Inspection Procedure 2
COMMENTIf the vehicle backs up but 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 scan tool MB991502, always turn the ignition switch to "LOCK" (OFF) position before connecting or disconnecting 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. Refer to Actuator Test Reference Table.
a. Item 2: Underdrive solenoid valve
3. Check that the solenoid valve clicks.
NOTE: The engine must not be running for this test
If the solenoid clicks, go to Step 2.
If the clicks cannot be heard, confirm the PCM is operating the solenoid by checking voltages at PCM terminal 120, connector C-61 <2.4L Engine> or C-63 <3.0L Engine>. If operating properly, replace the underdrive solenoid valve. Refer to Valve Body. Then confirm that the symptom is eliminated.
STEP 2. Check The Hydraulic Pressure.
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. Refer to Hydraulic Pressure Test. Hydraulic Pressure Tests
If within the standard value, go to Step 3.
If not within the standard value, 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.
If the air pressure is maintained, go to Step 4.
If the air pressure is not maintained, go to Step 5.
STEP 4. Disassemble And Clean The Valve Body.
Check the O-ring installation bolts for looseness and valve body for damage. Repair or replace the faulty parts. Refer to Valve Body.
If repair is not possible, replace the valve body assembly. Then check the symptom.
If the symptom is eliminated, diagnosis is complete.
It the symptom is not eliminated, go to Step 6.
STEP 5. Check The Underdrive Clutch.
Remove the transaxle assembly.
Check the facing for seizure and the piston seal ring for damage and interference with the retainer. Repair or replace the faulty parts. Refer to Underdrive Clutch and Input Shaft. Then check the symptom.
If the symptom is eliminated, diagnosis is complete.
it the symptom is not eliminated, go to Step 6.
STEP 6. Replace The PCM.
Replace the PCM. The immobilizer-ECU and the ignition key should be replaced together with it. Refer to Ignition Switch and Immobilizer System - Ignition Switch and Immobilizer System. Confirm that the malfunction symptom is eliminated.
If malfunction is eliminated, diagnosis is complete.