NO.18 EXCESSIVE SHIFT SHOCK IS FELT WHEN UPSHIFTING AND DOWNSHIFTING

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NO.18 EXCESSIVE SHIFT SHOCK IS FELT WHEN UPSHIFTING AND DOWNSHIFTING

B3E050319090W22

18 | Excessive shift shock is felt when upshifting and downshifting
DESCRIPTION | • Excessive shift shock is felt when depressing the accelerator pedal at upshifting. During cruising, excessive shift shock is felt when depressing the accelerator pedal at downshifting.

POSSIBLE CAUSE

• Shift shock may worsen when the fail-safe is operating. The shift shock has worsened if the TP sensor, input/turbine speed sensor, or vehicle speed sensor signal malfunctions.
1. Clutch slippage, burnt (Forward clutch, 2-4 brake band, 3-4 clutch)

  • Line pressure low, high
  • Shift solenoid D malfunction
  • Shift solenoid E malfunction
  • Shift solenoid A malfunction
  • Shift solenoid B malfunction
  • Shift solenoid C malfunction
  • Pressure control solenoid malfunction
  • Accelerator cable mis-adjustment
  • Control valve body malfunction
  • Body GND malfunction

2. Signal malfunction

  • Transaxle temperature sensor malfunction
  • Vehicle speed sensor malfunction
  • Sensor GND malfunction
  • TP sensor malfunction
  • Input/turbine speed sensor malfunction

3. Poor hydraulic operation (Malfunction in range change)

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

4. Engine mounts installation

  • Loose attaching bolts
  • Worn parts

  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 | Inspect the engine mounts for loose tightening bolts or worn parts. Are all engine mounts normal? | Yes | Go to the next step.
No | Readjust, retighten or replace engine mounts.
2 | Perform the stall test. (See Stall Test.) Is the stall speed normal? | Yes | Go to the next step.
No | Repair or replace any malfunctioning parts.
3 | Inspect the value at the following PCM PID using the WDS or equivalent. (See PCM INSPECTION [ZJ, Z6].) (See PCM INSPECTION [LF].) • TP V Is the PID value normal? | Yes | Go to the next step.
No | Repair or replace any malfunctioning parts.
4 | 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.
5 | Inspect the LPS PID value. Is the LPS PID value normal? (See PCM INSPECTION [ZJ, Z6].) (See PCM INSPECTION [LF].) | 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.

6

• Verify the test results.

  - If normal, return to the diagnostic index to service any additional symptoms.
  - If the malfunction remains, inspect the related Service information and perform repair or diagnosis.

  • If the vehicle is repaired, troubleshooting is completed.
  • If the vehicle is not repaired or additional diagnostic information is not available, replace the PCM.