NO.14 ENGINE FLARES UP OR SLIPS WHEN UPSHIFTING OR DOWNSHIFTING [FS5A-EL]

id050308801900

14

Engine flares up or slips when upshifting or downshifting

DESCRIPTION

•  When the accelerator pedal is depressed, engine speed increases normally but vehicle speed increases slowly.

•  When the accelerator pedal is depressed while driving, engine speed increases but vehicle speed does not increase.

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)

•  Line pressure low

•  Shift solenoid A malfunction

•  Shift solenoid B malfunction

•  Shift solenoid C malfunction

•  Shift solenoid D malfunction

•  Shift solenoid E malfunction

•  Shift solenoid F malfunction

•  Pressure control solenoid A malfunction

•  Control valve body malfunction

•  Body GND malfunction

2.  Signal malfunction

•  APP sensor malfunction

•  Input/turbine speed sensor malfunction

•  VSS malfunction

•  Sensor GND malfunction

3.  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. (See ON-BOARD DIAGNOSTIC SYSTEM DTC INSPECTION [FS5A-EL].) (See BASIC INSPECTION [FS5A-EL].)

Diagnostic procedure

STEP	INSPECTION		ACTION
1	Is the shift point normal?	Yes	Go to the next step.
1	Is the shift point normal?	No	Perform the symptom troubleshooting “NO.9 ABNORMAL SHIFTING”. (See NO.9 ABNORMAL SHIFTING [FS5A-EL].)
2	Inspect the THOP PID value using the M-MDS. (See ON-BOARD DIAGNOSTIC SYSTEM PID/DATA MONITOR INSPECTION [FS5A-EL].) Is the PID value normal?	Yes	Go to the next step.
2		No	Repair or replace any malfunctioning parts.
3	Disconnect the TCM connector. Measure the resistance between ground terminal at the TCM connector and body ground. Is the resistance less than 5.0 ohms?	Yes	Go to the next step.
3		No	Repair or replace the wiring harness for a possible open circuit.
4	Inspect the LPS PID value using the M-MDS. (See ON-BOARD DIAGNOSTIC SYSTEM PID/DATA MONITOR INSPECTION [FS5A-EL].) Is the PID value normal?	Yes	Overhaul the control valve body and repair or replace any malfunctioning parts. (See ATX workshop manual [FS5A-EL].) If any problem remains: • Overhaul the transaxle and repair or replace any malfunctioning parts. (See ATX workshop manual [FS5A-EL].)
4		No	Repair or replace any malfunctioning parts.
5	• 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 TCM. (See TCM REMOVAL/INSTALLATION [FS5A-EL].)