Inspection Procedure 9
INSPECTION PROCEDURE 9: Shift shocks and slippingCOMMENT
If shift shocks when driving due to upshifting or downshifting and the transaxle speed becomes higher than the engine speed, the cause is probably abnormal line pressure or a malfunction of a solenoid valve, oil pump, valve body or of a brake or clutch.
TROUBLESHOOTING HINTS (The most likely causes for this code to be set:)
- Abnormal line pressure
- Malfunction of each solenoid valve
- Malfunction of the oil pump
- Malfunction of the valve body
- Malfunction of the each brake or each clutch
- Malfunction of the PCM
DIAGNOSIS
REQUIRED SPECIAL TOOL:
- MB991502: Scan Tool (MUT-II)
CAUTION: To prevent damage to the scan tool MB991502, always turn the ignition switch to "LOCK" (OFF) position before connecting or disconnecting the scan tool MB991502.
STEP 1. Using scan tool MB991502, carry out the actuator test.
1) Connect scan tool MB991502 to the data link connector.
2) Check the following items in the actuator test.
a. Item 1: Low-reverse solenoid valve
b. Item 2: Underdrive solenoid valve
c. Item 3: Second solenoid valve
d. Item 4: Overdrive solenoid valve
3) Check that the solenoid valves click.
Q: Does the solenoids click?
YES: Go to Step 2.
NO: Repair or replace the solenoid valves. Then confirm that the symptom is eliminated.
STEP 2. Adjust the line pressure.
1) Adjust the line pressure. Then check the symptom.
Q: Is the symptom eliminated?
YES: Go to Step 3.
NO: Go to Step 4.
STEP 3. Check each brake and clutch.
1) Remove the transaxle.
2) Check the facing for seizure and piston seal ring for damage and interference with retainer. Repair or replace the faulty parts. Then check for the symptom.
Q: Is the symptom eliminated?
YES: Diagnosis is complete.
NO: Go to Step 6.
STEP 4. Replace the oil pump.
1) Remove the transaxle.
2) Replace the oil pump. (Oil pump can not be repaired). Then check the symptom.
Q: Is the symptom eliminated?
YES: Diagnosis is complete.
NO: Go to Step 5.
STEP 5. Disassemble and clean the valve body.
1) Check the O-ring installation bolts for looseness and the valve body for damage. Repair or replace the faulty parts.
Q: Is the repair possible and the symptom eliminated?
YES: Diagnosis is complete.
NO: Replace the valve body assembly. Then check the symptom. Go to Step 6.
STEP 6. Replace the PCM.
1) Replace the PCM. The immobilizer-ECU and the ignition key should be replaced together with it. Confirm that the malfunction symptom is eliminated.
Q: Is the symptom eliminated?
YES: Diagnosis is complete.
NO: Start over at Step 1.