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INSPECTION PROCEDURE A-2: Central door locking system does not operate even when door lock switch of power window main switch operated.
 
 
caution
  • Before replacing the ECU, ensure that the power supply circuit, the ground circuit and the communication circuit are normal.
 
 
 
 
OPERATION
The ETACS-ECU controls the central door locking system, locking or unlocking all the doors by activating the central door lock relay (built in the ETACS-ECU). The ETACS-ECU uses input signals from the door lock switch, which is incorporated in the power window main switch.
 
 
COMMENTS ON TROUBLE SYMPTOM
If the central door locking system does not work at all, a malfunction of the door lock switch (built in the power window main switch) or ETACS-ECU is suspected.
 
 
PROBABLE CAUSES
  • Malfunction of the door lock switch (built in the power window main switch)
  • Malfunction of ETACS-ECU
  • Damaged wiring harness and connectors
 
 
DIAGNOSIS
Required Special Tools:
  • MB991223: Harness Set
  • MB992006: Extra Fine Probe
STEP 1. Checking central door locking system operation.
Check that the central door locking system works normally.
Is the check result normal?
Go to Step 2.
Refer to Inspection Procedure 1 "Central door locking system does not work at all ."
 
STEP 2. Central door lock switch check (built in the power window main switch).
Check that the central door lock switch works normally (Refer to Central Door Lock Switch Check ).
Is the check result normal?
Go to Step 3.
Replace the power window main switch.
 
STEP 3. Check of short to power supply, short to ground, and open circuit in D-LS, D-US line between ETACS-ECU connector and power window main switch connector.
Is the check result normal?
Go to Step 4.
Repair the connector(s) or wiring harness.
 
STEP 4. Check of open circuit in ground line between power window main switch connector and body ground.
Is the check result normal?
: Go to Step 5.
Repair the connector(s) or wiring harness.
 
STEP 5. Retest the system.
Check that the central door locking system works normally.
Is the check result normal?
: No action is necessary and testing is complete.
Replace ETACS-ECU.