-
DIAGNOSTICS
AUTOMATIC TRANSAXLE
DI-161
315
Author:
Date:
2001 SIENNA (RM787U)
(b)
Clear the DTC.
The following operation will erase the DTC and freeze
frame data. Operating an OBD II scan tool (complying
with SAE J1978) or TOYOTA hand-held tester to erase
the codes (See the OBD II scan tool’s instruction book for
operating instructions.).
4.
ROAD TEST
NOTICE:
Perform the test at normal operating ATF temperature 50 - 80
°
C (122 - 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 to see that 1
→
2, 2
→
3 and 3
→
O/D up-shift takes place and that the shift points conform
to the automatic shift schedule (See page
HINT:
O/D Gear Up-shift Prohibition Control (1. Coolant temp. is 60
°
C (140
°
F) or less. 2. If there is a 10
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
°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.
Run at 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 running in the D position, 2nd, 3rd and O/D gears, check to see that the possible kick-down
vehicle speed limits for 2
→
1, 3
→
2 and O/D
→
3 kick-downs conform to those indicated in the
automatic shift schedule (See page
).
(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).
Lightly depress the accelerator pedal and check that the engine speed does not change
abruptly.
If there is a big jump in engine speed, there is no lock-up.
(b)
2 position test:
Shift into the 2 position and fully depress the accelerator pedal and check the following points:
(1)
Check up-shift operation.
Check to see that the 1
→
2 up-shift takes place and that the shift point conforms to the automatic
shift schedule (See page
HINT:
There is no O/D up-shift and lock-up in the 2 position.
(2)
Check engine braking.
While running in the 2 position and 2nd gear, release the accelerator pedal and check the engine
braking effect.
(3)
Check for abnormal noises during acceleration and deceleration, and for shock at up-shift and
down-shift.
