Inspection Procedure 10: Shift shock and slipping
COMMENTS ON TROUBLE SYMPTOM
If shift shock when driving are due to upshifting or downshifting and the transmission speed become higher than the engine speed, the cause is probably abnormal line pressure or a malfunction of a solenoid valve, oil pump, valve body or of a brake or clutch.
PROBABLE CAUSES
- Malfunction of each solenoid valve
- Abnormal line pressure
- Malfunction of valve body
- Malfunction of oil pump
- Malfunction of each brake or each clutch
- Malfunction of the engine-A/T-ECU
|
|
STEP 1. M.U.T.-III actuator test
|
|
|
- Item 01: Low-reverse solenoid valve
- Item 02: Underdrive solenoid valve
- Item 03: Second solenoid valve
- Item 04: Overdrive solenoid valve
|
|
|
OK: Operating sound can be heard.
|
|
|
Q.
Is the check result normal?
|
|
|
 Go to Step 2.
|
|
|
|
|
|
 Replace the defective solenoid valve.
|
|
|
|
|
|
STEP 2. M.U.T.-III data list
|
|
|
- Item 63: Shift position (Refer to data list reference table
 ).
- Item 31, 32, 33, 34: Each solenoid valve duty ratio (Refer to data list reference table ).
|
|
|
Q.
Is the check result normal?
|
|
|
Go to Step 3.
|
|
|
|
|
|
Replace the engine-A/T-ECU.
|
|
|
|
|
|
STEP 3. Hydraulic pressure test
|
|
|
Check all hydraulic pressures within the standard value.
|
|
|
OK: Refer to .
|
|
|
Q.
Is the check result normal?
|
|
|
Go to Step 6.
|
|
|
|
|
|
Go to Step 4.
|
|
|
|
|
|
STEP 4. Line pressure adjustment
|
|
|
(1)Adjust the line pressure (Refer to ).
|
|
|
(2)Test drive the vehicle.
|
|
|
(3)Verify that the condition described by the customer exists.
|
|
|
Q.
Does a malfunction take place again?
|
|
|
Go to Step 5.
|
|
|
|
|
|
The inspection is complete.
|
|
|
|
|
|
STEP 5. Valve body disassembly clean and assembly
|
|
|
(1)Check the bolts for looseness and the O-ring, solenoid valves, springs and valve body for damage.
Replace the valve body assembly if the damages are thought to be irreparable.
|
|
|
(2)Test drive the vehicle.
|
|
|
(3)Verify that the condition described by the customer exists.
|
|
|
Q.
Does a malfunction take place again?
|
|
|
Check the oil pump for incorrect installation, damage and etc., and replace the oil pump assembly if necessary (The oil pump cannot be disassembled).
|
|
|
|
|
|
The inspection is complete.
|
|
|
|
|
|
STEP 6. Each clutch and brake check
|
|
|
Check the facing for seizure and the piston seal ring for damage and interference with the retainer.
|
|
|
Q.
Is the check result normal?
|
|
|
The inspection is complete.
|
|
|
|
|
|
Repair or replace each clutch and brake.
|
|
|
|