Inspection Procedure 7: N → R time lag

COMMENTS ON TROUBLE SYMPTOM

If a time lag of 2 second or more occurs when the selector lever is shifted from N to R, the cause is probably an abnormal line pressure or a malfunction of the solenoid valve harness system, stop lamp switch system, valve body, or oil pump.

PROBABLE CAUSES

Insufficient A/T fluid amount, immixing of water or unspecified A/T fluid
Malfunction of stop lamp switch system
Malfunction of solenoid valve harness system
Malfunction of valve body
Malfunction of the A/T-ECU
A/T internal error (oil pump, clutch C3, brake B1/B4, one-way clutch F1, etc.)

DIAGNOSIS PROCEDURE

STEP 1. A/T fluid check

Check the A/T fluid for amount and condition (not severely contaminated), and fill or replace the A/T fluid if necessary. Then, check the trouble symptom again.

Q. Is the trouble symptom reproduced?

	Go to Step 2.

	This diagnosis is complete.

STEP 2. Hydraulic pressure test

Measure the line pressure (Refer to

note

If a time lag occurs, the line pressure may be lower than the standard value.

OK: Refer to .

Q. Is the check result normal?

	Go to Step 3.

	Go to Step 4.

STEP 3. Stop lamp switch system check

The stop lamps should illuminate when the brake pedal is depressed, and extinguish when released.

Q. Is the check result normal?

	Go to Step 6.

	Refer to stop lamp switch system (Refer to GROUP 54A - ETACS - Troubleshooting, Input Signal Procedures).

STEP 4. Retest the system

If the trouble symptom occurs again, check and replace the solenoid harness. Then, check the trouble symptom again.

Q. Is the trouble symptom reproduced?

	Go to Step 5.

	This diagnosis is complete.

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. 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. (It is highly possible that the clutch C3, brake B1/B4, and one-way clutch F1 that engage in reverse gear are damaged.)

	This diagnosis is complete.