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NO.17 EXCESSIVE SHIFT SHOCK FROM N TO D OR N TO R POSITION/RANGE [FN4A-EL]

BME050301030221

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.
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. 1. Clutch burnt (N→D: Forward clutch, N→R: Reverse clutch or low and reverse brake)

  • Line pressure low, high
  • TP sensor malfunction
  • Vehicle speed sensor malfunction
  • Input/turbine speed sensor malfunction
  • Shift solenoid B malfunction
  • Shift solenoid D malfunction
  • Shift solenoid A malfunction
  • Shift solenoid C malfunction
  • Pressure control solenoid malfunction
  • Accelerator cable mis-adjustment
  • Control valve body malfunction
  • Sensor GND malfunction
  • Body GND malfunction

2. Poor hydraulic operation (Malfunction in range change)

  • Forward accumulator malfunction
  • Servo apply accumulator malfunction
  • Pressure switch malfunction

3. Idle speed high
4. Poor tightening torque of engine mount, exhaust mount
5. Poor operation of mechanical pressure

  • Selector lever position disparity

  Note

  • Before following the troubleshooting steps, make sure that the Automatic Transaxle On-Board Diagnostic and Automatic Transaxle Basic Inspection are conducted.

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 | Disconnect the PCM connector. Is the resistance between the ground terminal at the PCM connector and the body ground less than 5.0 ohms? | Yes | Inspect the value at the following PCM PIDs using the WDS or equivalent. (See PCM INSPECTION [L3].) • TP • TFT • TFTV Repair or replace any malfunctioning parts.
No | Repair the open ground circuit. Reconnect the PCM.
3 | Perform the stall test. (See Stall Test.) Is the stall speed normal? | Yes | Go to the next step.
No | Go to Step 5.
4 | Inspect the value at the following PCM PID using the WDS or equivalent. (See PCM INSPECTION [L3].) • TR Is the PID value normal? | Yes | Overhaul the control valve body and repair or replace any malfunctioning parts. (See ATX workshop manual (FN4A-EL).) If any problem remains, overhaul the transaxle and repair or replace any malfunctioning parts. (See ATX workshop manual (FN4A-EL).)
No | Repair or replace any malfunctioning parts.
5 | Inspect the value at the following PCM PID using the WDS or equivalent. (See PCM INSPECTION [L3].) • TP Is the PID value normal? | Yes | Go to the next step.
No | Repair or replace any malfunctioning parts.
6 | Disconnect the PCM connector. Is the resistance between the ground terminal at the PCM connector and the body ground less than 5.0 ohms? | Yes | Go to the next step.
No | Repair the open ground circuit. Reconnect the PCM.
7 | Inspect the LPS PID value using the WDS or equivalent. Is the LPS PID value normal? (See PCM INSPECTION [L3].) | Yes | Overhaul the control valve body and repair or replace any malfunctioning parts. (See ATX workshop manual (FN4A-EL).) If any problem remains, overhaul the transaxle and repair or replace any malfunctioning parts. (See ATX workshop manual (FN4A-EL).)
No | Repair or replace any malfunctioning parts.