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
(See Line Pressure Test.)
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 Bulletins and/or On-line Repair 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.