Inspection Procedure 4: Does not move backward
COMMENTS ON TROUBLE SYMPTOM
If the vehicle does not move backward when the selector lever is shifted to R range while the engine is idling, the cause is probably abnormal pressure of the reverse clutch and low-reverse brake or a malfunction of the reverse clutch, low-reverse brake, or valve body.
PROBABLE CAUSES
- Abnormal reverse clutch pressure
- Abnormal low-reverse brake pressure
- Malfunction of low-reverse solenoid valve
- Malfunction of the reverse clutch
- Malfunction of low-reverse brake
- Malfunction of valve body
- Malfunction of the engine-A/T-ECU
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STEP 1. M.U.T.-III actuator test
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Item 01: Low-reverse 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 low-reverse solenoid valve.
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STEP 2. Hydraulic pressure test
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Measure the hydraulic pressure for reverse clutch and low-reverse brake when the selector lever is at the R range (Refer to ).
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OK: Refer to .
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Q.
Is the check result normal?
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Go to Step 5.
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Go to Step 3.
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STEP 3. Engine-A/T-ECU replacement
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(1)Replace the engine-A/T-ECU.
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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 4.
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The inspection is complete.
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STEP 4. Valve body disassembly clean and assembly
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(1)Check the bolts for looseness and the O-ring, solenoid valves, springs 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 5.
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The inspection is complete.
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STEP 5. Reverse clutch and low-reverse brake check
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Check the facing for seizure and the piston seal ring for damage and interference with the retainer.
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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 reverse clutch and low-reverse brake.
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