NO.22 SHIFT CONCERN: HARSH 1-2 SHIFT [LA4AX-EL (CD4E)]


id0503a2805400

22

Shift concern: harsh 1-2 shift

POSSIBLE CAUSE

• Powertrain control system malfunction
• Control valve body malfunction
• Oil pump malfunction
2/4 band and servo component malfunction
• Forward 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
- Transaxle fluid temperature (TFT) sensor
- Turbine shaft speed (TSS) sensor
- Throttle position (TP) sensor
- Vehicle speedometer sensor (VSS)
- Mass air flow (MAF) sensor
- TCC
- Transaxle range (TR) switch
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
- 2/4 accumulator valve, 3-2 control valve (also harsh 3-4 shift) 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
- Gaskets are damaged
- Oil pump support seal rings #3 and #4 are damaged
- Porosity/cross leakage
Yes
Service if necessary
No
Go to the next step
4
2/4 band and servo component
• Do any of the following malfunctions exist?
- Cushion return springs are damaged
- Band is damaged, worn
- 2/4 band and/or reverse clutch drum component are worn, damaged, or misassembled
Yes
Service if necessary
No
Go to the next step
5
Forward clutch component
• Do any of the following malfunctions exist?
- Seals are damaged
- Return spring is damaged
- Friction elements are damaged
Yes
Service if necessary
No
Go to the next step
6
Transaxle case
• Is the band anchor area 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.