NO.17 EXCESSIVE SHIFT SHOCK FROM N TO D OR N TO R POSITION/RANGE [AW6A-EL, AW6AX-EL]SM2445410
NO.17 EXCESSIVE SHIFT SHOCK FROM N TO D OR N TO R POSITION/RANGE [AW6A-EL, AW6AX-EL]

id050310802200

17
Excessive shift shock from N to D or N to R position/range
DESCRIPTION
• Strong shock felt when shifting from N to D or N to R position/range 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 GND malfunction
• Shift solenoid C malfunction
• Shift solenoid E malfunction
• Line pressure control solenoid malfunction
• Coupler component malfunction
• Control valve body malfunction
― 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 [AW6A-EL, AW6AX-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 [AW6A-EL, AW6AX-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 MECHANICAL SYSTEM TEST [AW6A-EL, AW6AX-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 [AW6A-EL, AW6AX-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. (See SOLENOID VALVE INSPECTION [AW6A-EL, AW6AX-EL].)
― Line pressure control solenoid
― Shift solenoid C
― Shift solenoid E
• Are they normal?
Yes
Inspect the ATF condition.
• If large amount of metal specks are found, overhaul the transaxle and repair or replace any malfunctioning parts. (See Automatic Transaxle and Transfer Workshop Manual AW6A-EL AW6AX-EL.)
• If a large amount of metal specks are not found, replace the control valve body. (See CONTROL VALVE BODY REMOVAL/INSTALLATION [AW6A-EL, AW6AX-EL].)
No
Inspect the coupler component.
If normal, replace the control valve body.
(See CONTROL VALVE BODY REMOVAL/INSTALLATION [AW6A-EL, AW6AX-EL].)
7
• Verify test results.
― If normal, return to the diagnostic index to service any additional symptoms.
― If malfunction remains, inspect the related Service 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 range, and maintain in this condition for 3 s. Repeat this procedure 4 times. Then repeat it 5 times in the same way for R position.

3.Gear shift control learning

• In D range, with the accelerator opening between 25—30%, drive until you reach 6GR 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.