NO.21 SHIFT CONCERN: SOFT/SLIPPING 2–1 SHIFT (AUTOMATIC OR KICKDOWN)[LA4AX-EL (CD4E)]

id0503a2805200

21

Shift concern: soft/slipping 2–1 shift (automatic or kickdown)

POSSIBLE CAUSE

•  Powertrain control system malfunction

•  Oil pump malfunction

•  2/4 band and servo component malfunction

•  Forward clutch component malfunction

•  Low one‐way clutch (OWC) component malfunction

21	Shift concern: soft/slipping 2–1 shift (automatic or kickdown)
POSSIBLE CAUSE	• Powertrain control system malfunction • Oil pump malfunction • 2/4 band and servo component malfunction • Forward clutch component malfunction • Low one‐way clutch (OWC) component 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 fluid temperature (TFT) sensor ― Throttle position (TP) sensor ― Mass air flow (MAF) 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	Oil pump • Do any of the following malfunctions exist? ― Gaskets are damaged ― Porosity/cross leaks ― Pump support seals #3 and 4 are leaking, misassembled, or damaged	Yes	Service if necessary
2		No	Go to the next step
3	2/4 band and servo component • Do either of the following malfunctions exist? ― Piston is damaged ― Return spring is damaged	Yes	Service if necessary
3		No	Go to the next step
4	Forward clutch component • Do either of the following malfunctions exist? ― Piston or seals are damaged ― Friction elements are damaged	Yes	Service if necessary
4		No	Go to the next step
5	Low OWC component • Is the low OWC damaged or not holding?	Yes	Service if necessary
5	Low OWC component • Is the low OWC damaged or not holding?	No	The malfunction is not in the automatic transaxle Go to the engine symptom troubleshooting (See ENGINE SYMPTOM TROUBLESHOOTING[AJ (3.0L Duratec)].)
6	• 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.