Inspection Procedure 8: Shift Shock when Shifting from N to D, N to R and Long Delay


COMMENTS ON TROUBLE SYMPTOM



PROBABLE CAUSES



  • Abnormal line pressure
  • Malfunction of accelerator pedal position sensor
  • Malfunction of oil pump
  • Malfunction of valve body
  • Malfunction of the engine-A/T-ECU

DIAGNOSIS PROCEDURE

STEP 1. Hydraulic pressure test
Measure the hydraulic pressure of each element when the transmission is in 1st gear, 2nd gear or reverse gear.
OK: Refer to .

Q. Is the check result normal?
Go to Step 3.
Go to Step 2.

STEP 2. 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 3.
The inspection is complete.

STEP 3. Check when shift shock occurs.

Q. Does the shift shock occur when the vehicle starts moving?
Go to Step 4.
Check the oil pump for incorrect installation, damage and etc., and replace the oil pump assembly if necessary (The oil pump cannot be disassembled.)

STEP 4. Check when shift shock occurs.

Q. Does the shift shock always occur?
Go to Step 7.
Go to Step 5.

STEP 5. M.U.T.-III data list
Item 2: Accelerator pedal position sensor (Refer to data list reference table ).

Q. Is the check result normal?
Go to Step 6.
Check the accelerator pedal position sensor system (Refer to GROUP 13A - Troubleshooting, Inspection Chart For Diagnosis Code ).

STEP 6. Engine-A/T-ECU replacement
(1)Replace the engine-A/T-ECU.
(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 7.
The inspection is complete.

STEP 7. Valve body disassembly clean and assembly
(1)Check the bolts for looseness and the O-ring, solenoid valve 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?
The inspection is complete.
Replace the valve body assembly if the damages are thought to be irreparable.