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Inspection Procedure A-12: Alarm does not sound normally when power liftgate works automatically.
 
 
cautionBefore replacing the ECU, ensure that the input and output signal circuits are normal.
 
 
 
 
COMMENTS ON TROUBLE SYMPTOM
The wiring harness or its connector(s) between the power liftgate tone alarm and the power liftgate control unit, the power liftgate tone alarm itself or the power liftgate control unit itself may be defective.
 
 
PROBABLE CAUSES
  • Damaged power liftgate tone alarm
  • Damaged power liftgate control unit
  • Damaged wiring harness and connectors
 
 
DIAGNOSIS
Required Special Tools:
  • MB991223: Harness Set
  • MB992006: Extra Fine Probe
STEP 1. Using scan tool (M.U.T.-IIISE), read the actuator test.
Perform the actuator test, and check that the power liftgate tone alarm sounds.
  • No.4: Alarm buzzer
Is the check result normal?
Go to Step 6.
Go to Step 2.
 
STEP 2. Power liftgate tone alarm inspection
Check the power liftgate tone alarm. Refer to .
Is the check result normal?
Go to Step 3.
Replace the power liftgate tone alarm.
 
STEP 3. Resistance measurement at power liftgate tone alarm connector
(1) Disconnect the connector, and measure at the wiring harness side.
(2) Measure the resistance between tone alarm connector and body ground.
OK: 10 Ω or less
Is the check result normal?
Go to Step 5.
Go to Step 4.
 
STEP 4. Check of open circuit in ground line between power liftgate tone alarm connector and body ground.
Is the check result normal?
Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction .)
Repair the connector(s) or wiring harness.
 
STEP 5. Check of short to power supply, short to ground, and open circuit in BZ+ line between power liftgate control unit connector and power liftgate tone alarm connector.
Is the check result normal?
Go to Step 6.
Repair the connector(s) or wiring harness.
 
STEP 6. Check of the troubles
Check whether the warning operates normally when the power liftgate is operated.
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 power liftgate control unit.