engine coolant TOYOTA CAMRY V20 1986 Service Information

Disconnect ECT ECU connector and road test.
Does the transaxle operate i n the respective gear
when in the following ranges while driving?
D range . . Overdrive
2 range . . 3 rd gear
L range . . . 1 st gear
TROUBLESHOOTING FLOW±CHART
Trouble No.1 No Shifting
Connect a voltmeter to the check connector termi-
nals Tt and E1.
Does ECT terminal voltage vary with changes in
throttle opening?
Is voltage between ECT ECU terminals
BK and GND as follows?
0V: Brake pedal released
10 ± 14 V: Brake pedal depressed Warm up engine
Coolant temp.: 17f6°F (80°C)
ATF temp.: 122 ± 176°F (50 ± 80°C)
wECU power source and ground faulty
wThrottle position signal faulty
wECT terminal wire open or short
Ye s
Continued on page AT±27Brake signal
faulty
Transaxle faulty Ye s
Ye s
± AUTOMATIC TRANSAXLETroubleshooting (Electronic Control System) (A±1 40E)AT±26

Connect a voltmeter to the check connector
terminals Tt and El.
Does ECT terminal voltage vary with changes in throttle
opening?
Check voltage between ECT ECU terminals
PWR and GND.
Power pattern: 10 ± 14V
Normal pattern: 1VIs voltage between ECT ECU terminals
BK and GND as follows?Tt
0V: Brake pedal released
10 ± 14V: Brake pedal depressed Warm up engine
Coolant temp.: 176°F (80°C)
ATF temp.: 122 ± 176°F (50 ± 80°C)
wECU power source and ground faulty
wThrottle position signal faulty
wECT terminal wire open or short
Faulty pattern select switch system
Shift point too high or too low
wFaulty ECT ECU
w|Faulty transaxle
Trouble No. 2
Brake sig-
nal faulty Ye s
Ye s
± AUTOMATIC TRANSAXLETroubleshooting (Electronic Control System) (A140E)AT±28

Road test
Connect a voltmeter to the check connector
terminals Tt and El.
Is there 7, 5 or 3 V in the lock±up range while driving?
Is voltage between ECT ECU Terminals
BK and GND as follows?
Brake pedal depressed: 10 ± 14V
Brake pedal released: 0V Warm up engine ,
Coolant temp.: 176°F (80°C)
ATF temp.: 122 ± 176°F (50 ± 80°C)
wLock±up solenoid stuck
wFaulty transmission
wFaulty lock±up mechanism
wFaulty ECU power source and ground
w Faulty throttle position signal
No lock±up (After warm±up)
Faulty brake signal Trouble No. 4
Ye s
Ye s
± AUTOMATIC TRANSAXLETroubleshooting (Electronic Control System) (A140E)AT±30

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

Disconnect solenoid wire connector and road test.
Does the transaxle operate in the respective gear
when in the following ranges while driving?
D range .... Overdrive
2 range .... Overdrive
L range .... 1 st gear
TROUBLESHOOTING FLOW±CHART (A540E)
Trouble No. 1 No Shifting
Is voltage between Engine and ECT ECU
terminals BK and E1 as follows?
0V: Brake pedal released
10 ± 14V: Brake pedal depressed
Connect solenoid wire connector and road test.
Does Tt terminal voltage rise from 0V to
7V in sequence?Warm up engine
Coolant temp.: 176°F (80°C)
ATF temp.: 122 ± 176°F (50 ± 80°C)
Connect a voltmeter to terminals Tt and E1.
Does Tt terminal voltage vary with changes in
throttle opening? (See page AT±215)
wECU power source and ground faulty
wThrottle position signal faulty
wTt terminal wire open or short
Are there 10 ± 14V between
Engine and ECT ECU terminals 2 ± E
when in the D range?
Are there 10 ± 14V between Engine and ECT
ECU terminals L ± Ex when in the D range?
wNeutral start switch circuit faulty
wNeutral start switch faultyProceed to trouble No. 3
(See page AT±209)
Try another Engine and ECT ECUw Transaxle faulty
wSolenoid faultyBrake signal faulty
Transaxle faulty
Ye s
Ye s
Ye s
Ye s Ye s
± AUTOMATIC TRANSAXLETroubleshooting (Electronic Control System) (A540E and
A540H)AT±207

Check voltage between Engine and ECT ECU
terminals PWR and E1.
Power pattern: 10 ± 14V
Normal pattern: 1VIs voltage between Engine and ECT ECU
terminals BK and E1 as follows?
0V: Brake pedal released
1V: Brake pedal depressed Warm up engine
Coolant temp.: 176°F (80°C)
ATF temp.: 122 ± 176°F (50 ± 80°C)
Connect a voltmeter to terminals Tt and El.
Does Tt terminal voltage vary with changes in
throttle opening? (See page AT±215)
ECU power source and ground faulty
Throttle position signal faulty
Tt terminal wire open or short
Faulty Engine and ECT ECU
Faulty transaxle
Shift point too high or too Low
Faulty pattern select switch systemBrake signal
faulty
Trouble No. 2
Ye s Ye s
± AUTOMATIC TRANSAXLETroubleshooting (Electronic Control System) (A540E and
A540H)AT±208

Road test
Connect a voltmeter to terminals Tt and El.
Is there 7, 5 or 3V in the lock±up range while driv-
ing?
Is voltage between Engine and ECT ECU BK
and E1 terminals as follows?
Brake pedal depressed: 10 ± 14V
Brake pedal released: OV Warm up engine
Coolant temp.: 176°F (80°C)
ATF temp.: 122 ± 176°F (50 ± 80°C)
wFaulty ECU power source and ground
wFaulty throttle position signalwLock±up solenoid stuck
wFaulty transaxle
w Faulty lock±up mechanism
No lock±up (After warm±up)
Faulty brake signal
Trouble No. 4
Ye sYe s
± AUTOMATIC TRANSAXLETroubleshooting (Electronic Control System) (A540E and
A540H)AT±210

Disconnect solenoid wire connector and road test.
Does the transaxle operate in the respective gear
when in the following ranges white driving?
D range .... Overdrive
2 range .... Overdrive
L range .... 1 st gear
TROUBLESHOOTING FLOW±CHART (A540H)
Trouble No. 1 No Shifting
Is voltage between ECT ECU terminals BK
and GND as follows?
0V: Brake pedal released
10 ± 14V: Brake pedal depressed
Connect solenoid wire connector and road test.
Does Tt terminal voltage rise from OV to 7V in se-
quence?Warm up engine
Coolant temp.: 176°F (80°C)
ATF temp.: 122 ± 176°F (50 ± 80°)
Connect a voltmeter to terminals Tt and E1.
Does Tt terminal voltage vary with changes in
throttle opening? (See page AT±215)
wECU power source and ground faulty
wThrottle position signal faulty
wTt terminal wire open or short
Are there 10 ± 14V between ECT
ECU terminals 2L ± GND when in the
D range?
Are there 10 ± 14V between ECT ECU
terminals LL ± GND when in the D range?
wNeutral start switch circuit faulty
wNeutral start switch faultyProceed to trouble No. 3
(See page AT±227) Transaxle faulty
Solenoid faulty
Try another ECT ECUBrake signal
faulty
Transaxle faulty
Ye s
Ye s
Ye s Ye s
Ye s
± AUTOMATIC TRANSAXLETroubleshooting (Electronic Control System) (A540E and
A540H)AT±211

Is voltage between ECT ECU terminals BK
and GND as follows? .
0V: Brake pedal released
10 ± 14V: Brake pedal depressed
Check voltage between ECT ECU terminals
P and GND.
Power pattern: 10 ~ 14V
Normal pattern: 1 V Warm up engine
Coolant temp.: 176°F (80°C)
ATF temp.: 122 ± 176°F (50 ± 80°C)
Connect a voltmeter to terminals Tt and E1.
Does Tt terminal voltage vary with changes in
throttle opening? (Seepage AT±21 5)
ECU power source and ground faulty
Throttle position signal faulty
Tt terminal wire open or short
Faulty pattern select switch system
Shift point too high or too low
Faulty ECT ECU
Faulty speed sensorBrake signal
faulty
Trouble No. 2
Ye s
Ye s
± AUTOMATIC TRANSAXLETroubleshooting (Electronic Control System) (A540E and
A540H)AT±212