NO.23 SHIFT CONCERN: HARSH 2-3 SHIFT [LA4AX-EL (CD4E)]


id0503a2805500

23

Shift concern: harsh 2-3 shift

POSSIBLE CAUSE

• Powertrain control system malfunction
• Control valve body malfunction
• Oil pump malfunction
• Direct clutch component malfunction
2/4 servo 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 range (TR) switch
- Vehicle speedometer sensor (VSS)
- Transaxle fluid temperature (TFT) sensor
- Mass air flow (MAF) sensor
- TCC solenoid
- Turbine shaft speed (TSS) sensor
Yes
Perform OBD test
Perform DTC troubleshooting
No
Go to the next step
2
Control valve body
• Do any of following malfunctions exist?
- Bolts are not tightened to the specification
- Gasket leaks
- Line modulator valve (also 1-2 and 3-4 harsh shift), servo release shuttle valve are stuck, damaged, or misassembled
- Separator plates are damaged
- Hydraulic passages are damaged
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
- Gasket is damaged
- Porosity/cross leakage
- Pump support seal rings #4 and #5 are damaged
Yes
Service if necessary
No
Go to the next step
4
Direct clutch component
• Do any of the following malfunctions exist?
- Piston or piston bore is damaged
- Friction elements are damaged or worn
- Inspect the check ball for improper seating
- Return spring component is damaged
- Forward/coasting/direct (F/C/D) clutch cylinder splines are damaged
Yes
Service if necessary
No
Go to the next step
5
2/4 Band Servo
• Do either of the following malfunctions exist?
- Piston or piston bore is damaged
- Servo rod is damaged
Yes
Service if necessary
No
Go to the next step
6
Transaxle Case
• Do either of the following malfunctions exist?
- Leakage in the servo apply, servo release, or direct clutch circuits
- Servo rod bore is damaged
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.