Inspection Procedure 3: Does not Move Forward
COMMENTS ON TROUBLE SYMPTOM
If the vehicle does not move forward when the selector lever is shifted N to D range while the engine is idling, the cause is probably abnormal line pressure or a malfunction of the underdrive clutch or valve body.
PROBABLE CAUSES
- Malfunction of underdrive solenoid valve
- Malfunction of inhibitor switch
- Abnormal line pressure
- Malfunction of the underdrive clutch
- Malfunction of valve body
- Malfunction of the oil pump
- Malfunction of the A/T-ECU <4M4>
- Malfunction of the engine-A/T-ECU <6G7>
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STEP 1. M.U.T.-III actuator test
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Item 2: Underdrive solenoid valve
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OK: Operating sound can be heard.
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Q.
Is the check result normal?
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Go to Step 2.
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Replace the underdrive solenoid valve.
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STEP 2. M.U.T.-III diagnosis code
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Either of diagnosis codes P1770 (P0705) or P1771 (P0705) is set, inhibitor switch is defective.
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Q.
Are diagnosis codes P1770 (P0705) or P1771 (P0705) set?
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YES diagnosis code P1770 (P0705) is set : Refer to diagnosis code P1770 (P0705): Inhibitor switch system .
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YES diagnosis code P1771 (P0705) is set : Refer to diagnosis code P1771 (P0705): Inhibitor switch system .
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Go to Step 3.
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STEP 3. Underdrive solenoid valve check
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(1)Turn the ignition switch to the ON position.
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(2)Shift the selector lever from N to D range.
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(3)Confirm the operating sound of the underdrive solenoid valve. OK: Operating sound can be heard.
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Q.
Is the check result normal?
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Go to Step 4.
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Replace the A/T-ECU <4M4> or engine-A/T-ECU <6G7>.
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STEP 4. Hydraulic pressure test
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Measure the hydraulic pressure of the underdrive clutch when the selector lever is at the L range.
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OK: Refer to .
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Q.
Is the check result normal?
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Go to Step 7.
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Go to Step 5.
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STEP 5. A/T-ECU <4M4> or engine-A/T-ECU <6G7> replacement
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(1)Replace the A/T-ECU <4M4> or engine-A/T-ECU <6G7>.
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(2)Test drive the vehicle.
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(3)Verify that the condition described by the customer exists.
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Q.
Does a malfunction take place again?
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Go to Step 6.
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The inspection is complete.
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STEP 6. Valve body disassembly clean and assembly
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(1)Check the bolts for looseness and the O-ring, solenoid valve and valve body for damage. Replace the valve body assembly if the damages are thought to be irreparable.
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(2)Test drive the vehicle.
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(3)Verify that the condition described by the customer exists.
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Q.
Does a malfunction take place again?
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Go to Step 7.
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The inspection is complete.
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(1)If the damage is in the oil pump assembly, replace the oil pump assembly.
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(2)Test drive the vehicle.
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(3)Verify that the condition described by the customer exists.
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Q.
Is the check result normal?
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Go to Step 8.
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The inspection is complete.
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STEP 8. Underdrive clutch check
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(1)Check the facing for seizure and the piston seal ring for damage and interference with the retainer.
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(2)Test drive the vehicle.
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(3)Verify that the condition described by the customer exists.
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Q.
Is the check result normal?
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The inspection is complete.
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Repair or replace the underdrive clutch.
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