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INSPECTION PROCEDURE A-4: Electric motor switch OFF position-linked door unlock function does not operate.
 
 
caution
  • Before replacing the ECU, ensure that the power supply circuit, the ground circuit and the communication circuit are normal.
 
 
 
 
COMMENTS ON TROUBLE SYMPTOM
If a door is not unlocked when the electric motor switch is turned to the LOCK position, a malfunction of the CAN bus line, electric motor switch or ETACS-ECU is suspected. Also, the electric motor switch OFF position-linked door unlock function may have been "Disabled" with the customization function.
 
 
PROBABLE CAUSES
  • Malfunction of CAN bus line
  • Malfunction of ETACS-ECU
  • Malfunction of electric motor switch
  • Damaged wiring harness and connectors
 
 
DIAGNOSIS
Required Special Tools:
  • MB991223: Harness Set
  • MB992006: Extra Fine Probe
STEP 1. Checking central door unlocking operation
Check that the central door locking system works normally.
Is the check result normal?
Go to Step 2.
Refer to Central Door Locking System Symptom Chart .
 
STEP 2. Check the customization function.
Check that "Always (Lock pos)" is set for "Auto door unlock by electric motor switch OFF position" with the customization function.
Is the check result normal?
Go to Step 3.
Set "Always (Lock pos)" for "Auto door unlock by electric motor switch OFF position" with the customization function (Refer to customization Function ).
 
STEP 3. Using scan tool (M.U.T.-IIISE), check CAN bus for diagnostic trouble code.
(1)
cautionTo prevent damage to scan tool (M.U.T.-IIISE), always turn the electric motor switch to the OFF position before connecting or disconnecting scan tool (M.U.T.-IIISE).
Connect scan tool (M.U.T.-IIISE). Refer to GROUP 54A, "How to connect scan tool (M.U.T.-IIISE) ."
(2) Turn the electric motor switch to the ON position.
(3) Check whether CAN bus lines related DTC is set.
(4) Turn the electric motor switch to the OFF position.
Is the DTC set?
Repair the CAN bus line (Refer to GROUP 54C, CAN bus diagnostics table ).
Go to Step 4.
 
STEP 4. Check the electric motor switch.
Check that the electric motor switch works normally.
Is the check result normal?
Go to Step 5.
Repair the electric motor switch (Refer to GROUP 42B - Electric Motor Switch Inspection ).
 
STEP 5. Retest the system.
Check that turning the electric motor switch to the OFF position unlocks tall doors.
Is the check result normal?
Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction ).
Replace the ETACS-ECU.