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Inspection Procedure 5: No door will be locked or unlocked by operating a lock/unlock switch on any door.
 
 
cautionBefore replacing the ECU, ensure that the power supply circuit, the ground circuit and the communication circuit are normal.
 
 
 
 
TROUBLESHOOTING HINTS
  • Malfunction of the CAN bus lines
  • Malfunction of the central door locking system
  • Malfunction of the keyless operation key
  • Damaged wiring harness and connectors
  • Malfunction of the KOS-ECU
  • Function setting error or no setting with a customization
 
 
DIAGNOSIS
STEP 1. Using scan tool MB991958, read CAN bus diagnostic trouble code.
(1)
cautionTo prevent damage to scan tool MB991958, always turn the power supply mode of the engine switch to the OFF position before connecting or disconnecting scan tool MB991958.
Connect scan tool MB991958. Refer to "How to connect scan too (M.U.T.-III) ."
(2) Turn the power supply mode of the engine switch to ON.
(3) Check whether the CAN bus lines related DTC is set.
(4) Turn the power supply mode of the engine switch to OFF.
Is the DTC set?
Repair the CAN bus line (Refer to GROUP 54C, CAN bus diagnostics table ).
Go to Step 2.
 
STEP 2. Using scan tool MB991958, read the diagnostic trouble code.
(1)
cautionTo prevent damage to scan tool MB991958, always turn the power supply mode of the engine switch to the OFF position before connecting or disconnecting scan tool MB991958.
Connect scan tool MB991958. Refer to "How to connect scan too (M.U.T.-III) ."
(2) Turn the power supply mode of the engine switch to ON.
(3) Check whether the KOS-ECU related DTC is set.
(4) Turn the power supply mode of the engine switch to OFF.
Is the DTC set?
Diagnose the KOS-ECU. Refer to diagnostic trouble code chart .
Go to Step 3.
 
STEP 3. Check the central door locking operation
Check that the central door locking system works normally.
Is the check result normal?
Go to Step 4.
Perform troubleshooting for the central door locking system (Refer to GROUP 42A - Door - Troubleshooting ).
 
STEP 4. Check the customization function.
Check that either of the followings other than "ENG strt enable" or "Both disabled" are set for "KOS feature" with the customization function.
  • Both enable
  • Door Entry enable
Is the check result normal??
Go to Step 5.
Set either of the followings other than "ENG strt enable" or "Both disabled" for "KOS feature" with the customization function (Refer to ).
 
STEP 5. Check with another registered keyless operation key.
Does the IG knob turn? (Is the keyless operation key recognized?)
Replace the keyless operation key with which the IG knob does not turn (no recognition) and register the ID codes (Refer to ).
Go to Step 6.
 
STEP 6. Check of the troubles
Operate the lock/unlock switch and check that the door can be locked and unlocked.
Is the check result normal?
The diagnosis is complete.
Replace KOS-ECU and register the ID codes (Refer to ).