MECHANICAL SYSTEM TEST [FN4A-EL]


BME051701030201

Mechanical System Test Preparation

1. Engage the parking brake and use wheel chocks at the front and rear of the wheels.

2. Inspect the engine coolant. (See ENGINE COOLANT LEVEL INSPECTION.)

3. Inspect the engine oil. (See ENGINE OIL LEVEL INSPECTION.)

4. Inspect the ATF levels. (See AUTOMATIC TRANSAXLE FLUID (ATF) INSPECTION [FN4A-EL].)

5. Inspect the idle speed and ignition timing in the P position.

(See IDLE SPEED INSPECTION [L3].) (See IGNITION TIMING INSPECTION [L3].)

6. Warm up the engine and transaxle to normal operating temperature.

Line Pressure Test

1. Perform mechanical system test preparation. (See Mechanical System Test Preparation.)

Warning
• Removing the square-head plug when the ATF is hot can be dangerous. Hot ATF can come out of the opening and badly burn you. Before removing the square-head plug, allow the ATF to cool.

2. Connect the SSTs (49 0378 400C) to the line pressure inspection port, then replace the gauge of the SST (49 0378 400C) with the SST (49 B019 901B).

3. Start the engine, then warm up the automatic transaxle.

4. Shift the selector lever to D range.

5. Read the line pressure at idle speed for the D range.

6. Read the line pressure at idle speed for the D (HOLD), S, S (HOLD), L, L (HOLD) ranges and R positions in the same manner as in Steps 4-5.

7. Stop the engine, then replace the SST (49 B019 901B) with the gauge of the SST (49 0378 400C).

8. Start the engine.

9. Firmly depress the brake pedal with the left foot.

10. Shift the selector lever to the D range position.

Caution
• If the accelerator pedal is depressed for more than 5 s while the brake pedal is depressed, the transaxle could be damaged. Therefore, perform Steps 11 and 12 within 5 s each.

11. Gradually depress the accelerator pedal with the right foot.

12. When the engine speed no longer increases, quickly read the line pressure and release the accelerator pedal.

13. Shift the selector lever to the N position and idle the engine for 1 min or more to cool the ATF.

14. Read the line pressure at the engine stall speed for the D, D (HOLD), S, S (HOLD), L, L (HOLD) ranges and R position in the same manner as in Steps 9-13.

Specified line pressure

Position/Range

Line pressure (kPa {kgf/cm2, psi})

L3

D, S, L*
idle
330-470 {3.4-4.7, 49-66}
Stall
1,160-1,320 {11.9-13.4, 170-190}
R
idle
490-710 {5.0-7.2, 72-102}
Stall
1,630-1,850 {16.7-18.8, 238-267}

* :
Includes each HOLD mode.
Warning
• Removing the square-head plug when the ATF is hot can be dangerous. Hot ATF can come out of the opening and badly burn you. Before removing the square-head plug, allow the ATF to cool.

15. Remove the SSTs.

16. Install a new square head plug in the inspection port.

Tightening torque
4.8-9.8 N·m {49-100 kgf·cm, 43-86 in·lbf}

Evaluation of line pressure test

Line pressure

Possible cause

Low pressure in all ranges
Worn oil pump
Oil leaking from oil pump, control valve body, and/or transaxle case
Stuck pressure regulator valve
Pressure control solenoid malfunction
Stuck pressure modulator valve
Stuck solenoid reducing valve
Low pressure in D and S only
Oil leakage from hydraulic circuit of forward clutch
Low pressure in L and R only
Oil leakage from hydraulic circuit of low and reverse brake
Low pressure in R only
Oil leakage from hydraulic circuit of reverse clutch
High pressure in all ranges
Pressure control solenoid malfunction
Stuck pressure regulator valve
Stuck pressure modulator valve
Stuck pressure reducing valve

Stall Test

1. Perform mechanical system test preparation. (See Mechanical System Test Preparation.)

2. Start the engine.

3. Firmly depress the brake pedal with the left foot.

4. Shift the selector lever to D range.

Caution
• If the accelerator pedal is pressed for longer than 5 s while the brake pedal is pressed, the transaxle could be damaged. Therefore, perform Steps 5 and 6 within 5 s of each other.

5. Gently depress the accelerator pedal with the right foot.

6. When the engine speed no longer increases, quickly read the speed and release the accelerator pedal. When the engine speed no longer increases, quickly read the speed and release the accelerator pedal.

7. Shift the selector lever to the N position and idle the engine for 1 min or more to cool the ATF.

8. Perform a stall test of D (HOLD), S, S (HOLD), L, L (HOLD) and R range positions in the same manner as in Steps 3-7.

9. Turn the ignition switch off.

Engine stall speed

Position/Range

Engine stall speed (rpm)

L3

D, S, L*
2,100-2,600
R

* :
Includes each HOLD mode

Evaluation of stall test

Condition

Possible cause

Above specification
In all forward ranges and R position
Insufficient line pressure
Worn oil pump
Oil leakage from oil pump, control valve, and/or transaxle case
Stuck pressure regulator valve
Pressure control solenoid malfunction
Stuck pressure modulator valve
In forward ranges
Forward clutch slippage
One-way clutch 1 slippage
In D ranges
One-way clutch 2 slippage
In S ranges
2-4 brake band slippage
In L range and R position
Low and reverse brake slippage
In R position
Low and reverse brake slippage
Reverse clutch slipping
Perform road test to determine whether problem is low and reverse brake or reverse clutch
• Engine braking felt in L range: Reverse clutch
• Engine braking not felt in L range: Low and reverse brake
Below specification
Engine out of tune
One-way clutch slipping within torque converter

Time Lag Test

1. Perform mechanical system test preparation. (See Mechanical System Test Preparation.)

2. Use a stopwatch to measure the time taken until the shock is felt after shifting the selector lever from the N position to D range (non-HOLD mode). Take three measurements for each test and take the average from the results using the following formula.

Formula:
Average time lag = (Time 1 + Time 2 + Time 3) / 3

3. Perform the test for the following shifts in the same manner Step 2.

• N position → D range (HOLD mode)
• N position → R position
Time lag
N position → D range... 0.4-0.7 s
N position → R position... 0.4-0.7 s

Evaluation of time lag test

Condition

Possible Cause

N → D shift
More than specification
Insufficient line pressure
Forward clutch slipping
Oil leaking from forward clutch fluid circuit
Shift solenoid A not operating properly
Less than specification
Forward accumulator not operating properly
Shift solenoid A not operating properly
Excessive line pressure
N → D (HOLD) shift
More than specification
Insufficient line pressure
Forward clutch slipping
Shift solenoid A not operating properly
Less than specification
Forward accumulator not operating properly
Shift solenoid A not operating properly
Excessive line pressure
N → R shift
More than specification
Insufficient line pressure
Low and reverse brake slipping
Reverse clutch slipping
Shift solenoid B not operating properly
Less than specification
Servo apply accumulator not operating properly
Shift solenoid B not operating properly
Excessive line pressure