NO.1 NO FORWARD ENGAGEMENT ONLY[LA4AX-EL (CD4E)]

id0503a2803600

1

No forward engagement only

POSSIBLE CAUSE

•  Internal or external shift linkage malfunction

•  Oil pump malfunction

•  Control valve body malfunction

•  Forward clutch and coasting clutch component malfunction

•  Low one-way clutch component malfunction

•  Forward one-way clutch component malfunction

•  Low intermediate carrier component malfunction

1	No forward engagement only
POSSIBLE CAUSE	• Internal or external shift linkage malfunction • Oil pump malfunction • Control valve body malfunction • Forward clutch and coasting clutch component malfunction • Low one-way clutch component malfunction • Forward one-way clutch component malfunction • Low intermediate carrier component malfunction

Diagnostic procedure

STEP	INSPECTION		ACTION
1	Internal or external shift linkages • Do any of the following malfunctions exist? ― Damage ― Misadjustment ― Misassembly	Yes	Service if necessary
1		No	Go to the next step
2	Control valve body • Do any of the following malfunctions exist? ― Bolts are not tightened to the specification ― Gaskets are damaged, or leaking ― Pressure tap plate/Gasket are leaking or damaged ― Separator plates are damaged ― Hydraulic passages are damaged ― Main regulator valve is stuck, damaged, or misassembled ― Forward accumulator is leaking	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 ― Gaskets are damaged ― Porosity/cross leaks and/or the ball plug is missing, leaking, or the hole is plugged ― Oil pump support seal rings, #3 and #4 are damaged	Yes	Service if necessary
3		No	Go to the next step
4	Forward clutch and coasting clutch component • Do any of the following malfunctions exist? ― Seals or pistons damaged ― Return spring is damaged ― Ball check valve is damaged ― Friction elements are severely damaged or worn ― Forward/coasting/direct (F/C/D) clutch cylinders are damaged, leaking, misassembled, or stuck ― Welding between cylinder and hub is broken, or splines are damaged	Yes	Service if necessary
4		No	Go to the next step
5	Low one-way clutch component • Do any of the following malfunctions exist? ― Wear ― Damage ― Misassembly	Yes	Service if necessary
5		No	Go to the next step
6	Forward one-way clutch component • Do any of the following malfunctions exist? ― Wear ― Damage ― Misassembly	Yes	Service if necessary
6		No	Go to the next step
7	Low intermediate carrier • Do any of the following malfunctions exist? ― Damage ― Misassembly	Yes	Service if necessary
7		No	The problem is resolved
8	• 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.