NO.20 EXCESSIVE SHIFT SHOCK IS FELT WHEN UPSHIFTING AND DOWNSHIFTING


20	Excessive shift shock is felt when upshifting and downshifting
DESCRIPTION	• Excessive shift shock is felt when depressing accelerator pedal at upshifting. During cruising, excessive shift shock is felt when depressing accelerator pedal at downshifting.
POSSIBLE CAUSE	• Clutch slippage (low clutch, high clutch) – In the event of clutch slippage, a DTC (incorrect gear ratio) is output. • Reduced line pressure • Input/output signal malfunction (VSS, turbine sensor, throttle opening angle (CAN communication), TFT sensor, pressure control solenoid, shift solenoids A, B, C and F, oil pressure switches B, C and F). • Control valve body malfunction (improper operation, stuck, clogged oil passage) – Hydraulic circuit clogging (Pressure control solenoid, shift solenoids B, C and F) – Control valve spool malfunction – Improper operation of accumulator (Low solenoid, 2-4 brake solenoid, high clutch solenoid, low and reverse brake solenoid, 2-4 brake, high clutch) • Improper TCM ground • Improper ground of GND return line in AT – If there is improper ground of GND return line, clutch pressure may decrease, causing clutch slippage. Note • The malfunction is basically the same as for No.16 "ENGINE FLARES UP OR SLIPS WHEN UPSHIFTING OR DOWNSHIFTING". • Before following the troubleshooting steps, make sure that the Automatic Transmission On-Board Diagnostic and Automatic Transmission Basic Inspection are conducted. (See BASIC INSPECTION.)


STEP	INSPECTION		ACTION
1	Perform the stall test. (See Stall Speed Test.) Is the stall speed normal?	Yes	Go to the next step.
1		No	Repair or replace any malfunctioning parts.
2	Inspect the following values. (See PCM INSPECTION.) (See TCM INSPECTION.) • APP1 • APP2 PCM PIDs (using WDS or equivalent) • TP_REL • VSS TCM terminal voltage: • 2G (turbine sensor) • 2K (VSS) Are the values normal?	Yes	Go to the next step.
2		No	Repair or replace any malfunctioning parts.
3	Disconnect the TCM connector. Is the resistance between terminal 2U at the TCM connector and terminal J at the solenoid valve wiring harness-side connector 5.0 ohms or less?	Yes	Go to the next step.
3		No	Repair open circuit.
4	Is the resistance between ground terminal 2M or 2Q at the TCM connector and body ground 5.0 ohms or less?	Yes	Go to the next step.
4		No	Repair the wiring harness. Reconnect the TCM.
5	Inspect the TFT sensor. (See TRANSMISSION FLUID TEMPERATURE (TFT) SENSOR INSPECTION.) Is the TFT sensor normal?	Yes	Go to the next step.
5		No	Replace the TFT sensor.
6	Stop the engine. Disconnect the solenoid valve connector. Measure the resistance between the following solenoid valve connector terminals. (See SOLENOID VALVE INSPECTION.) • Terminals E-J (shift solenoid A) • Terminals F-J (shift solenoid B) • Terminals H-J (shift solenoid C) • Terminals I-J (shift solenoid F) • Terminals K-J (pressure control solenoid) Are the resistances normal?	Yes	Overhaul the control valve body and repair or replace any malfunctioning parts. (See AT Workshop Manual.) If the problem remains, overhaul the transmission and repair or replace any malfunctioning parts. (See AT Workshop Manual)
6		No	Repair or replace malfunctioning parts.
7	Verify the test results. • If normal, return to the diagnostic index to service any additional symptoms. • If the malfunction remains, inspect the related Service Bulletins and/or On-line Repair 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.)