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

id0503a3801900

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

•  APP sensor malfunction

•  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.

Diagnostic procedure

STEP	INSPECTION		ACTION
1	Is the line pressure normal? (See MECHANICAL SYSTEM TEST[GF4AX-EL].)	Yes	Go to the next step.
1		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 M-MDS 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 SOLENOID VALVE INSPECTION[GF4AX-EL].) If the shift solenoids are normal, inspect for open or short circuit between the PCM terminals 1E, 1F or 1G 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.