Inspection Procedure 1: Keyless Entry System Does Not Work: Diagnosis

Required Special Tools: 

• MB991223: Harness Set
• MB992006: Extra Fine Probe

1. STEP 1. ETACS-ECU coding data check 
   1. Use scan tool (M.U.T.-III) to read out the option coding information in ETACS-ECU (Refer to CODING REFERENCE TABLE ).
   2. Check if the "Keyless function" is "Enabled."

   Q: Is the check result normal? 

   • YES:  Go to Step 2.
   • NO:  Operate the scan tool (M.U.T.-III) to set the option coding "keyless" to "enabled," and check the trouble symptom.
2. STEP 2. Using scan tool (M.U.T.-III), diagnose the CAN bus line. 
   CAUTION: To prevent damage to scan tool (M.U.T.-III), always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool (M.U.T.-III).
   1. Connect scan tool (M.U.T.-III). Refer to HOW TO CONNECT THE SCAN TOOL (M.U.T.-III) ."
   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.

   Q: Is the CAN bus line found to be normal? 

   • YES:  Go to Step 3.
   • NO:  Repair the CAN bus line. (Refer to DIAGNOSIS .)
3. STEP 3. Using scan tool (M.U.T.-III), read the DTC. 

   Check that ETACS-ECU stores a DTC.

   Q: Is the DTC stored? 

   • YES:  Refer to DIAGNOSTIC TROUBLE CODE TABLE  .
   • NO:  Go to Step 4.
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

   Q: Is the check result normal? 

   • YES:  Go to Step 5.
   • NO:  Refer to MALFUNCTION OF ETACS-ECU POWER SUPPLY CIRCUIT .
5. STEP 5. Check the operation of the central door locking system. 

   Check that the central door locking system works normally.

   Q: Is the check result normal? 

   • YES:  Go to Step 6.
   • NO:  Refer to STANDARD FLOW OF DIAGNOSTIC TROUBLESHOOTING .
6. STEP 6. Using scan tool (M.U.T.-III), 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 name	Normal condition
     256	Dr door ajar switch	Close
     257	As door ajar switch	Close
     258	RR door ajar switch	Close
     259	RL door ajar switch	Close
     260	Trunk/gate trunk ajar switch	Close
     264	Handle lock switch	Key in → Key out

     OK: Normal conditions are displayed for all the items. 

   Q: Is the check result normal? 

   Normal conditions are displayed for all the items.:  Go to Step 7.

   Normal condition is not displayed for item No. 256.:  Refer to INSPECTION PROCEDURE 5: THE FRONT DOOR SWITCH (DRIVER'S SIDE) SIGNAL IS NOT RECEIVED .

   Normal condition is not displayed for item No. 257.:  Refer to INSPECTION PROCEDURE 6: THE FRONT DOOR SWITCH (PASSENGER'S SIDE) SIGNAL IS NOT RECEIVED .

   Normal condition is not displayed for item No. 258.:  Refer to INSPECTION PROCEDURE 7: THE REAR DOOR SWITCH (RH) SIGNAL IS NOT RECEIVED .

   Normal condition is not displayed for item No. 259.:  Refer to INSPECTION PROCEDURE 8: THE REAR DOOR SWITCH (LH) SIGNAL IS NOT RECEIVED .

   Normal condition is not displayed for item No. 260.:  Refer to INSPECTION PROCEDURE 9: THE LIFTGATE LOCK ACTUATOR < VEHICLES WITHOUT POWER LIFTGATE > OR LIFTGATE LATCH < VEHICLES WITH POWER LIFTGATE > SIGNAL IS NOT RECEIVED .

   Normal condition is not displayed for item No. 264.:  Refer to INSPECTION PROCEDURE 3: THE KEY REMINDER SWITCH SIGNAL IS NOT RECEIVED. < VEHICLES WITHOUT KOS > .

7. STEP 7. Check of short to power supply, short to ground, open circuit in SIGR, PWRC line between ETACS-ECU connector and receiver antenna connector. 

   Q: Is the check result normal? 

   • YES:  Go to Step 8.
   • NO:  Repair the connector(s) wiring harness.
8. STEP 8. Retest the system. 

   Check if the keyless entry system works normally.

   Q: Is the check result normal? 

   • YES:  Intermittent malfunction (Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTION ).
   • NO:  Replace receiver antenna (Refer to RECEIVER ANTENNA ) and turn ignition switch to ON and OFF. Then go to Step 9.
9. STEP 9. Retest the system. 

   Check if the keyless entry system works normally.

   Q: Is the check result normal? 

   • YES:  The diagnosis is complete.
   • NO:  Replace ETACS-ECU and register the ID codes (Refer to KEYLESS ENTRY SYSTEM INSPECTION  ).