Inspection Procedure 6: Hunting (Repeated Acceleration and Deceleration) Occurs at the Set Vehicle Speed. <M/T>


COMMENTS ON TROUBLE SYMPTOM


The vehicle speed sensor or the throttle body is suspected.

PROBABLE CAUSES



DIAGNOSIS PROCEDURE

STEP 1. Check the MPI system diagnosis code.
Using M.U.T.-III, perform MPI system diagnosis code (Refer to GROUP 13A - Troubleshooting, Diagnosis Function <4B1>, GROUP 13C - Troubleshooting, Diagnosis Function <4J1>)).

Q. Is any diagnosis code set?
Repair the MPI system (Refer to GROUP 13A - Troubleshooting, Inspection Chart for Diagnosis Code <4B1>, GROUP 13C - Troubleshooting, Inspection Chart for Diagnosis Code <4J1>). Then go to Step 4.
Go to Step 2.

STEP 2. Check the data list.
Using M.U.T.-III, check the data list (Refer to data list reference table ).

  • Item 04: Vehicle speed signal

Q. Is the check result normal?
Go to Step 3.
Replace the engine-ECU (Refer to GROUP 13A - Engine-ECU <4B1>, GROUP 13C - Engine-ECU <4J1>). Then go to Step 4.

STEP 3. Check the symptom.

Q. Does a hunting occur?
Replace the engine-ECU (Refer to GROUP 13A - Engine-ECU <4B1>, GROUP 13C - Engine-ECU <4J1>). Then go to Step 4.
It can be assumed that this malfunction is intermittent (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points, How to Cope with Intermittent Malfunction ).

STEP 4. Check the symptom.

Q. Does a hunting occur?
Return to Step 1.
The procedure is complete.