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
Page 479 of 2389

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
Page 480 of 2389
INSPECTION OF ELECTRONIC CONTROL
COMPONENTS
1. (A540E)
INSPECT VOLTAGE OF TCCS ECU CONNECTOR
(a) Turn on the ignition switch.
(b) Measure the voltage at each terminal.
Coolant temp. 176°F (84°C)
Cruise control main
switch OFFO/D main switch turned OFF O/D main switch turned ON Throttle valve fully closed
Throttle valve fully closed Brake pedal is depressed
Throttle valve fully openMeasuring condition
Brake pedal is released
Throttle valve open
Vehicle movingVehicle moving P, R or N range D, 2 or L range
Standing stillStanding still NORM patternVoltage (V)
PWR pattern Terminal
± AUTOMATIC TRANSAXLE(A540E and A540H)AT±216
Page 482 of 2389
3. (A540E)
INSPECT SOLENOID VALVES
(a) Disconnect the connector from Engine and ECT ECU
(b) Measure the resistance between S1, S2, SL and
body ground.
Resistance: 11 ± 15
(e) Apply battery voltage to each terminal.
Check that an operation noise can be heard from
the solenoid.
Center differential control switch AUTO position
Center differential control switch AUTO position Center differential control switch turned OFF
Center differential control switch turned OFF Coolant temp. below 122°F950°0 Throttle valve fully closed to fully open
Coolant temp. above 122°F (50°C0 O/D main switch turned OFF O/D main switch turned ON
Brake pedal is depressed
Brake pedal is releasedMeasuring condition
Except 2 range
Except N range Except P range
Except L range
NORM patternVoltage (V)
PWR pattern Terminal
N range2 range P range
L range
± AUTOMATIC TRANSAXLETroubleshooting (Electronic Control System) (A540E and
A540H)AT±218
Page 491 of 2389

COMPONENT PARTS
General Notes
The instructions here are organized so that you work on only one component group at a time.
This will help avoid confusion from similar±looking parts of different subassemblies being on your
workbench at the same time.
The component groups are inspected and repaired from the converter housing side.
As much as possible, complete the inspection, repair and assembly before proceeding to the next
component group. If a component group can not be assembled because parts are being ordered,
be sure to
keep all parts of that group in a separate container while proceeding with disassembly, inspection,
repair and assembly of other component groups.
Recommended fluid for the automatic transaxle: A540E ATF DEXRONII
A540H ATF Type T or equivalent
Recommended oil for the transfer: Transaxle oil E50, API GL5, SAE 75W±90 or equivalent
GENERAL CLEANING NOTES:
1. All disassembled parts should be washed clean, with any fluid passages and holes blown through with
compressed air.
2. When using compressed air to dry parts, always aim away from yourself to prevent accidentally spraying
automatic transaxle fluid or kerosene in your face.
3. The recommended automatic transaxle fluid or kerosene should be used for cleaning.
PARTS ARRANGEMENT:
1. After cleaning, the parts should be arranged in proper order to allow efficient inspection, repairs, and reas-
sembly.
2. When disassembling a valve body, be sure to keep each valve together with the corresponding spring.
3. New brakes and clutches that are to be used for replacement must be soaked in transaxle fluid for at least
fifteen minutes before assembly.
GENERAL ASSEMBLY:
1. All oil seal rings, clutch discs, clutch plates, rotating parts, and sliding surfaces should be coated with
transmission fluid prior to reassembly.
2. All gaskets and rubber O±rings should be replaced.
3. Make sure that the ends of a snap ring are not aligned with one of the cutouts and are installed in the
groove correctly.
4. If a worn bushing is to be replaced, the subassembly containing that bushing must be replaced.
5. Check thrust bearings and races for wear or damage. Replace if necessary.
6. Use petroleum jelly to keep parts in place.
± AUTOMATIC TRANSAXLEComponent Parts (General Notes) (A540E and A540H)AT±262
Page 492 of 2389
DISASSEMBLY OF SECOND COAST BRAKE
PISTON
1. REMOVE OIL SEAL RING
Remove the oil seal ring from the piston.
2. REMOVE PISTON ROD
(a) Remove the E±ring while pushing the piston with
needle±nose pliers.
COMPONENT PARTS
Second Coast Brake
± AUTOMATIC TRANSAXLEComponent Parts (Second Coast Brake) (A540E and
A540H)AT±263
Page 493 of 2389
ASSEMBLY OF SECOND COAST BRAKE
PISTON
1. SELECT PISTON ROD
If the band is OK but piston stroke not within the standard value,
select the piston rod.
Piston stroke: 2.0 ± 3.5 mm (0.079 ± 0.138 in.)
There are two lengths of piston rod.
Piston rod length: 95.2 mm l3.748 in.)
96.3 mm (3.791 in.)
2. INSTALL PISTON ROD
(a) Install the plate washer and inner spring to the piston
rod. INSPECTION OF SECOND COAST BRAKE
COMPONENT
If the lining of the brake band is exfoliated or discol-
ored,
or even part of the printed marks is defaced, replace the
brake band.(b) Remove the inner spring, plate washer and pis-
ton rod.
(b) Install the E±ring while pushing the piston.
± AUTOMATIC TRANSAXLEComponent Parts (Second Coast Brake) (A540E and
A540H)AT±264