Inspection Procedure 17: Gear shift does not occur with 7th <=> 8th


COMMENTS ON TROUBLE SYMPTOM


When the gear does not shift from 7th to 8th and from 8th to 7th, the cause is probably a malfunction of inhibitor switch system, C3 pressure control solenoid (SL3) system, B1 pressure control solenoid (SL5) system, or valve body.

PROBABLE CAUSES



DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III data list

  • Refer to Data List Reference Table .

    1. Item 24: Inhibitor switch P
    2. Item 25: Inhibitor switch R
    3. Item 26: Inhibitor switch N
    4. Item 27: Inhibitor switch D

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 7: Linear solenoid 3
Item 9: Linear solenoid 5
OK: Operating sound can be heard.

Q. Is the check result normal?
Go to Step 4.
Repair the C3 pressure control solenoid (SL3) system or B1 pressure control solenoid (SL5) system.

STEP 4. Check of inhibitor switch and transmission control cable
Check the installation status of inhibitor switch and transmission control cable.

Q. Is the check result normal?
Go to Step 5.
Adjust the inhibitor switch and the transmission control cable. (Refer to .)

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 C3 and brake B1 that operate at shift change between 7th and 8th are damaged.)
This diagnosis is complete.