NO.14 ENGINE FLARES UP OR SLIPS WHEN UPSHIFTING OR DOWNSHIFTING[FN4A-EL]

id0503a1801900

14

Engine flares up or slips when upshifting or downshifting

DESCRIPTION

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

•  When the accelerator pedal is 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)

•  Line pressure low

•  Shift solenoid D malfunction

•  Shift solenoid E malfunction

•  Shift solenoid A malfunction

•  Shift solenoid B malfunction

•  Shift solenoid C malfunction

•  Pressure control solenoid malfunction

•  Body GND malfunction

•  Accelerator cable mis-adjustment

•  Control valve body malfunction

2.  Signal malfunction

•  Vehicle speed sensor malfunction

•  Sensor GND malfunction

•  TP sensor malfunction or mis-adjustment

•  APP sensor malfunction

•  Input/turbine speed sensor 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.

Diagnostic procedure

STEP	INSPECTION		ACTION
1	Is shift point normal?	Yes	Go to the next step.
1	Is shift point normal?	No	Go to No.9 “ABNORMAL SHIFTING”.
2	Inspect the value at the following PCM PID using the M-MDS. (See PCM INSPECTION[ZJ, ZY, Z6].) (See PCM INSPECTION[LF, L3].) • TP • TP1 • APP1 • APP2 Is the PID value normal?	Yes	Go to the next step.
2		No	Repair or replace any malfunctioning parts.
3	Disconnect the PCM connector. Is the resistance between the ground terminal at the PCM connector and the body ground less than 5.0 ohms?	Yes	Go to the next step.
3		No	Repair the open ground circuit. Reconnect the PCM.
4	Inspect the LPS PID value. Is the LPS PID value normal? (See PCM INSPECTION[ZJ, ZY, Z6].) (See PCM INSPECTION[LF, L3].)	Yes	Overhaul the control valve body and repair or replace any malfunctioning parts. (See ATX workshop manual (FN4A-EL).) If any problem remains, overhaul the transaxle and repair or replace any malfunctioning parts. (See ATX workshop manual (FN4A-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 PCM.