NO.17 SHIFT CONCERN: SOFT/SLIPPING 2-3 SHIFT [LA4AX-EL (CD4E)]


id0503a2804500

17

Shift concern: soft/slipping 2-3 shift

POSSIBLE CAUSE

• Powertrain control system malfunction
• Control valve body malfunction
• Oil pump malfunction
• Direct clutch component malfunction
2/4 servo malfunction
• Forward OWC component 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 fluid temperature (TFT) sensor
Yes
Perform OBD test
Perform DTC troubleshooting
No
Go to the next step
2
Control valve body
• Do any of the following malfunctions exist?
- Bolts are not tightened to the specification
- Gasket leaks
- Line modulator valve (also soft 1-2 and 3-4 shifts), servo release shuttle valve are stuck, damaged, or misassembled
- Hydraulic passages are damaged
- Separator plates are damaged
- Pressure tap plate/gasket leaks
Yes
Service if necessary
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
- Oil pump support seals #4 and #5 are damaged, or missing
Yes
Service if necessary
No
Go to the next step
4
Direct clutch component
• Do any of the following malfunctions exist?
- Seals or piston are damaged
- Piston bore is damaged
- Friction is damaged, worn, or excessive end clearance
- Inspect the ball for improper seating
- Return spring component is damaged
Yes
Service if necessary
No
Go to the next step
5
2/4 Servo
• Do any of the following malfunctions exist?
- Piston or piston bore is damaged
- Servo rod or rod bore is damaged
Yes
Service if necessary
No
Go to the next step
6
Forward OWC component
• Is the forward OWC component damaged or not holding?
Yes
Service if necessary
No
Go to the next step
7
Transaxle case
• Do any of the following malfunctions exist?
- Leakage in the servo apply, servo release or direct clutch circuits
Yes
Service 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.