Inspection Procedure 25: 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 pressure control solenoid (SL1, SL2, SL3, SL4, SL5) system, line pressure control solenoid (SLT) 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

Malfunction of pressure control solenoid (SL1, SL2, SL3, SL4, SL5) system
Malfunction of line pressure control solenoid (SLT) system
Malfunction of mounting (engine mounting and transmission mounting insulator)
Immixing of A/T fluid other than the specified one
Malfunction of valve body (SL1, SL2, SL3, SL4, SL5, SLT)
Malfunction of the A/T-ECU
A/T internal error (clutches, brakes, etc.)

DIAGNOSIS PROCEDURE

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

Item 4: Line pressure solenoid

Item 5: Linear solenoid 1

Item 6: Linear solenoid 2

Item 7: Linear solenoid 3

Item 8: Linear solenoid 4

Item 9: Linear solenoid 5

OK: Operating sound can be heard.

Q. Is the check result normal?

	Go to Step 2.

	Repair the pressure control solenoid (SL1, SL2, SL3, SL4, SL5) system and line pressure control solenoid (SLT) 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.