NO.23 SHIFT CONCERN: HARSH 2–3 SHIFT[LA4AX-EL (CD4E)]

id0503a2805500

23

Shift concern: harsh 2–3 shift

POSSIBLE CAUSE

•  Powertrain control system malfunction

•  Control valve body malfunction

•  Oil pump malfunction

•  Direct clutch component malfunction

•  2/4 servo malfunction

•  Transaxle case malfunction

23	Shift concern: harsh 2–3 shift
POSSIBLE CAUSE	• Powertrain control system malfunction • Control valve body malfunction • Oil pump malfunction • Direct clutch component malfunction • 2/4 servo malfunction • Transaxle case malfunction

Diagnostic procedure

STEP	INSPECTION		ACTION
1	Powertrain control system • Are there any malfunctions with the following? ― Electrical input/output ― Vehicle wiring harness ― PCM ― Electrical pressure control (EPC) solenoid ― Transaxle range (TR) switch ― Vehicle speedometer sensor (VSS) ― Transaxle fluid temperature (TFT) sensor ― Mass air flow (MAF) sensor ― TCC solenoid ― Turbine shaft speed (TSS) sensor	Yes	Perform OBD test Perform DTC troubleshooting (See AUTOMATIC TRANSAXLE ON-BOARD DIAGNOSTIC FUNCTION[LA4AX-EL (CD4E)].)
1		No	Go to the next step
2	Control valve body • Do any of following malfunctions exist? ― Bolts are not tightened to the specification ― Gasket leaks ― Line modulator valve (also 1-2 and 3-4 harsh shift), servo release shuttle valve are stuck, damaged, or misassembled ― Separator plates are damaged ― Hydraulic passages are damaged	Yes	Service if necessary
2		No	Go to the next step
3	Oil pump • Do any of the following malfunctions exist? ― Bolts are not tightened to the specification ― Gasket is damaged ― Porosity/cross leakage ― Pump support seal rings #4 and #5 are damaged	Yes	Service if necessary
3		No	Go to the next step
4	Direct clutch component • Do any of the following malfunctions exist? ― Piston or piston bore is damaged ― Friction elements are damaged or worn ― Inspect the check ball for improper seating ― Return spring component is damaged ― Forward/coasting/direct (F/C/D) clutch cylinder splines are damaged	Yes	Service if necessary
4		No	Go to the next step
5	2/4 Band Servo • Do either of the following malfunctions exist? ― Piston or piston bore is damaged ― Servo rod is damaged	Yes	Service if necessary
5		No	Go to the next step
6	Transaxle Case • Do either of the following malfunctions exist? ― Leakage in the servo apply, servo release, or direct clutch circuits ― Servo rod bore is damaged	Yes	Service if necessary
6		No	The malfunction is not in the automatic transaxle Go to the engine symptom troubleshooting (See ENGINE SYMPTOM TROUBLESHOOTING[AJ (3.0L Duratec)].)
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.