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 B4 brake)

• ATF level low

• Line pressure low

• Incorrect throttle position signal

• Incorrect accelerator pedal position signal

• Incorrect engine speed signal

• Incorrect engine coolant temperature signal

• Incorrect engine torque signal

• Incorrect turbine sensor signal (N→D)

• TFT sensor malfunction

• Sensor GND malfunction

• Shift solenoid A malfunction

• Shift solenoid F malfunction

• Line pressure control solenoid malfunction

• TCC control solenoid malfunction (N→R)

• Control valve body malfunction

• Poor hydraulic operation (Malfunction in range change)

• Idle speed high

• Poor tightening torque of engine mount, exhaust mount, suspension, propeller shaft

• Line pressure high

• Insufficient battery voltage

• Harness or connector malfunction

• AT malfunction

NOTE:

• Before following the troubleshooting steps, make sure that the Automatic Transmission On-Board Diagnostic and Automatic Transmission Basic Inspection are conducted. (See BASIC INSPECTION [SJ6A-EL].)

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 TRANSMISSION FLUID TEMPERATURE (TFT) SENSOR INSPECTION [SJ6A-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[SJ6A-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[SJ6A-EL].)

Yes

Go to the next step.

No

Repair or replace any malfunctioning parts according to the inspection results.

6

• Access the following PCM PIDs using the M-MDS.

• RPM

• APP

• TP

• ECT

• ENG_TRQ

• Are PIDs value normal?

Yes

Go to the next step.

No

Inspect and repair suspected PID related part.

7

• Stop the engine.

• Inspect following solenoids.

  (See SOLENOID VALVE INSPECTION [SJ6A-EL].)

• Line pressure control solenoid

• Shift solenoid A

• Shift solenoid F

• TCC control solenoid

• Are they normal?

Yes

Inspect the ATF condition.

• If a large amount of metal specks are found, replace the transmission.

  (See AUTOMATIC TRANSMISSION REMOVAL/INSTALLATION [SJ6A-EL].)

• If a large amount of metal specks are not found, replace the control valve body.

  (See CONTROL VALVE BODY REMOVAL [SJ6A-EL].)

  (See CONTROL VALVE BODY INSTALLATION [SJ6A-EL].)

No

• Replace the control valve body.

  (See CONTROL VALVE BODY REMOVAL [SJ6A-EL].)

  (See CONTROL VALVE BODY INSTALLATION [SJ6A-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.