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Inspection Procedure 1: Keyless entry system does not work.
 
 
cautionWhenever the ECU is replaced, ensure that the input and output signal circuits are normal.
 
 
 
 
 
TECHNICAL DESCRIPTION (COMMENT)
The lock/unlock signals from the transmitter are received by receiver antenna, and then sent to ETACS-ECU from receiver antenna. When ETACS-ECU receives signals from the key reminder switch, all the door switches and the liftgate latch, ETACS-ECU actuates the keyless entry system.
 
 
 
TROUBLESHOOTING HINTS
  • The key reminder switch may be defective
  • The door switches may be defective
  • The liftgate switch may be defective
  • The transmitter may be defective
  • Transmitter battery discharged
  • The driver's door lock actuator may be defective
  • The receiver antenna may be defective
  • The ETACS-ECU may be defective
  • The wiring harness or connectors may have loose, corroded, or damaged terminals, or terminals pushed back in the connector
  • Option coding information
 
 
 
 
DIAGNOSIS
Required Special Tools:
  • MB991223: Harness Set
  • MB992006: Extra Fine Probe
STEP 1. ETACS-ECU coding data check
(1) Use scan tool (M.U.T-IIISE) to read out the option coding information in ETACS-ECU.
(2) Check if the "Keyless function" is "Enabled."
Is the check result normal?
Go to Step 2.
Operate the scan tool (M.U.T-IIISE) to set the option coding "keyless" to "enabled, " and check the trouble symptom.
 
STEP 2. Using scan tool (M.U.T-IIISE), diagnose the CAN bus line.
(1)
cautionTo prevent damage to scan tool (M.U.T.-IIISE), always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool (M.U.T.-IIISE).
Connect scan tool (M.U.T-IIISE). Refer to GROUP 42B, "How to connect the Scan Tool (M.U.T-IIISE) ."
(2) Turn the ignition switch to the "ON" position.
(3) Diagnose the CAN bus line.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Is the CAN bus line found to be normal?
Go to Step 3.
Repair the CAN bus line. (Refer to GROUP 54C, Diagnosis ).
 
STEP 3. Using scan tool (M.U.T.-IIISE), read the DTC.
Check whether the ETACS-ECU sets a DTC.
Is the DTC set?
Refer to DTC chart .
Go to Step 4.
 
STEP 4. Check the power supply system
With the ignition switch in the "LOCK" (OFF) position, check if the following function operates normally:
  • Hazard warning light
Is the check result normal?
Go to Step 5.
Refer to GROUP 54A, Malfunction of ETACS-ECU power supply circuit .
 
STEP 5. Check the operation of the central door locking system.
Check that the central door locking system works normally.
Is the check result normal?
Go to Step 6.
Refer to GROUP 42A, Troubleshooting .
 
STEP 6. Using scan tool (M.U.T.-IIISE), check data list.
Check for the signals related to the keyless entry system operation.
  • Turn the ignition switch to the "LOCK" (OFF) position.
  • Remove the ignition key from the ignition key cylinder.
  • Close the driver's door.
  • Close the front passenger's doors.
  • Close the RH-side rear door.
  • Close the LH-side rear door.
  • Close the liftgate
 
Item No.Item nameNormal condition
81Dr door ajar switchClose
82As door ajar switchClose
83RR door ajar switchClose
84RL door ajar switchClose
85Trunk/gate trunk ajar switchClose
88Handle lock switchKey in → Key out
Item No.Item nameNormal condition
81Dr door ajar switchClose
82As door ajar switchClose
83RR door ajar switchClose
84RL door ajar switchClose
85Trunk/gate trunk ajar switchClose
88Handle lock switchKey in → Key out
OK: Normal conditions are displayed for all the items.
Is the check result normal?
: Go to Step 7.
: Refer to GROUP 54A, Inspection Procedure 5: "The front door switch (driver’s side) signal is not received ."
: Refer to GROUP 54A, Inspection Procedure 6: "The front door switch (passenger’s side) signal is not received ."
: Refer to GROUP 54A, Inspection Procedure 7: "The rear door switch (RH) signal is not received ."
: Refer to GROUP 54A, Inspection Procedure 8: "The rear door switch (LH) signal is not received ."
: Refer to GROUP 54A, Inspection Procedure 9: "The liftgate lock actuator signal is not received ."
: Refer to GROUP 54A, Inspection Procedure 3: "The key reminder switch signal is not received ."
 
STEP 7. Check whether the transmitter battery is discharged.
The switch indicator should illuminate when you press the lock/unlock switch in the ignition key.
Does the switch indicator illuminate when you press the switch?
: Go to Step 8
Replace the transmitter battery.
 
STEP 8. Replace the ignition key, and then check whether the DTC is set again.
Check if the keyless entry system works normally.
Is the check result normal?
: The diagnosis is complete.
Go to Step 9
 
STEP 9. Check of short to power supply, short to ground, open circuit in WRA, WUHF, WPC, WGN line between ETACS-ECU connector and receiver antenna connector.
Is the check result normal?
: Go to Step 10.
Repair the connector(s) wiring harness.
 
STEP 10. Retest the system.
Check if the keyless entry system works normally.
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 receiver antenna (Refer to GROUP 54A, Receiver antenna ) and turn ignition switch to ON and OFF. Then go to Step 11.
 
STEP 11. Retest the system.
Check if the keyless entry system works normally.
Is the check result normal?
The diagnosis is complete.
Replace ETACS-ECU and register the ID codes (Refer to ).