ROAD TEST
1. PROBLEM SYMPTOM CONFIRMATION
(a) Based on the result of the customer problem analysis, try to reproduce the symptoms. If the problem is that the transmission does not shift up or shift down, or that the shift point is too high or too low, conduct the following road test while referring to the automatic shift schedule and reproduce the problem symptoms.
2. ROAD TEST
HINT:
The ECM controls the transmission based on the vehicle condition according to the table below.
Automatic Transmission Control
Vehicle Condition |
Automatic Transmission Control Performed |
---|---|
|
Lock-up prohibition control |
|
Acceleration flex lock-up prohibition control |
ATF temperature is below 20°C (68°F), or is 110°C (230°F) or higher |
Deceleration flex lock-up prohibition control |
ATF temperature is 130°C (266°F) or higher |
Lock-up schedule is changed |
|
Shift change prohibition control |
Engine coolant temperature is below 55°C (131°F) and the vehicle speed is less than 45 km/h (28 mph) |
4th Gear Up-shift Prohibition Control |
Engine coolant temperature is below 55°C (131°F) and the vehicle speed is less than 51 km/h (32 mph) |
5th Gear Up-shift Prohibition Control |
(a) D position test
(1) Check up-shift operation.
Check the 1 → 2, 2 → 3, 3 → 4 and 4 → 5 up-shifts.
(2) Check for shift shock and slippage.
Check for shock and slippage at the 1 → 2, 2 → 3, 3 → 4 and 4 → 5 up-shifts.
(3) Check for abnormal noise and vibration.
Check for abnormal noise and vibration when up-shifting from 1 → 2, 2 → 3, 3 → 4 and 4 → 5 while driving with the shift lever in D, and also check while driving in the lock-up condition.
HINT:
The check for the cause of abnormal noise and vibration must be done thoroughly as it could also be due to loss of balance in the differential, torque converter, etc.
(4) Check kick-down operation.
Check that the 2 → 1, 3 → 2, 4 → 3 and 5 → 4 kick-downs take place when accelerating with the shift lever in D.
(5) Check for abnormal shock and slippage at each kick-down.
(6) Check the lock-up mechanism.
HINT:
If there is a sudden increase in engine speed, there is no lock-up.
(b) S position test
(1) Check shift operation.
HINT:
Manual shifting (S position) is prohibited under either of the following conditions:
(c) R position test
Move the shift lever to R and lightly depress the accelerator pedal. Check that the vehicle moves backward without any abnormal noise or vibration.
CAUTION:
Before conducting this test, make sure that the test area is free from people and obstructions.
(d) P position test
Stop the vehicle on an incline (more than 5°). Then move the shift lever to P and release the parking brake. Check that the parking lock pawl holds the vehicle in place.
Lost Communication with ECM (C1437)
DESCRIPTION
The skid control ECU receives signals from the ECM via the CAN communication
system.
DTC Code
DTC Detection Condition
Trouble Area
C1437
When the IG1 terminal voltage is 10 V or highe ...
Disassembly
DISASSEMBLY
CAUTION / NOTICE / HINT
HINT:
Use the same procedure for both the RH and LH sides.
The procedure listed below is for the LH side.
PROCEDURE
1. DISCONNECT CABLE FROM NEGATIVE BATTERY TERMINAL
NOTICE:
When disconnecting the c ...