Inspection Procedure 22: Shock is significant when driving with accelerator fully closed


COMMENTS ON TROUBLE SYMPTOM


During driving, if a strong shock occurs when the foot is lifted from the accelerator pedal, the cause is probably an immixing of A/T fluid other than the specified one, a malfunction of the shift solenoid No.1 system, shift solenoid No.2 system, shift solenoid SR system, line pressure control solenoid system, clutch control solenoid No.1 system, clutch control solenoid No.2 system, mounting (engine mounting and transmission mounting insulator), or valve body.
note As a cause of shock, a battery voltage abnormality, engine system malfunction, driveshaft malfunction (damage, wear, looseness, large deflection), or suspension malfunction (looseness) is suspected. However, in this item, it shall be presupposed that there is no abnormality to the above.

PROBABLE CAUSES



DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III actuator test

  • Item 1: Shift solenoid No.1
  • Item 2: Shift solenoid No.2
  • Item 3: Shift solenoid SR
OK: Operating sound can be heard.

Q. Is the check result normal?
Go to Step 2.
Repair the shift solenoid No.1 system, shift solenoid No.2 system, and shift solenoid SR system.

STEP 2. Mounting check
Check the engine mounting and transmission mounting insulator for damage and any faults.

Q. Is the check result normal?
Go to Step 3.
Repair or replace the engine mounting and transmission mounting insulator.

STEP 3. A/T fluid change
Replace the A/T fluid. Then, check the trouble symptom again.

Q. Is the trouble symptom reproduced?
Go to Step 4.
This diagnosis is complete.

STEP 4. Valve body replacement
Replace the valve body. Then, check the trouble symptom again.

Q. Is the trouble symptom reproduced?
Go to Step 5.
This diagnosis is complete.

STEP 5. A/T-ECU replacement
Replace the A/T-ECU. Then, check the trouble symptom again.

Q. Is the trouble symptom reproduced?
Check the clutches and brakes for damage, and replace if necessary.
This diagnosis is complete.