Inspection Procedure
8: Shift Shock when Shifting from N to R and Long Delay
COMMENTS ON TROUBLE SYMPTOM
If abnormal shock or delay of two seconds or more occurs when the selector lever is shifted
from N to R range while the engine is idling, the cause is probably abnormal pressure in reverse
clutch and low-reverse clutch or a malfunction of the reverse clutch, low-reverse brake, valve
body or accelerator pedal position sensor.
PROBABLE CAUSES
- Malfunction of low-reverse solenoid valve
- Malfunction of input shaft speed sensor
- Malfunction of the inhibitor switch
- Abnormal reverse clutch pressure
- Abnormal low-reverse brake pressure
- Malfunction of accelerator pedal position sensor
- Malfunction of the reverse clutch
- Malfunction of low-reverse brake
- Malfunction of valve body
- 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 1: 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. M.U.T.-III data list
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Item 5: Input shaft speed sensor (Refer to data list reference table  ).
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Q.
Is the check result normal?
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Go to Step 3.
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Refer to diagnosis code P1766: Input shaft speed sensor system .
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STEP 3. 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 4.
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STEP 4. M.U.T.-III data list
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Item 12: Low-reverse solenoid valve duty ratio (Refer to data list reference table ).
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Q.
Is the check result normal?
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Go to Step 5.
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Replace the A/T-ECU <4M4> or engine-A/T-ECU <6G7>.
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STEP 5. Check when shift shock occurs.
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Q.
Does the shift shock occur when the vehicle starts moving?
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Go to Step 7.
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Go to Step 6.
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STEP 6. Hydraulic pressure test
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Measure the hydraulic pressure for reverse clutch and low-reverse clutch when the selector
lever is shifted from N to R 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 10.
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Go to Step 9.
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STEP 7. Check when shift shock occurs.
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Q.
Does the shift shock always occur?
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Go to Step 9.
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Go to Step 8.
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STEP 8. M.U.T.-III data list
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Item 2: Accelerator pedal position sensor (Refer to data list reference table ).
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Q.
Is the check result normal?
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Go to Step 9.
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Check the accelerator pedal position sensor system (Refer to GROUP 13A - Troubleshooting,
Inspection Chart For Diagnosis Code <6G72> or GROUP
13B - Troubleshooting, Inspection Chart For Diagnosis Code <6G75> or
GROUP 13D - Troubleshooting, Inspection Chart For Diagnosis Code <4M41>).
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STEP 9. 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 10.
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The inspection is complete.
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STEP 10. 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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