NO.18 EXCESSIVE SHIFT SHOCK IS FELT WHEN UPSHIFTING AND DOWNSHIFTING[FN4A-EL]

id0503a1804600

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

•  APP sensor malfunction

•  Input/turbine speed sensor malfunction

3.  Poor hydraulic operation (Malfunction in range change)

•  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.
1		No	Readjust, retighten or replace engine mounts.
2	Perform the stall test. (See MECHANICAL SYSTEM TEST[FN4A-EL].) Is the stall speed normal?	Yes	Go to the next step.
2		No	Repair or replace any malfunctioning parts.
3	Inspect the value at the following PCM PID using the M-MDS. (See PCM INSPECTION[ZJ, ZY, Z6].) (See PCM INSPECTION[LF, L3].) • TP V • APP1 • APP2 • TP1 Is the PID value normal?	Yes	Go to the next step.
3		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.
4		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, ZY, Z6].) (See PCM INSPECTION[LF, 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).)
5		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.