Inspection Procedure 5: Hunting (Repeated Acceleration and Deceleration) Occurs at the Set Vehicle Speed.


COMMENTS ON TROUBLE SYMPTOM


The vehicle speed sensor or the diesel fuel system is suspected.

PROBABLE CAUSE



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).

Q. Is any diagnosis code set?
Repair the MPI system (Refer to GROUP 13A - Troubleshooting, Inspection Chart for Diagnosis Code ). 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). 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). 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.