Inspection Procedure 1

INSPECTION Procedure 1: When the Brake Pedal is Depressed, Cruise Control 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.

DIAGNOSTIC PROCEDURE

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 (DTC) may be set. Prior to this diagnosis, diagnose the CAN bus lines.

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.
2. Turn the ignition switch to the "ON" position.
3. Diagnose the CAN bus line

Q: Is the check result satisfactory?

YES : Go to Step 2

NO : Repair the CAN bus lines. Then go to Step 4.

STEP 2. 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.
2. Turn the ignition switch to the "ON" position.
3. Set scan tool MB991958 to data reading mode for cruise control system.
- 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".

Q: Is the switch operating properly?

YES : Go to Step 3

NO : Repair the stoplight switch system. Then go to Step 4.

STEP 3. Check the symptoms.

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

YES : It can be assumed that this malfunction is intermittent.

NO : Replace the ECM. When the ECM is replaced, register the encrypted code. Then go to Step 4.

STEP 4. Check the symptoms.

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

YES : The procedure is complete.

NO : Return to Step 1.