Inspection Procedure 9: When The Cruise Control Switch is Operated, The System is not Turned ON.


This circuit judges the signals of each switches (speed limiter ON/OFF, cruise control ON/OFF, CANCEL, SET - and RES +) of the cruise control switches. The engine-ECU detects the state of the cruise control switches by sensing the voltages shown below.


The M.U.T.-III can also be used to check if the circuits of each input switches are normal or not by checking the data list.
note Press the cruise control switches one by one securely. Otherwise, the cruise control system may not be started.



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>).
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 75: CANCEL switch
  • Item 86: Cruise control ON/OFF switch
  • Item 91: RES + switch
  • Item 92: SET - switch
  • Item 174: Speed limiter main switch

Q. Is the check result normal?

Go to Step 4.
Go to Step 3.

STEP 3. Check the cruise control switches.

Refer to .

Q. Is the check result normal?

Go to Step 4.
Replace the cruise control switches (Refer to ).

STEP 4. Check the symptom.

Q. Is the system turned on by operating the cruise control switch?

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 ).
Replace the engine-ECU (Refer to GROUP 13A - Engine-ECU <4B1>, GROUP 13C - Engine-ECU <4J1>).