Inspection Procedure 20: Shift point fault

COMMENTS ON TROUBLE SYMPTOM

If the shift point is deviated, the cause is probably a malfunction of the engine system, line pressure control solenoid system, input shaft speed sensor system, output shaft speed sensor system, or A/T fluid temperature sensor 1 system.

PROBABLE CAUSES

Malfunction of engine system
Malfunction of valve body (line pressure control solenoid)
Malfunction of input shaft speed sensor system
Malfunction of output shaft speed sensor system
Malfunction of A/T fluid temperature sensor 1 system
Malfunction of the A/T-ECU

DIAGNOSIS PROCEDURE

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

Item 2: Accelerator pedal position sensor (Refer to data list reference table

Q. Is the check result normal?

	Go to Step 2.

	Check the engine system.

STEP 2. M.U.T.-III data list

Item 4: Input shaft speed sensor (Refer to data list reference table

Q. Is the check result normal?

	Go to Step 3.

	Repair the input shaft speed sensor system.

STEP 3. M.U.T.-III data list

Item 5: Output shaft speed sensor (Refer to data list reference table

Q. Is the check result normal?

	Go to Step 4.

	Repair the output shaft speed sensor system.

STEP 4. 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 5.

	Repair the A/T fluid temperature sensor 1 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. Retest the system

Q. Is the trouble symptom reproduced?

	Replace the A/T-ECU.

	This diagnosis is complete.