Toyota Celica 2005 Repair Manual page 884

9. PROBLEM SYMPTOM CONFIRMATION
Taking into consideration the results of the customer problem analysis, try to reproduce the symptoms of the
trouble. If the problem is that the transaxle does not up−shift, down−shift, or the shift point is too high or too
low, conduct the following road test to confirm the automatic shift schedule and simulate the problem symp-
toms.
10. ROAD TEST
NOTICE:
Perform the test at normal operating ATF temperature 50 to 80 °C (122 to 176 °F).
(a) D position test
Shift into the D position and fully depress the accelerator pedal and check the following points.
(1) Check up−shift operation.
Check that 1 → 2, 2 → 3 and 3 → O/D up−shifts take place, and that the shift points conform to
the automatic shift schedule (See page SS−42).
HINT:
O/D Gear Up−shift Prohibition Control (1. Coolant temp. is 60 °C (140 °F) or less. 2. If there is a 10
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km/h (6 mph) difference between the set cruise control speed and vehicle speed.)
O/D Gear Lock−up Prohibition Control (1. Brake pedal is depressed. 2. Coolant temp. is 60 °C (140
S
°F) or less.)
(2) Check for shift shock and slip.
Check for shock and slip at the 1 → 2, 2 → 3 and 3 → O/D up−shifts.
(3) Check for abnormal noises and vibration.
Drive in the D position lock−up or O/D gear and check for abnormal noises and vibration.
HINT:
The check for the cause of abnormal noises and vibration must be done very thoroughly as it could also be
due to loss of balance in the differential, torque converter clutch, etc.
(4) Check kick−down operation.
While driving in the D position, 2nd, 3rd and O/D gears, check that the possible kick−down ve-
hicle speed limits for 2 → 1, 3 → 2 and O/D → 3 kick−downs conform to those indicated on the
automatic shift schedule (See page SS−42).
(5) Check abnormal shock and slip at kick−down.
(6) Check the lock−up mechanism.
Drive in D position, O/D gear, at a steady speed (lock−up ON) of about 60 km/h (37 mph).
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Lightly depress the accelerator pedal and check that the engine speed does not change
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abruptly.
If there is a big jump in engine speed, there is no lock−up.
(b) M position test
Shift to the M position, depress the accelerator pedal and check the following points.
Shift operations.
Pressing the transmission shift switch to "Up" or " Down" makes the transmission up−shifted or down−
shifted respectively.
Without pressing the switch, it is not automatically shifted to either up or down.
When a vehicle is stopped, it is automatically down−shifted to 1st gear.
HINT:
Manual shift prohibition control (1. When the ATF temperature is low. 2. When down−shifting causes engine
overrun. 3. When down−shifting is required continuously, down−shifting to 1st gear may not be performed.
4. When the ATF temp. is high, up−shifting to O/D is not performed.)
2005 CELICA (RM1131U)
DIAGNOSTICS − AUTOMATIC TRANSAXLE (U240E)
883
DI−685