Inspection Procedure 5
INSPECTION PROCEDURE 5: Cruise Control Cannot be Set ("COAST/SET" or "ACC/RES" Switch Operation is not Available).COMMENT
The fail-safe function is probably canceling cruise control system. In this case, checking the cruise control system, MFI system, TC-SST system
NOTE: Press the cruise control switches one by one securely. Otherwise, the cruise control system may not be started.
TROUBLESHOOTING HINTS (THE MOST LIKELY CAUSES FOR THIS CASE:)
- Malfunction of the CAN bus line system.
- Malfunction of the MFI system.
- Malfunction of the TC-SST system
- Malfunction of the shift lever system
- Malfunction of the cruise control switch.
- Malfunction of the stoplight switch.
- Malfunction of the clutch switch
- Malfunction of the TC-SST-ECU
- Malfunction of the shift lever ECU
- Malfunction of the ECM.
DIAGNOSIS
Required Special Tools:
- MB991958: Scan Tool (M.U.T.-III Sub Assembly)
- MB991824: V.C.I.
- MB991827: M.U.T.-III USB Cable
- MB991910: M.U.T.-III Main Harness A
CAUTION:
- If there is any problem in the CAN bus lines, an incorrect DTC may be set. Prior to this diagnosis, diagnose the CAN bus lines.
- Whenever the ECM is replaced, ensure that the CAN bus lines are normal.
STEP 1. Using scan tool MB991958, diagnose the CAN bus line.
CAUTION: To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
1. Connect scan tool MB991958 to the data link connector. Scan Tool Connecting
2. Turn the ignition switch to the "ON" position.
3. Diagnose the CAN bus line. How to Diagnose the CAN Bus Line
4. Turn the ignition switch to the "LOCK" (OFF) position.
5. Disconnect scan tool MB991958.
Q: Is the check result satisfactory?
YES : Go to Step 2
NO : Repair the CAN bus lines (Refer to Controller Area Network, Diagnosis-Can Bus Diagnostic Chart). Then go to Step 11.
STEP 2. Using scan tool MB991958, check for MFI system DTC.
1. Connect scan tool MB991958 to the data link connector. Scan Tool Connecting
2. Turn the ignition switch to the "ON" position.
3. Check for MFI system DTC (Refer to MFI, Diagnosis-Diagnostic Function). Diagnostic Function
4. Turn the ignition switch to the "LOCK" (OFF) position.
5. Disconnect scan tool MB991958.
Q: Is any DTC set?
YES : Diagnose the MFI system (Refer to MFI, Diagnosis-Diagnostic Trouble Code Chart). Diagnostic Trouble Code Descriptions Then go to Step 11.
NO : Go to Step 5
NO : Go to Step 3
STEP 3. Using scan tool MB991958, check for TC-SST system DTC
1. Connect scan tool MB991958 to the data link connector. Scan Tool Connecting
2. Turn the ignition switch to the "ON" position.
3. Check for TC-SST system DTC (Refer to Twin Clutch-Sportronic Shift Transmission (TC-SST), Diagnosis
4. Turn the ignition switch to the "LOCK" (OFF) position.
5. Disconnect scan tool MB991958.
Q: Is any DTC set?
YES : Diagnose the TC-SST system (Refer to Twin clutch-Sportronic Shift Transmission (TC-SST), Diagnosis
NO : Go to Step 4.
STEP 4. Using scan tool MB991958, check for shift lever system DTC
1. Connect scan tool MB991958 to the data link connector. Scan Tool Connecting
2. Turn the ignition switch to the "ON" position.
3. Check for shift lever system DTC (Refer to Twin Clutch-Sportronic Shift Transmission (TC-SST), Diagnosis
4. Turn the ignition switch to the "LOCK" (OFF) position.
5. Disconnect scan tool MB991958.
Q: Is any DTC set?
YES : Diagnose the shift lever system (Refer to Twin Clutch-Sportronic Shift Transmission (TC-SST), Diagnosis
NO : Go to Step 5.
STEP 5. Check for DTC. Read the cruise control system DTC (Refer to Engine and Emission Control).
Q: Is DTC set?
YES : Diagnose the cruise control system (Refer to Diagnostic Trouble Code Chart). Diagnostic Trouble Code Descriptions Then go to Step 11.
NO : Go to Step 6.
STEP 6. Using scan tool MB991958, check data list item 75: Cancel switch, item 86: Main switch, item 91: Resume switch and item 92: Set switch.
1. Connect scan tool MB991958 to the data link connector. Scan Tool Connecting
2. Turn the ignition switch to the "ON" position.
3. Set scan tool MB991958 to data reading mode for cruise control system. Reading Diagnostic Trouble Codes
- Item 75: Cancel switch.
- When "CANCEL" switch is at the "ON" position, the display on scan tool MB991958 should be "ON".
- When "CANCEL" switch is at the "OFF" position, the display on scan tool MB991958 should be "OFF".
- Item 86: Main switch.
- When "ON/OFF" switch is at the "ON" position, the display on scan tool MB991958 should be "ON".
- When "ON/OFF" switch is at the "OFF" position, the display on scan tool MB991958 should be "OFF".
- Item 91: Resume switch.
- When "ACC/RES" switch is at the "ON" position, the display on scan tool MB991958 should be "ON".
- When "ACC/RES" switch is at the "OFF" position, the display on scan tool MB991958 should be "OFF".
- Item 92: Set switch.
- When "COAST/SET" switch is at the "ON" position, the display on scan tool MB991958 should be "ON".
- When "COAST/SET" switch is at the "OFF" position, the display on scan tool MB991958 should be "OFF".
4. Turn the ignition switch to the "LOCK" (OFF) position.
5. Disconnect scan tool MB991958.
Q: Is the switch operating properly?
YES : Go to Step 7.
NO : Refer to Engine and Emission Control, Diagnostic Trouble Code Procedures-DTC 15: Cruise Control Switch System. Then go to Step 11. DTC 15
STEP 7. Using scan tool MB991958, check data list item 74: Brake light switch and item 89: Normally closed brake switch.
1. Connect scan tool MB991958 to the data link connector. Scan Tool Connecting
2. Turn the ignition switch to the "ON" position.
3. Set scan tool MB991958 to data reading mode for cruise control system. Reading Diagnostic Trouble Codes
- Item 74: Brake light switch.
- When the brake pedal is depressed, the display on scan tool MB991958 should be "ON".
- When the brake pedal is released, the display on scan tool MB991958 should be "OFF".
- Item 89: Normally closed brake switch.
- When the brake pedal is depressed, the display on scan tool MB991958 should be "ON".
- When the brake pedal is released, the display on scan tool MB991958 should be "OFF".
4. Turn the ignition switch to the "LOCK" (OFF) position.
5. Disconnect scan tool MB991958.
Q: Is the switch operating properly?
YES : Go to Step 8
YES : Go to Step 9
NO : Refer to Diagnostic Trouble Code Procedures-DTC 22: Stoplight Switch System. DTC 22 Then go to Step 11.
STEP 8. Using scan tool MB991958, check data list item 78: Clutch switch
1. Connect scan tool MB991958 to the data link connector. Scan Tool Connecting
2. Turn the ignition switch to the "ON" position.
3. Set scan tool MB991958 to data reading mode for cruise control system. Reading Diagnostic Trouble Codes
- Item 78: Clutch switch.
- When the clutch pedal is depressed, the display on scan tool MB991958 should be "ON".
- When the clutch pedal is released, the display on scan tool MB991958 should be "OFF".
4. Turn the ignition switch to the "LOCK" (OFF) position.
5. Disconnect scan tool MB991958.
Q: Is the switch operating properly?
YES : Go to Step 10.
NO : Refer to Symptom Procedures Inspection Procedure 2. Inspection Procedure 2 Then go to Step 11.
STEP 9. Using scan tool MB991958, check data list item 87: Neutral switch
1. Connect scan tool MB991958 to the data link connector. Scan Tool Connecting
2. Turn the ignition switch to the "ON" position.
3. Set scan tool MB991958 to data reading mode for cruise control system. Reading Diagnostic Trouble Codes
- Item 87: Neutral switch.
- When shift lever is at the "N", "P", "R" position, the display on scan tool MB991958 should be "ON".
- When shift lever is other than "N", "P", "R" position, the display on scan tool MB991958 should be "OFF".
4. Turn the ignition switch to the "LOCK" (OFF) position.
5. Disconnect scan tool MB991958.
Q: Is the switch operating properly?
YES : Go to Step 10.
NO : Refer to Symptom Procedures Inspection Procedure 3. Inspection Procedure 3 Then go to Step 11.
STEP 10. Check the symptoms.
Q: Can cruise control be set (Is the "COAST/SET" or "ACC/RES" switch operation available)?
YES : It can be assumed that this malfunction is intermittent (Refer to General (Body and Chassis), How to Use Troubleshooting/Inspection Service Points-How to Cope with Intermittent Malfunction).
NO : Replace the ECM [Refer to MFI, Engine Control Module (ECM)]. When the ECM is replaced, register the encrypted code (Refer to Wireless Control Module, Diagnosis-ID Code Registration Judgment Table). Then go to Step 11.
STEP 11. Check the symptoms.
Q: Can cruise control be set (Is the "COAST/SET" or "ACC/RES" switch operation available)?
YES : The procedure is complete.
NO : Return to Step 1.