Inspection Procedure 9: Engine stall at deceleration

COMMENTS ON TROUBLE SYMPTOM

If an engine stall occurs at deceleration, the cause is probably an abnormal line pressure or a malfunction of the engine system, torque converter, valve body, or oil pump.

PROBABLE CAUSES

Malfunction of engine system
Malfunction of torque converter
Malfunction of valve body
Malfunction of the A/T-ECU
A/T internal error (oil pump, clutches, brakes, etc.)

DIAGNOSIS PROCEDURE

STEP 1. Engine system check

Refer to GROUP 13E - Troubleshooting

Q. Is the check result normal?

	Go to Step 2.

	Repair the engine system.

STEP 2. Hydraulic pressure test

Measure the line pressure (Refer to

OK: Refer to .

Q. Is the check result normal?

	Go to Step 3.

	Go to Step 4.

STEP 3. Torque converter stall test

Carry out the torque converter stall test (Refer to

), and replace the torque converter if the result is out of the standard value. Then, check the trouble symptom again.

Q. Is the trouble symptom reproduced?

	Go to Step 5.

	This diagnosis is complete.

STEP 4. 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 5.

	This diagnosis is complete.

STEP 5. 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?

	After checking the oil pump for damage, check each clutch and brake for any damage, and replace if necessary.

	This diagnosis is complete.