Inspection Procedure 14: Gear shift does not occur with 4th <=> 5th


COMMENTS ON TROUBLE SYMPTOM



PROBABLE CAUSES



  • Malfunction of inhibitor switch system
  • Malfunction of input shaft speed sensor system
  • Malfunction of shift solenoid SR system
  • Malfunction of valve body (linear solenoid No.1, linear solenoid No.2)
  • Malfunction of the A/T-ECU
  • A/T internal error (clutch C1, brake B1, etc.)

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III data list
Item 34: Inhibitor switch (Refer to data list reference table ).

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

STEP 2. Inhibitor switch continuity check
Refer to .

Q. Is the check result normal?
Go to Step 3.
Replace the inhibitor switch.

STEP 3. M.U.T.-III actuator test
Item 20: Shift solenoid SR
OK: Operating sound can be heard.

Q. Is the check result normal?
Go to Step 4.
Repair the shift solenoid SR system.

STEP 4. M.U.T.-III data list
Item 5: Input shaft speed sensor (Refer to data list reference table ).

Q. Is the check result normal?
Go to Step 5.
Repair the input shaft speed sensor system.

STEP 5. Retest the system
If the trouble symptom is not solved, replace the valve body. Then, check the trouble symptom again.

Q. Is the trouble symptom reproduced?
Go to Step 6.
This diagnosis is complete.

STEP 6. A/T-ECU replacement
(1)Replace the A/T-ECU.
(2)Test drive the vehicle.
(3)Verify that the condition described by the customer exists.

Q. Is the trouble symptom reproduced?
Check the clutches and brakes for damage, and replace if necessary. (It is highly possible that the clutch C1 and brake B1 that operate at shift change between 4th and 5th are damaged.)
This diagnosis is complete.