessary
to turn the ignition switch off and remove the fuse EFI (15A) or
disconnect the ECT computer connector to cancel out the diag-
nostic (malfunction)
code. (See page AT±18)
HINT:
wLow battery voltage will cause faulty operation of the diag-
nosis system. Therefore, always check the battery first.
w Use a voltmeter and ohmmeter that have an impedance
of at least 10 k 11 IV.
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 switch is
placed at OFF.
3. When the O/D switch is set to ON, the O/D OFF light
should go out.
If the O/D OFF light flashes when the O/D switch is set
to ON, the electronic control system is faulty.
± AUTOMATIC TRANSAXLETroubleshooting (Diagnosis System) (A140E)AT±16

3. INSPECT EACH UP±SHIFT POSITION
(a) Warm up the engine.
Coolant temperature: 176
°F (80°C)
(b) Turn the O/D switch to ºONº.
(c) Place the pattern select switch in ºNormalº and the shift
lever into the D range.
(d) During a road test (above 10 km/h or 6 mph) check that
voltage at the ECT terminal is as indicated below for
each up±shift position.
If the voltage rises from 0V to 7V in the sequence
shown, the control system is okay.
The chart on the left shows the voltmeter reading and
corresponding gears. .
HINT: Determine the gear position by a light shock or
change in engine 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 acceler-
ator pedal to 50% or more of its stroke. At less than
50%, the voltage may change in the sequence 2V ± 4V
± 6V ± 7V. 2. INSPECT BRAKE SIGNAL
(a) Depress the accelerator pedal until the ECT terminal
indicates 8V.
(b) Depress the brake pedal and check the voltage read-
ing from the ECT terminal.
(c) Brake pedal depressed . . . . . . . . . . 0V
Brake pedal released . . . . . . . . . . . . 8V
If not as indicated, there is a malfunction in either the
stop light switch or circuit.
INSPECTION OF Tt TERMINAL VOLTAGE
1. INSPECT THROTTLE POSITION SENSOR SIGNAL
(a) Turn the ignition switch to ON. Do not start the engine.
(b) Connect a voltmeter to terminals Tt and E1.
(c) While slowly depressing the accelerator pedal,
check that ECT 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.
± AUTOMATIC TRANSAXLETroubleshooting (Electronic Control System) (A140E)AT±31

(e) Turn the O/D switch ON.
(d) Select the normal pattern.
(e) Drive .at around 50 km/h (31 mph) to where 7, 5 or 3
volts appears on the voltmeter (this is the lock±up
range) .
(f) Depress the accelerator pedal and read the tachometer.
If there is a big jump in engine rpm there is not lock±
up. 8. INSPECT PATTERN SELECTION SWITCH
Inspect that there is continuity between 5 and each ter-
minal. .
HINT: As there are diodes inside, be careful of the test-
er probe polarity.
10. INSPECT LOCK±UP MECHANISM
(a) Warm up the coolant and ATF.
(b) Connect a voltmeter to the check connector terminals
Tt and E1.
11. INSPECT BRAKE SIGNAL
Check that the brake light comes on when the brake
pedal is depressed. 9. INSPECT O/D SWITCH
Inspect that there is continuity between terminals 1 and 3.
S/W positionTerminal
Terminal Pattern
NORM
PWR
OFF
± AUTOMATIC TRANSAXLETroubleshooting (Electronic Control System) (A140E)AT±35

Diagnosis System
DESCRIPTION
1. A self±diagnosis function is. built into the electrical control
system. Warning is indicated by the overdrive OFF indicator.
HINT: Warning and diagnostic codes can be read only when
the overdrive switch is ON. If OFF, the overdrive OFF
indicator is lit continuously and will not blink.
(a) If a malfunction occurs within the speed sensors or sole-
noids, the overdrive OFF light will blink to warn the driver.
However, there will be no warning of a malfunction with
lock±up solenoid.
W The diagnostic code can be read by the number of
blinks of the overdrive OFF indicator when terminals
Tt and E1 are short±circuited. (See page AT± 191)
(c) The throttle position sensor or brake signal are not indicated,
but inspection can be made by checking the voltage at ter-
minal Tt of the check connector.
(d) The signals to each gear can be checked by measuring the
voltage at terminal Tt of the check connector while driving.
2. The diagnostic (malfunction) code is retained in memory by the
ECU and due to back±up voltage, is not canceled out when the
engine is turned off. Consequently, after repair, it is necessary
to turn the ignition switch off and remove the fuse EFI (15A)
(A540E) or DOME (20A)
(A540H) or disconnect the Engine and ECT ECU (A540E)
or ECT ECU (A540H) connector to cancel out the diagnostic
(malfunction) code. (See page AT±192)
HINT:
wLow battery voltage will cause faulty operation of the diag-
nosis system. Therefore, always check the battery first.
wUse a voltmeter and ohmmeter that have an impedance 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 switch
placed at OFF.
3. When the O/D switch is set to ON, the O/D OFF light should go
out.
If the O/D OFF light flashes when the O/D switch is set to
ON, the electronic control system is faulty.
± AUTOMATIC TRANSAXLETroubleshooting (Diagnosis System) (A540E and A540H)AT±190

3. INSPECT EACH UP±SHIFT POSITION
(a) Warm up the engine.
Coolant temperature: 176
°F (80°)
(b) Turn the O/D switch to ºONº.
(c) Place the pattern select switch in ºNormalº and the shift
lever into the D range.
(d) During a road test (above 10 km/h or 6 mph) check that volt-
age at the Tt terminal is as indicated below for each up±
shift position.
If the voltage rises from 0V to 7V in the sequence shown,
the control system is okay.
The chart on the left shows the voltmeter reading and cor-
responding gears.
HINT: Determine the gear position by a fight shock or
change in engine 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 accelerator pedal
to 50% or more of its stroke. At less than 50%, the voltage
may change in the sequence 2v ± 4V ± 6V ± 7V. 2. INSPECT BRAKE SIGNAL
(a) Depress the accelerator pedal until the Tt terminal indi-
cates 8V.
(b) Depress the brake pedal and check the voltage read-
ing from the Tt terminal.
Brake pedal depressed ...... 0V
Brake pedal released . . . . . . . . 8V
If not as indicated, there is a malfunction in either the
stop light switch or circuit.
INSPECTION OF ECT OR Tt TERMINAL
VOLTAGE
1. INSPECT THROTTLE POSITION SENSOR SIGNAL
(a) Turn the ignition switch to ON. Do not start the engine.
(b) Connect a voltmeter to 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.
± AUTOMATIC TRANSAXLETroubleshooting (Electronic Control System) (A540E and
A540H)AT±215

Fusible link blown
Headlight control relay faulty
Light control/dimmer switch faulty
Daytime running light relay faulty
(CANADA)
Headlight dimmer relay faulty
(CANADA)
Wiring or ground faulty
Replace fuse and check for short
Replace fusible fink
Check relay
Check switch
Check relay
Repair as necessary TAIL fuse blown
Fusible link blown
Taillight control relay faulty
Light control switch faulty
Daytime running light relay faulty
(CANADA)
Wiring or ground faulty Light control/dimmer switch faulty
Daytime running light relay faulty
(CANADA)
Headlight dimmer relay faulty
(CANADA)
Wiring or ground faultyReplace fusible link
Check relay
Check switch
Check relay
Check relay
Repair as necessary
Replace fuse and check for short
Check flasher
Check switch
Repair as necessary
Replace fuse and check short
Check flasher
Check switch
Repair as necessary HAZ±HORN fuse blown
Turn signal flasher faulty
Hazard warning switch faulty
Wiring or ground faultyCheck switch
Check relay
Check relay
Repair as necessary
Replace fuse and check for short
Adjust or replace switch
Repair as necessary
TURN fuse blown
Turn signal flasher faulty
Turn signal switch faulty
Wiring or ground faulty
LIGHTING
Troubleshooting
STOP fuse blown
Stop light swtich faulty
Wiring or ground faulty Light bulb burned out
Socket, wire or ground faulty
High beam headlights or
headlight flashers do not
operate
Light control rheostat faulty
Wiring or ground faulty Instrument lights do not
light (taillights light)Tail, parking and
license light do not
light
Turn signal switch faulty
Wiring or ground faulty
Hazard warning lights do
not operateReplace bulb
Repair as necessary
Headlights do not light
Check switch
Repair as necessaryCheck rheostat
Repair as necessary Only one light comes
ON
Turn signal does not
flash on one side
Turn signals do not
operateBE±3
BE±3
BE±18
BE±15
BE±25
Adjust or replace switch
Stop light switch faultyBE±3
BE±18
BE±15
BE±25
Stop lights do not light
Stop lights stay on
BE±3
BE±19
BE±19BE±3
BE±19
BE±15
Possible cause
BE±15
BE±25
BE±3
BE±89
RemedyProblem
BE±15BE±23 BE±89BE±25
BE±25Page
± BODY ELECTRICAL SYSTEMLightingBE±14

Light Control Switch, Headlight
Dimmer Switch and Turn Signal
Switch
INSPECTION OF SWITCHES
INSPECT SWITCHES CONTINUITY
Inspect the switch continuity between terminals.
Light control switch
If continuity is not as specified, replace the
switch.
Headlight dimmer switch
Turn signal switch
Switch position
Switch position
Switch positionHigh Beam
Right TurnLow Beam
TerminalTerminal
Terminal
Left Turn
NeutralHEAD
FlashTAIL
OFF
± BODY ELECTRICAL SYSTEMLightingBE±15