Inspection Procedure 8: Engine stall at shifting (N → D, N → R)


COMMENTS ON TROUBLE SYMPTOM


If an engine stall occurs when the selector lever is shifted from N to D or to R, the cause is probably an abnormal line pressure or a malfunction of the torque converter, A/T fluid cooler pipe, engine system, valve body, or oil pump.

PROBABLE CAUSES



DIAGNOSIS PROCEDURE

STEP 1. Hydraulic pressure test
Measure the line pressure (Refer to ).
OK: Refer to .

Q. Is the check result normal?
Go to Step 2.
Go to Step 3.

STEP 2. 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 3. A/T fluid cooler pipe check
Check the installation status, damage, bend, clogging, and others of A/T fluid cooler pipe.

Q. Is the check result normal?
Go to Step 4.
Repair or replace the A/T fluid cooler pipe system.

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?
Go to Step 6.
This diagnosis is complete.

STEP 6. A/T internal check
After checking the oil pump for damage, check each clutch and brake for any damage, and replace if necessary.

Q. Is the trouble symptom reproduced?
Go to Step 7.
This diagnosis is complete.

STEP 7. Engine system check
Refer to GROUP 13B - Troubleshooting <6B3>.
Refer to GROUP 13C - Troubleshooting <4N1>.

Q. Is the check result normal?
This diagnosis is complete.
Repair the engine system.