21-202AUTOMATIC TRANSAXLE - Troubleshooting
CONVERTER STALL TESTStall test consist of determining maximum engine
speed obtained at full throttle in “D” and “R”
positions. This test checks torque converter stator
overrunning clutch operation, and holding ability of
transaxle clutches and low-reserve brake.
CautionDuring this test, make sure that no one stand in
front of or behind vehicle.
1. Check transaxle fluid level. Fluid should be at
normal operating temperature
[70-80°C (160-
18O”F)]. Engine coolant should also be at normaloperating temperature
[80-90°C (180- 19O”F)l.2. Apply chocks to both rear wheels.
3. Attach engine tachometer.
4. Apply parking and service brakes fully.
5. Start engine.
6. With selector lever in “D” position, depress
accelerator pedal fully to read engine maximum
rpm. Do not hold throttle wide open any longer
than is necessary to obtain maximum engine
rpm reading, and never longer than 5 seconds ata time. If more than one stall test is required,
operate engine at approximatey 1,000 rpm in
neutral for 2 minutes to cool transaxle fluid
between tests.
Stall speed:
1,800-3,200 rpm
TRANSAXLE CONTROL7. Place selector lever to “R” position and perform
?+stall test by the same procedure as in foregoing
-,
item.Stall Speed Above Specification in “D”
If stall speed is higher than specification, rear clutchor overrunning clutch of transaxle is slipping. In this
case, perform hydraulic test to locate cause of
slippage.Stall Speed Above Specifjcation in “R”
If stall speed is higher than specification, front
clutch of transaxle or low-reverse brake is slipping.
In this case, perform hydraulic test to locate cause
of slippage.
Stall Speed Below Specification in “D” and “R”
If stall speed is lower than specification, insufficient
engine output or faulty torque converter is sus-
pected. Check for engine misfiring, ignition timing,
valve clearance etc. If these are good, torque
converter is faulty.
Symptom
Selector lever operation isstiff
Probable causeIncorrect adjustment of sleeve
Incorrect adjustment of control cable
Excessive wear of detent plate
Worn contact surfaces of pushbutton and sleeveRemedyAdjust
Replace
Starter motor does notoperate with the selector
lever in the “N” or
“P”position
Will not shift to
4-speedMalfunction in inhibitor switch
Malfunction of starter relay
Incorrect adjustment of control cableMalfunction of OD switch
Replace
Adjust
Replace
HEATERS AND AIR CONDITIONING - Service Adjustment Procedures 249*I3
--Air-therm0
sensor
Air inlet
sensor
E>aporator(3)
Set the gauge manifold in place and check whether or not
the pressure at the high-pressure side has become the
dual-pressure switch activation pressure.
(4) Replace the switch if, under ordinary conditions, there is no
continuity.Caution
The condition can be considered to be satisfactory if
there is continuity.
Never increase the pressure in a deliberate attempt to
obtain an abnormally high temperature, because to do
so risks blowing the compressor relief valve.AIR-THERM0 SENSOR AND AIR-INLET SENSOR
If frost forms on the surfaces of the evaporator fins, the cause
might be a malfunction of
air-therm0 sensor.
The temperature of the air-flowing from the evaporator’s outlet
is sensed by the thermistor, and the signals conveying this dataare input to the air conditioner control unit, thus switching the
compressor’s clutch ON or OFF.
This functions when the evaporator’s air-flow is low, or the
evaporator’s fins are clogged by dust, etc., or when the amountof refrigerant is insufficient.
These sensors detect the temperature within the passenger
compartment and the temperature at the cooling unit inlet,
thus causing changes of the resistance value, and this data is
provided to the air conditioner control unit as input.
How to Test the Therm0 Sensor and Air-Inlet Sensor
(1) Disconnect the sensor’s connector at the evaporator case,
and by using an ohmmeter, measure the resistance. The
resistance is normal if it is within the range shown in the
figure at the left; if the resistance is not normal, replace.
(2) If the sensor is normal, there is a malfunction of the air
conditioner control unit, and it should be replaced.
Standard value:
Passenger compartment temperature sensor resist-
ance value:
0°C (32°F)4,852+243 (S-2)
15°C (59°F)2,341+234 (S-2)
25°C (77°F)1,500+150 (52)
ENGINE COOLANT TEMPERATURE SWITCH
<2.0L DOHC Engine>
The engine coolant temperature switch is connected in series
with the compressor magnetic clutch power relay.
It disengages the compressor when the temperature of
engine coolant rises above
115°C (239°F).This is designed to prevent engine overheating when cooling
air is not sufficient for the condenser and radiator. If the enginecoolant temperature switch operates to disengage the com-
pressor, check for the condenser and radiator surface condi-
tions, belt tension and engine coolant level and correct, if
necessary.
