Inspection Procedure 2: Cruise Control cannot be Set (No Response SET - Switch is Pressed).

caution

If there is any problem in the CAN bus lines, an incorrect diagnosis code may be set. Prior to this diagnosis, diagnose the CAN bus lines (Refer to GROUP 54C - Troubleshooting ).
Whenever the ECU is replaced, ensure that the CAN bus lines are normal.
When the ACC/FCM-ECU is replaced, calibrate the radar (refer to ).

COMMENTS ON TROUBLE SYMPTOM

The conditions for initiating the ACC system may not be satisfied.

PROBABLE CAUSES

Malfunction of the CAN bus line
Damaged harness or connector.
Malfunction of the clock spring.
Malfunction of the cruise control switch.
Malfunction of the stop lamp switch.
Malfunction of the inhibitor switch.
Malfunction of the parking brake switch.
Malfunction of the engine system.
Malfunction of the ASTC system.
Malfunction of the A/T system.
Malfunction of the ACC/FCM-ECU.

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III CAN bus diagnostics.

Use M.U.T.-III to perform the CAN bus diagnosis.

Q. Is the check result normal?

	Go to Step 2.

	Repair the CAN bus lines (Refer to GROUP 54C - Troubleshooting ). On completion, go to Step 2.

STEP 2. Check whether the diagnosis code is set.

Q. Is diagnosis code set?

	Troubleshoot the ACC system diagnosis code (Refer to ).

	Go to Step 3.

STEP 3. Use M.U.T.-III to confirm a diagnosis code of other systems.

Check if the diagnosis code is set in the engine-ECU (Refer to GROUP 13B - Troubleshooting, Diagnosis Function) <6B3> or (Refer to GROUP 13C - Troubleshooting, Diagnosis Function) <4N1>.

Q. Is the diagnosis code set?

	Troubleshoot the engine-ECU diagnosis code (Refer to GROUP 13B - Troubleshooting, Inspection Chart for Diagnosis Code) <6B3> or (Refer to GROUP 13C - Troubleshooting, Inspection Chart for Diagnosis Code) <4N1>.

	Go to Step 4.

STEP 4. Use M.U.T.-III to confirm a diagnosis code of other systems.

Check if the diagnosis code is set in the ASTC-ECU (Refer to GROUP 35C - Troubleshooting <ASTC-ECU>, Diagnosis Function).

Q. Is the diagnosis code set?

	Troubleshoot the ASTC-ECU diagnosis code (Refer to GROUP 35C - Troubleshooting <ASTC-ECU>, Diagnosis Code Chart ).

	Go to Step 5.

STEP 5. Use M.U.T.-III to confirm a diagnosis code of other systems.

Check if the diagnosis code is set in the A/T-ECU (Refer to GROUP 23A - Troubleshooting <A/T>, Diagnosis Function).

Q. Is the diagnosis code set?

	Troubleshoot the A/T-ECU diagnosis code (Refer to GROUP 23A - Troubleshooting <A/T>, Diagnosis Code Chart).

	Go to Step 6.

STEP 6. Check the other symptom.

The system should be turned ON when the cruise control switch is operated.

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

	Go to Step 7 <6B3> or Step 8 <4N1>.

	Refer to GROUP 17 - Cruise Control system, Troubleshooting, Inspection Procedure 9: When the cruise control switch is operated, the system is not turned on.

STEP 7. Check the data list <6B3>.

Using M.U.T.-III, check the data list of MPI system (Refer to GROUP 17 - Cruise Control system, Troubleshooting, Data List Reference Table).

Item No. 75: CANCEL switch
Item No. 92: SET - switch

Q. Is the check result normal?

	Go to Step 10.

	Go to Step 9.

STEP 8. Check the data list <4N1>.

Using M.U.T.-III, check the data list of diesel fuel system (Refer to GROUP 17 - Cruise Control system, Troubleshooting, Data List Reference Table).

Item No. 137: CANCEL switch.
Item No. 138: SET - switch.

Q. Is the check result normal?

	Go to Step 10.

	Go to Step 9.

STEP 9. Check the cruise control switch.

Refer to

Q. Is the check result normal?

	Replace the engine-ECU (Refer to GROUP 13B - Engine-ECU) <6B3> or (Refer to GROUP 13C - Engine-ECU) <4N1>.

	Replace the cruise control switch (Refer to ).

STEP 10. Check the symptom.

(1)Drive the vehicle for approx. 3 minutes.

Q. Can cruise control be set?

	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 ACC/FCM-ECU (Refer to ).