Page 463 of 2389

ROAD TEST (A540E and A540H)
NOTICE: Perform the test at normal operating fluid temperature
(122 ± 176°F or 50 ± 80°C).
1. D RANGE TEST IN NORM AND PWR PATTERN
RANGES
Shift into the D range 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. (See page AT±230)
Conduct a test under both Normal and Power. patterns.
HINT:
wThere is no O/D up±shift and lock±up when the coolant
temp. is below 140
°F (60°C) (A540E) or 122°I= (50°C)
(A540H).
wWhen the coolant temp. is below 140°F (600C) or
122°F (50°C) (A540H), the shift point is lower than specified in
the automatic shift schedule.
EVALUATION
(1) If there is no 1 ± 2 up±shift:
wNo. 2 solenoid is stuck
w1±2 shift valve is stuck
(2) If there is no 2 ± 3 up±shift:
wNo. 1 solenoid is stuck
w2±3 shift valve is stuck
(3) If there is no 3 ± O/D up±shift:
w3±4 shift valve is stuck
(4) If the shift point is defective:
wThrottle valve, 1±2 shift valve, 2±3 shift valve, 3±4
shift valve etc., are defective
(5) If the lock±up is defective:
wLock±up solenoid is stuck .
wLock±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:
wLine pressure is too high
wAccumulator is defective
wCheck ball is defective
(c) Run at the D range lock±up or 0/C) gear and check for abnor-
mal noise and vibration.
HINT: The check for the cause of abnormal noise and vibra-
tion must be make with extreme care as it could also be due
to loss of balance in the drive shaft, tire, torque converter,
etc.
± AUTOMATIC TRANSAXLETroubleshooting (Mechanical System Tests) (A540E and
A540H)AT±227
Page 466 of 2389
*: O/D switch OFF
HINT:
(1) Lock±up will not occur in 2nd gear unless the throttle valve opening is greater than 50%.
(2) There is no lock±up in the 2 and L ranges.
(3) In the following cases, the lock±up will be released regardless of the lock±up pattern.
wWhen the throttle is completely closed.
wWhen the brake light switch is ON.
(4) When the coolant. temp. is below 140
°F (60°C) (A540E) or 122°F (50°C) (A540H), the shift point is lower
than specified vehicle speed.
Automatic Shift Schedule
(A540E)
Throttle valve opening 5%
Throttle valve opening 5%Throttle valve fully open
Throttle valve fully open
*: O/D switch
OFF
(A540H)
Lock±up ON[fully closed]
Lock±up OFFkm/h (mph) Lock±up OFFkm/h (mph)
[fully closed]
km/h (mph)
Lock±up ONkm/h (mph) NORM
PWR NORM
PWR
NORM
PWRNORM
PWR
D range D range
D range
2 range
D range
2 range
L range
L rangeNORM
NORM NORM
NORM
PWR PWR PWR
PWR
± AUTOMATIC TRANSAXLETroubleshooting (Automatic Shift Schedule) (A540E and
A540H)AT±230
Page 471 of 2389

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
Page 472 of 2389
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
Page 474 of 2389
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
Page 475 of 2389

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
Page 476 of 2389
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
Page 478 of 2389
Road test
Connect a voltmeter to terminals Tt and E,.
Is there 7, 5 or 3V in the lock±up range while driv-
ing?
Is voltage between ECT ECU BK and GND
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)
Trouble No. 4 No lock±up (After warm±up)
w Lock±up solenoid stuck
wFaulty transaxle
wFaulty lock±up mechanism
wFaulty ECU power source and ground
wFaulty throttle position signalFaulty brake signal
Ye sYe s
± AUTOMATIC TRANSAXLETroubleshooting (Electronic Control System) (A540E and
A540H)AT±214