Inspection Procedure 1

Inspection Procedure 1: When the Brake Pedal is Depressed, Cruise Control System is not Cancelled.

COMMENT
- Malfunction of CAN bus line.
- The stoplight switch circuit is suspected.

TROUBLESHOOTING HINTS (The most likely causes for this case:)
- Malfunction of CAN bus system.
- Damaged harness or connector.
- Malfunction of the stoplight switch.
- Malfunction of the ETACS-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 diagnostic trouble code may be set. Prior to this diagnosis, diagnose the CAN bus lines.
- Before replacing the ECU, ensure that the CAN bus lines is 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 Diagnostics Chart). Then go to Step 4.

STEP 2. Using scan tool MB991958, check the data list item 74: Brake light switch, 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 3.

NO : Refer to DTC 22: Stoplight switch system. DTC 22 Then go to Step 4.

STEP 3. Check the symptoms.

Q: When the brake pedal is depressed, cruise control system is cancelled?

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 Malfunctions).

NO : Replace the ECM [2.4L Engine] or ECM [3.0L Engine]. Then go to Step 4.

STEP 4. Check the symptoms.

Q: When the brake pedal is depressed, cruise control system is cancelled?

YES : The procedure is complete.

NO : Return to Step 1.