Inspection Procedure 2
INSPECTION PROCEDURE 2: Does not move forwardCOMMENT
If the vehicle does not move forward when the selector lever is shifted from "N" to "D," "2" or "L" range while the engine is idling, the cause is probably abnormal line pressure or a malfunction of the underdrive clutch or valve body.
TROUBLESHOOTING HINTS (The most likely causes for this case:)
- Abnormal line pressure
- Malfunction of the underdrive solenoid valve
- Malfunction of the underdrive clutch
- Malfunction of the valve body
- 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 item in the actuator test.
a. Item 2: Underdrive solenoid valve
3) Check that the solenoid valve clicks.
NOTE:: The engine must not be running for this test.
Q: Does the solenoid click?
YES: Go to Step 2.
NO: Confirm the PCM is operating the solenoid by checking voltages at PCM terminal 120, connector C121 <2.4L Engine> or C-123 <3.0L Engine>. If operating properly, replace the underdrive solenoid valve. Then confirm that the symptom is eliminated.
STEP 2. Check the hydraulic pressure.
1) Measure the hydraulic pressure of each element when the selector lever is at the "L" range, and check if each hydraulic pressure is within the standard value.
Q: Is the hydraulic pressure within the standard value?
YES: Go to Step 3.
NO: Go to Step 4.
STEP 3. Check the underdrive clutch system.
1) Remove the valve body cover and valve body.
2) Blow compressed air into the underdrive clutch oil orifice of the transaxle case, and check if the underdrive clutch piston moves and air pressure is maintained in that condition.
Q: Is the air pressure maintained?
YES: Go to Step 4.
NO: Go to Step 5.
STEP 4. Disassemble and clean the valve body.
1) Check the O-ring installation bolts for looseness and 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. If the symptom is not eliminated, go to Step 6.
STEP 5. Check the underdrive clutch.
1) Remove the transaxle assembly.
2) Check the facing for seizure and the piston seal ring for damage and interference with the retainer. Repair or replace the faulty parts. Then check the symptom.
Q: Is the symptom eliminated?
YES: Diagnosis is complete.
NO: 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.