NO.17 EXCESSIVE SHIFT SHOCK FROM N TO D OR N TO R POSITION/RANGE [GF4AX-EL]


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 at idle.
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 • TP sensor malfunction • TFT sensor malfunction • Sensor GND malfunction • Throttle cable mis-adjustment • Control valve body malfunction 2. Poor hydraulic operation (Malfunction in range change) 3. Idle speed high 4. Poor tightening torque of engine mount, exhaust mount Note • Before following the troubleshooting steps, make sure that the Automatic Transaxle On-Board Diagnostic and Automatic Transaxle Basic Inspection are conducted.


STEP	INSPECTION		ACTION
1	Does the shift shock occur only when the engine is cold?	Yes	Go to the next step.
1	Does the shift shock occur only when the engine is cold?	No	Go to Step 3.
2	Connect the WDS or equivalent to DLC-2. Access TFT and TFTV PIDs. Drive the vehicle while monitoring PIDs. (See PCM INSPECTION [L3 R.H.D.].) Are the PIDs within the specification?	Yes	Go to the next step.
2		No	Inspect the TFT sensor and related wiring harness: for intermittent open/short circuit during vibration.
3	Is the line pressure normal? (See Line Pressure Test.)	Yes	Go to the next step.
3	Is the line pressure normal? (See Line Pressure Test.)	No	Repair or replace any malfunctioning parts according to the inspection results.
4	Is the stall speed normal? (See Stall Speed Test.)	Yes	Go to the next step.
4	Is the stall speed normal? (See Stall Speed Test.)	No	Go to Step 6.
5	Inspect the value at the following PCM PIDs using the WDS or equivalent to DLC-2. (See PCM INSPECTION [L3 R.H.D.].) • TRD • TRR • TR Are the PIDs values normal?	Yes	Replace the control valve body and repair or replace any malfunctioning parts. (See ATX Workshop Manual (GF4AX-EL)) If any problem remains, replace the transaxle and repair or replace any malfunctioning parts. (See ATX Workshop Manual (GF4AX-EL))
5		No	Inspect the TR switch and related wiring harness: for intermittent open/short circuit during vibration.
6	Stop the engine and turn the ignition switch to the ON position. Connect the WDS or equivalent to DLC-2. Simulate LPS PID for 50%. Is operating sound of the pressure control solenoid heard?	Yes	Replace the control valve body and repair or replace any malfunctioning parts. (See ATX Workshop Manual (GF4AX-EL)) If any problem remains, replace the transaxle and repair or replace any malfunctioning parts. (See ATX Workshop Manual (GF4AX-EL))
6		No	Inspect of the pressure control solenoid terminal on the ATX for bent terminals, damage, corrosion or looseness. Inspect for stuck pressure control solenoid? (See Operating Inspection (On-vehicle Inspection).) If the pressure control solenoid normal, inspect for open or short circuit between the PCM terminal 91 and the pressure control solenoid terminal G.
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 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.