NO.14 ENGINE FLARES UP OR SLIPS WHEN UPSHIFTING OR DOWNSHIFTING [GF4AX-EL]


14	Engine flares up or slips when upshifting or downshifting
DESCRIPTION	• When the accelerator pedal is depressed for driveway, engine speed increases but vehicle speed increases slowly. • When the accelerator pedal depressed while driving, engine speed increases but the vehicle does not.
POSSIBLE CAUSE	• There is clutch slippage because the clutch is stuck or the line pressure is low. 1. Clutch stuck, slippage (forward clutch, 3-4 clutch, 2-4 brake band, one-way clutch 1, one-way clutch 2) • Line pressure low • TP sensor malfunction or mis-adjustment • VSS malfunction • Input/turbine speed sensor malfunction • Sensor GND malfunction • Shift solenoid A, B, or C malfunction • TCC solenoid valve malfunction • Body GND malfunction • Throttle cable mis-adjustment • Control valve body malfunction 2. Poor operation of mechanical pressure • Selector lever position disparity • TR switch position disparity 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	Is the line pressure normal? (See Line Pressure Test.)	Yes	Go to the next step.
1	Is the line pressure normal? (See Line Pressure Test.)	No	Repair or replace any malfunctioning parts according to inspection results.
2	Is the shift point normal? (See ROAD TEST [GF4AX-EL].)	Yes	Go to the next step.
2	Is the shift point normal? (See ROAD TEST [GF4AX-EL].)	No	Go to No.9 "ABNORMAL SHIFTING".
3	Stop the engine and turn the ignition switch to the ON position. Connect the WDS or equivalent to DLC-2. Simulate SSA/SS1, SSB/SS2 and SSC/SS3 PIDs for ON. Is operating sound of the shift solenoids 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))
3		No	Inspect connection of the shift solenoid A, B, or C terminal on the ATX for bent terminals, damage, corrosion or looseness. Inspect for stuck shift solenoid. (See Operating Inspection (On-vehicle Inspection).) If the shift solenoids are normal, inspect for open or short circuit between the PCM terminals 92, 66 or 40 and the shift solenoids terminals A, B, or C.
4	• 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.