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Inspection Procedure 5: Keyless entry system does not work.
 
 
cautionBefore replacing the ECU, ensure that the power supply circuit, the ground circuit and the communication circuit are normal.
 
 
 
 
TECHNICAL DESCRIPTION (COMMENT)
The lock/unlock signals from the transmitter are received by WCM, and then sent to ETACS-ECU from WCM. When ETACS-ECU receives signals from the key reminder switch and all the door switches, ETACS-ECU actuates the keyless entry system.
 
 
TROUBLESHOOTING HINTS
  • The key reminder switch may be defective
  • The door switches may be defective
  • The liftgate latch assembly may defective
  • The keyless entry transmitter may be defective
  • The WCM 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
STEP 1. Using scan tool MB991958, check for CAN bus the diagnostic trouble code.
(1)
cautionTo prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
Connect scan tool MB991958. Refer to "How to connect scan tool (M.U.T.-III) ."
(2) Turn the ignition switch to the "ON" position.
(3) Check whether the CAN bus lines related DTC is set.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
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 ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
Connect scan tool MB991958. Refer to "How to connect scan tool (M.U.T.-III) ."
(2) Turn the ignition switch to the "ON" position.
(3) Check whether the ETACS-ECU related DTC is set.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Is the DTC set?
Diagnose the ETACS-ECU. Refer to GROUP 54A, diagnostic trouble code chart .
Go to Step 3.
 
STEP 3. 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 4.
Refer to GROUP 54A - Malfunction of ETACS-ECU power supply circuit .
 
STEP 4. Verify the central door locking system.
Check that the central door locking system works normally.
Is the check result normal?
Go to Step 5.
Refer to GROUP 42A - Troubleshooting .
 
STEP 5. Using scan tool MB991958, check data list.
Check the signals related to the keyless entry system operation.
(1)
cautionTo prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
Connect scan tool MB991958. Refer to "How to connect the Scan Tool (M.U.T.-III) ."
(2) Turn the ignition switch to the "LOCK" (OFF) position.
(3) Check the ETACS data list.
  • Close the driver's door.
  • Close the passenger's door.
  • Close the RH-side rear door.
  • Close the LH-side rear door.
  • Close the liftgate.
  • Remove the ignition key from the ignition key cylinder.
 
Item No.Item nameNormal condition
Item 256Dr door ajar switchClose
Item 257As door ajar switchClose
Item 258RR door ajar switchClose
Item 259RL door ajar switchClose
Item 260Trunk/gate trunk ajar switchClose
Item 264Handle lock switchKey in → Key out
OK: Normal condition are displayed.
Are the check result normal?
<Normal conditions are displayed for all the items.> : Go to Step 6.
<Normal condition is not displayed for item No. 256.> : Refer to GROUP 54A, Inspection Procedure 5: ETACS-ECU does not receive any signal from the front door switch (LH) .
<Normal condition is not displayed for item No. 257.> : Refer to GROUP 54A, Inspection Procedure 6: ETACS-ECU does not receive any signal from the front door switch (RH) .
<Normal condition is not displayed for item No. 258.> : Refer to GROUP 54A, Inspection Procedure 8: ETACS-ECU does not receive any signal from the rear door switch (RH) .
<Normal condition is not displayed for item No. 259.> : Refer to GROUP 54A, Inspection Procedure 7: ETACS-ECU does not receive any signal from the rear door switch (LH) .
<Normal condition is not displayed for item No. 260.> : Refer to GROUP 54A - Inspection Procedure 10: The liftgate latch switch signal is not received .
<Normal condition is not displayed for item No. 264.> : Refer to GROUP 54A, Inspection Procedure 3: ETACS-ECU does not receive any signal from the key reminder switch. .
 
STEP 6. 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 WCM and register the ID codes (Refer to ).