NO.17 EXCESSIVE SHIFT SHOCK FROM N TO D OR N TO R POSITION [AY6A-EL, AY6AX-EL]

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17 | Excessive shift shock from N to D or N to R position
DESCRIPTION | • Strong shock felt when shifting from N to D or N to R position at idle.
POSSIBLE CAUSE | • Shift shock may worsen when the fail-safe is operating. If no DTC is output, the shift shock may worsen due to poor operation of the control valve body or sticking of the clutch. ― Clutch burnt (N→D: C1 clutch, N→R: C3 clutch or B2 brake) • Line pressure low • Incorrect accelerator opening signal • TFT sensor malfunction • Sensor ground malfunction • Shift solenoid B malfunction • Shift solenoid C malfunction • Shift solenoid E malfunction • Line pressure control solenoid malfunction • Control valve body malfunction • Not within ATF amount ― Poor hydraulic operation (Malfunction in range change) ― Idle speed high ― Poor tightening torque of engine mount, exhaust mount ― Line pressure high ― Garage shift control is not learned • Initial learning did not perform Note • Before following the troubleshooting steps, make sure that the Automatic Transaxle On-Board Diagnostic and Automatic Transaxle Basic Inspection are conducted. (See BASIC INSPECTION [AY6A-EL, AY6AX-EL].)

Diagnostic procedure

STEP | INSPECTION | ACTION
--- | --- | ---
1 | • Does the shift shock occur only when the engine is cold? | Yes | Go to the next step.
No | Go to Step 3.
2 | • Inspect the TFT sensor and related wiring harness: vibration, intermittent open/short circuit. (See TRANSAXLE FLUID TEMPERATURE (TFT) SENSOR INSPECTION [AY6A-EL, AY6AX-EL].) • Is it normal? | Yes | Go to the next step.
No | Repair or replace part if necessary.
3 | • Perform the initial learning procedure. (See Initial Learning.) • Does symptom eliminate? | Yes | Troubleshooting is completed.
No | Go to the next step.
4 | • Is the line pressure normal? (See LINE PRESSURE CONTROL SOLENOID INSPECTION [AY6A-EL, AY6AX-EL].) | Yes | Go to the next step.
No | Repair or replace any malfunctioning parts according to the inspection results.
5 | • Is stall speed normal? (See MECHANICAL SYSTEM TEST [AY6A-EL, AY6AX-EL].) | Yes | Go to the next step.
No | Repair or replace any malfunctioning parts according to the inspection results.
6 | • Stop the engine. • Inspect following solenoids. ― Line pressure control solenoid (See LINE PRESSURE CONTROL SOLENOID INSPECTION [AY6A-EL, AY6AX-EL].) ― Shift solenoid B (See SHIFT SOLENOID B INSPECTION [AY6A-EL, AY6AX-EL].) ― Shift solenoid C (See SHIFT SOLENOID C INSPECTION [AY6A-EL, AY6AX-EL].) ― Shift solenoid E (See SHIFT SOLENOID E INSPECTION [AY6A-EL, AY6AX-EL].) • Are they normal? | Yes | Go to the next step.
No | Replace the control valve body. (See CONTROL VALVE BODY REMOVAL/INSTALLATION [AY6A-EL, AY6AX-EL].)
7 | • Inspect the ATF condition. • Are a metal specks found? | Yes | If large amount of metal specks are found, replace the transaxle. (See AUTOMATIC TRANSAXLE REMOVAL/INSTALLATION [AY6A-EL, AY6AX-EL].) If a large amount of metal specks are not found, replace the control valve body. (See CONTROL VALVE BODY REMOVAL/INSTALLATION [AY6A-EL, AY6AX-EL].)
No | Perform the “AUTOMATIC TRANSAXLE FLUID (ATF) LEVEL ADJUSTMENT” procedure. (See AUTOMATIC TRANSAXLE FLUID (ATF) LEVEL ADJUSTMENT [AY6A-EL, AY6AX-EL].)
8 | • Verify test results. ― If normal, return to the diagnostic index to service any additional symptoms. ― If malfunction remains, inspect the related Service Bulletins and/or On-line Repair Information and perform repair or diagnosis. • If the vehicle is repaired, troubleshooting completed. • If the vehicle is not repaired or additional diagnostic information is not available, replace the TCM.

Initial Learning

  Warning
  • When performing initial learning, be aware of other vehicles, people, and other impediments in order to avoid an accident.

  Note
  • While self-learning control gradually reduces shock during normal driving, initial learning is performed to initially learn a certain amount of driving conditions.

1. Warm-up

  • Increase the ATF temperature by leaving the vehicle idling or performing city driving. Verify that the ATF temperature is between 66—110 °C {151—230 °F}. If the ATF temperature is outside this range, work to bring it inside the range.

  Caution
  • Do not raise the ATF temperature by stalling the engine.

  Note
  • If the ATF temperature is not between 66—110 °C {151—230 °F}, initial learning cannot be performed.
  Before learning, inspect for variable shift shock.

2. Garage shift learning

  • With the vehicle standing still, depress the brake pedal and keep the selector lever in N position for 3 s. Then, shift the selector lever from the N position into D position, and maintain in this condition for 3 s. Repeat this procedure 5 times. Then repeat it 5 times in the same way for R position.

3. Gear shift control learning

  • In D position, with the accelerator opening between 25—30%, drive until you reach 6th gear and a vehicle speed of 80 km/h {50 mph} or higher. Then, release the accelerator pedal and coast, and bring the vehicle to a stop in at least 60 s. Repeat this procedure 10 times.

4. Inspect learning results

  • Verify that variable speed shock and shift shock have decreased compared to the conditions before learning.