MECHANICAL SYSTEM TEST [FN4A-EL]

id0517a1802100

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 [ZJ, ZY].)

3. Inspect the engine oil. (See ENGINE OIL LEVEL INSPECTION [ZJ, ZY].)

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

5. Inspect the idle speed and ignition timing in P position. (See IDLE SPEED INSPECTION [ZJ, ZY (WITH WU-TWC)].) (See IDLE SPEED INSPECTION [ZJ, ZY (WITHOUT WU-TWC)].) (See IGNITION TIMING INSPECTION [ZJ, ZY].)

6. Bring 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 H019 002 and, 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).

am2zzw00005214

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 engine speed for the D range.

6. Read the line pressure at idle engine 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 D range position.

  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 11 and 12 within 5 seconds 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 N position and let the engine idle 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.

Line pressure

Position/Range | Specification (kPa {kgf/cm2, psi})
--- | ---
D, S, L (Includes each HOLD mode) | Idle | 330—470 {3.4—4.7, 48—68}
Stall | 1,030—1,190 {10.5—12.1, 150—172}
R | Idle | 490—710 {5.0—7.2, 71—102}
Stall | 1,700—2,050 {17.4—20.9, 247—297}

  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—99 kgf·cm, 43—85 in·lbf}

Evaluation of line pressure test

Condition | Possible cause
--- | ---
Low pressure in all position/ranges | Worn oil pump Oil leaking from oil pump, control valve body, and/or transaxle case Pressure regulator valve sticking Pressure control solenoid malfunction Pressure modulator valve sticking Solenoid reducing valve sticking
Low pressure in D, S, L ranges | Oil leaking from hydraulic circuit of forward clutch
Low pressure in D (HOLD), S (HOLD) ranges | Oil leaking from hydraulic circuit of 2-4 brake band
Low pressure in L (HOLD) range, R position | Oil leaking from hydraulic circuit of low and reverse brake
Low pressure in R position | Oil leaking from hydraulic circuit of reverse clutch
High pressure in all position/ranges | Pressure control solenoid malfunction Pressure regulator valve sticking Pressure modulator valve sticking Pressure reducing valve sticking

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 seconds while the brake pedal is pressed, the transaxle could be damaged. Therefore, perform Steps 5 and 6 within 5 seconds 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 N position and let the engine idle 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 | Specification (rpm)
--- | ---
D, S, L (Includes each HOLD mode) | 2,000—2,600
R

Evaluation of stall test

Condition | Possible cause
--- | ---
Above specification | In all position/ranges | Insufficient line pressure | Worm oil pump
Oil leaking from oil pump, control valve, and/or transaxle case
Pressure regulator valve sticking
Pressure control solenoid malfunction
Pressure modulator valve sticking
In D, S, L ranges | Forward clutch slippage
In D range | One-way clutch malfunction
In D, D (HOLD), S (HOLD) ranges | 2-4 brake band slippage One-way clutch malfunction
In D, L (HOLD) ranges | Low and reverse brake slippage One-way clutch malfunction
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 (HOLD) range: Reverse clutch • Engine braking not felt in L (HOLD) 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 it takes from shifting until shock is felt when shifting the selector lever from 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