NO.17 EXCESSIVE SHIFT SHOCK FROM N TO D OR N TO R POSITION [SJ6A-EL]

id050307823700

17
Excessive shift shock from N to D or N to R position
DESCRIPTION
•  Strong shock is 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 B4 brake)
•  ATF level low
•  Line pressure low
•  Incorrect accelerator pedal position signal
•  Incorrect engine speed signal
•  Incorrect engine coolant temperature signal
•  Incorrect brake switch signal
•  Incorrect engine torque signal
•  Incorrect turbine sensor signal (N→D)
•  TFT sensor malfunction
•  Sensor ground 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 position 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

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).
•  Is it normal?
Yes
Go to the next step.
No
Repair or replace the malfunctioning part according to the inspection results.
3
•  Perform the initial learning procedure.
•  Does the symptom eliminate?
Yes
Symptom troubleshooting is completed.
No
Go to the next step.
4
•  Is the line pressure normal?
Yes
Go to the next step.
No
Repair or replace the malfunctioning part according to the inspection results.
5
•  Is the stall speed normal?
Yes
Go to the next step.
No
Repair or replace the malfunctioning part according to the inspection results.
6
•  Access the following PCM PIDs using the M-MDS:
―  RPM
―  APP
―  TP_REL
―  BOO
―  ECT
•  Are the PIDs value normal?
Yes
Go to the next step.
No
Repair or replace the malfunctioning part according to the inspection results.
7
•  Stop the engine.
•  Inspect the following solenoids:
―  Line pressure control solenoid
―  Shift solenoid A
―  Shift solenoid F
―  TCC control solenoid
•  Are these solenoids normal?
Yes
Inspect the ATF condition.
•  If a large amount of metal specks are found, overhaul the transmission and repair or replace any malfunctioning parts.
(See Automatic Transmission Workshop Manual [SJ6A-EL].)
•  If a large amount of metal specks are not found, replace the control valve body.
No
•  Replace the control valve body.
8
•  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. (See TCM REMOVAL/INSTALLATION [SJ6A-EL].)