NO.18 EXCESSIVE SHIFT SHOCK IS FELT WHEN UPSHIFTING AND DOWNSHIFTING [5R55S]

id0503c1804600

18

Excessive shift shock is felt when upshifting and downshifting

DESCRIPTION

•  Excessive shift shock felt when depressing accelerator pedal to accelerate at upshifting. During cruising, excessive shift shock is felt when depressing accelerator pedal at downshifting.

POSSIBLE CAUSE

•  Shift shock may worsen when fail-safe is operating. The shift shock may worsen if the signal from the accelerator pedal position sensor, TSS sensor, or OSS sensor has a malfunction.

1.  Clutch slipped, burned

•  Line pressure low, high

•  Shift solenoid D malfunction

•  Shift solenoid A malfunction

•  Shift solenoid B malfunction

•  Shift solenoid C malfunction

•  Pressure control solenoid B malfunction

•  Pressure control solenoid A malfunction

•  Pressure control solenoid C malfunction

•  Accelerator pedal position sensor misadjustment

•  Control valve body malfunction

•  Body ground malfunction

2.  Signal malfunction

•  TFT sensor malfunction

•  ISS sensor malfunction

•  Sensor ground malfunction

•  Accelerator pedal position sensor malfunction

•  VSS signal malfunction

•  IAT sendor malfunction

•  Digital TR sensor malfunction

3.  Poor hydraulic operation (Malfunction in range change)

•  Low fluid pressure

4.  Engine mounts installation

•  Loose attaching bolts

•  Worn parts

Note

•  Before the following the troubleshooting steps, make sure that the Automatic Transmission On-Board Diagnostic and Automatic Transmission Basic Inspections are conducted.
(See BASIC INSPECTION [5R55S].)

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, tighten or replace engine mounts.
2	Perform the stall test. (See MECHANICAL SYSTEM TEST [5R55S].) Is stall speed normal?	Yes	Go to the next step.
2		No	Repair or replace any malfunctioning parts.
3	Check the value at the following PCM PIDs using the IDS/PDS. (See PCM INSPECTION (Thailand, General (L.H.D. R.H.D.) specs.) [WL-C, WE-C].) • APP Are the PID values normal?	Yes	Go to the next step.
3		No	Repair or replace any malfunctioning parts.
4	Disconnect the TCM connector. Is the resistance between TCM ground terminal CO and body ground, and between TCM ground terminal CL and body ground less than 5.0 ohms?	Yes	Go to the next step.
4		No	Repair the wiring harness. Reconnect the TCM connector.
5	Inspect the PCA, PCB and PCC PID values. (See PID/DATA MONITOR INSPECTION [5R55S].) Are the PCA, PCB and PCC PID values normal?	Yes	Clean and inspect main control, if parts are damaged replace main control. If the problem remains, overhaul the transmission and repair or replace any malfunctioning parts.
5		No	Repair or replace any malfunctioning parts.
6	• Verify 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 repaired, the troubleshooting is completed. • If the vehicle the not repaired or additional diagnostic information is not available, replace the TCM.