Inspection Procedure 5: Auto-cruise Control cannot be Set.

COMMENTS ON TROUBLE SYMPTOM

The fail-safe function is probably cancelling auto-cruise control. In this case, checking the auto-cruise control system and diesel fuel system and A/T system diagnostic trouble codes. The M.U.T.-III can also be used to check if the circuits of each input switch are normal or not by checking the input switch codes.

note

Press the auto-cruise control switches one by one securely. Otherwise, the auto-cruise control system may not be started.

PROBABLE CAUSE

Malfunction of the auto-cruise control switch.
Malfunction of the stop lamp switch.
Malfunction of the clutch switch <M/T>.
Malfunction of the inhibitor switch <A/T>.
Malfunction of the diesel fuel system.
Malfunction of the A/T system <A/T>.
Malfunction of the A/T-ECU <A/T>.
Malfunction of the engine-ECU.

DIAGNOSIS

STEP 1. M.U.T.-III data list.

Item 136: "ON/OFF" (MAIN) switch
Item 137: "CANCEL" switch
Item 138: "COAST/SET" switch
Item 139: "ACC/RES" switch

(Refer to data list reference table

Q. Is the check result normal?

	Go to Step 2.

	Check the auto-cruise control switch system (Refer to - Diagnosis Code Procedures, Code No. P1564: Auto-cruise control switch system). Then go to Step 9.

STEP 2. M.U.T.-III data list.

Item 135: Stop lamp switch
Item 134: Brake switch

(Refer to data list reference table

Q. Is the check result normal?

	Go to Step 3 <M/T>.

	Go to Step 4 <A/T>.

	Check the auto-cruise control switch system (Refer to - Diagnosis Code Procedures, Code No. P1571: Stop lamp switch system). Then go to Step 9.

STEP 3. M.U.T.-III data list <M/T>.

Item 131: Clutch switch (Refer to data list reference table

Q. Is the check result normal?

	Go to Step 4.

	Check the clutch switch system (Refer to - Inspection Procedure 2). Then go to Step 9.

STEP 4. A/T system M.U.T.-III data list <A/T>.

Item 34: Inhibitor switch (Refer to GROUP 23A - Troubleshooting A/T, Data List Reference Table

Q. Is the check result normal?

	Go to Step 5.

	Check the inhibitor switch system [Refer to GROUP 23A - Troubleshooting <A/T>, Diagnosis Code Procedures, DTC P1770: Inhibitor switch system (Open Circuit) , DTC P1771: Inhibitor switch system (Short Circuit) ]. Then go to Step 9.

STEP 5. Check the diesel fuel system diagnosis code.

Refer to GROUP 13D - Troubleshooting, Diagnosis Function

Q. Is any diagnosis code set?

	Repair the diesel fuel system. (Refer to GROUP 13D - Troubleshooting, Inspection Chart for Diagnosis Trouble Code ). Then go to Step 9.

	Go to Step 7 <M/T>.

	Go to Step 6 <A/T>.

STEP 6. Check the A/T system diagnosis code <A/T>.

Refer to GROUP 23A - Troubleshooting <A/T>, Diagnosis Function

Q. Is any diagnosis code set?

	Repair the A/T system (Refer to GROUP 23A - Troubleshooting <A/T>, Diagnosis Code Chart ). Then go to Step 9.

	Go to Step 7.

STEP 7. Read the diagnosis code.

(1)Disconnect the negative (-) battery terminal, and erase the diagnosis code of the auto-cruise control system.

(2)Connect the negative (-) battery terminal.

(3)Turn the ignition switch to the "ON" position, and press the "ON/OFF" (MAIN) switch to turn the auto-cruise control system to ON.

(4)Read the diagnosis code of the auto-cruise control system.

Q. Is any diagnosis code set?

	Diagnose the auto-cruise control system (Refer to - Diagnosis Code Chart). Then go to Step 9.

	Go to Step 8.

STEP 8. Check the symptoms.

Q. Can auto-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 engine-ECU (Refer to GROUP 13D - Engine-ECU ). Then go to Step 9.

STEP 9. Check the symptoms.

Q. Can auto-cruise control be set?

	The procedure is complete.

	Return to Step 1.