NO.20 SHIFT CONCERN: SOFT/SLIPPING 3-2 SHIFT (AUTOMATIC) [LA4AX-EL (CD4E)]


id0503a2805000

20

Shift concern: soft/slipping 3-2 shift (automatic)

POSSIBLE CAUSE

• Powertrain control system malfunction
• Control valve body malfunction
• Oil pump malfunction
2/4 band and servo component malfunction
• Direct clutch 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
- Throttle position (TP) sensor
- Vehicle speedometer sensor (VSS)
- Mass air flow (MAF) sensor
- 3-2 timing/coasting clutch solenoid (3-2T/CCS)
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 is damaged
- 3-2 Timing valve, solenoid regulator valve, 3-2 control valve are stuck, damaged, or misassembled
- 3-2T/CCS solenoid malfunction
- Pressure tap plate/gasket leaks or is damaged
- Separator plates are damaged or blocked
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
- Porosity/cross leaks
- Pump support seal Rings #4, 5, 6 are damaged or misassembled
- Forward to direct passage leaks
Yes
Service if necessary
No
Go to the next step
4
2/4 band and servo component
• Do any of the following malfunctions exist?
- 2/4 band and/or reverse clutch drum component are damaged, worn, or misassembled
- Servo piston are damaged
- Servo return and cushion springs are damaged, or misassembled
- Springs are damaged or misassembled
- Servo rod is bent or damaged
Yes
Service if necessary
No
Go to the next step
5
Direct clutch component
• Do any of the following malfunctions exist?
- Return spring is damaged or broken
- Friction elements is damaged or worn
- The check ball is not releasing
- Piston or seal is damaged
Yes
Service if necessary
No
Go to the next step
6
Transaxle case
• Do any of the following malfunctions exist?
- Band anchor is damaged
- Leakage in the servo apply/release circuits
- Case bore is damaged (Servo Rod)
Yes
Service if necessary
No
The malfunction is not in the automatic transaxle
Go to the engine symptom troubleshooting
7
• 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.