Inspection Procedure
7: Shift Shock when Shifting from N to D 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 D range while the engine is idling, the cause is probably abnormal underdrive clutch
pressure or a malfunction of the underdrive clutch, valve body or accelerator pedal position
sensor.
PROBABLE CAUSES
- Malfunction of underdrive solenoid valve
- Malfunction of input shaft speed sensor
- Abnormal underdrive clutch pressure
- Malfunction of accelerator pedal position sensor
- Malfunction of the underdrive clutch
- 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 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 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 data list
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Item 13: Underdrive 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 4.
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Replace the A/T-ECU <4M4> or engine-A/T-ECU <6G7>.
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STEP 4. 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 6.
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Go to Step 5.
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STEP 5. Hydraulic pressure test
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Measure the hydraulic pressure for underdrive clutch when the selector lever is shifted
from N to D 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 9.
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Go to Step 8.
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STEP 6. Check when shift shock occurs.
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Q.
Does the shift shock always occur?
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Go to Step 8.
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Go to Step 7.
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STEP 7. 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 8.
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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 8. 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 9.
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The inspection is complete.
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STEP 9. Underdrive clutch 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 underdrive clutch.
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