Inspection Procedure 24: Shock is significant at upshift

COMMENTS ON TROUBLE SYMPTOM

During driving, if a strong shock occurs at upshift, 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), A/T fluid temperature sensor 1 system, 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)
Malfunction of A/T fluid temperature sensor 1 system
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. M.U.T.-III data list

Item 6: A/T fluid temperature sensor 1 (Refer to data list reference table

Q. Is the check result normal?

	Go to Step 3.

	Repair the A/T fluid temperature sensor 1 system.

STEP 3. Mounting check

Check the engine mounting and transmission mounting insulator for damage and any faults.

Q. Is the check result normal?

	Go to Step 4.

	Repair or replace the engine mounting and transmission mounting insulator.

STEP 4. A/T fluid change

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

Q. Is the trouble symptom reproduced?

	Go to Step 5.

	This diagnosis is complete.

STEP 5. Valve body replacement

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

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.