NO.13 SHIFT CONCERN: NO 1–2 SHIFT[LA4AX-EL (CD4E)]


id0503a2804100

13

Shift concern: no 1–2 shift

POSSIBLE CAUSE
•  Powertrain control system malfunction
•  Improper pressure
•  Control valve body malfunction
•  2/4 band and servo malfunction
•  Low OWC component malfunction
•  Reverse/fourth gear (REV/4GR) sun gear and shell malfunction
•  Transaxle case malfunction

Diagnostic procedure

STEP

INSPECTION

ACTION

1
Powertrain control system
•  Do any of the following malfunctions exist?
―  Electrical input/output
―  Vehicle wiring harness
―  PCM
―  Shift solenoid No.1 (SS1), Shift solenoid No.2 (SS2)
―  Transaxle range (TR) switch
Yes
Perform OBD test
Perform DTC troubleshooting
No
Go to the next step
2
Improper pressure
•  Do any of the following malfunctions exist?
―  High line pressure
―  Low line pressure
Yes
Go to the next step
No
Go to step 4
3
Control valve body
•  Do any of the following malfunctions exist?
―  Bolts are not tightened to the specification
―  Gaskets are damaged
―  1-2 shift valve, 2/4 accumulator, main regulator valve are stuck, damaged, or misassembled
―  SS1, SS2 malfunction
―  Pressure tap plate/gasket are damaged
―  Separator plates are damaged
―  Hydraulic passages are damaged
Yes
Service if necessary
No
Go to the next step
4
2/4 band and servo component
(No fourth gear engagement also)
•  Do any of the following malfunctions exist?
―  Seals are damaged or missing
―  Piston is damaged
―  Band is damaged or worn
―  Springs are damaged
―  Servo rod or rod bore is damaged
Yes
Service if necessary
No
Go to the next step
5
Low OWC component
•  Is there any damage?
Yes
Service if necessary
No
Go to the next step
6
Reverse/fourth gear sun gear and shell
•  Do any of the following malfunctions exist?
―  Damaged, or broken weld
―  Lugs are damaged
Yes
Service if necessary
No
Go to the next step
7
Transaxle case
•  Do any of the following malfunctions exist?
―  Band anchor area is damaged
―  Porosity/leakage in servo apply, servo release circuits
Yes
Service or replace case if necessary
No
The malfunction is not in the automatic transaxle
Go to the engine symptom troubleshooting
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.