Inspection Procedure 14: Keyless entry system does not work: Diagnosis

Required Special Tools: 

• MB992006: Extra fine probe
• MB991223: Harness set
• MB991958 Scan Tool (M.U.T.-III Sub Assembly)
  • MB991824: Vehicles Communication Interface (V.C.I.)
  • MB991827 M.U.T.-III USB Cable
  • MB991910 M.U.T.-III Main Harness A

1. STEP 1. Using scan tool MB991958, read CAN bus the diagnostic trouble code. 
   CAUTION: To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
   1. 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.

      Q: Is the DTC set? 

      1. YES:  Repair the CAN bus line (Refer to CAN BUS DIAGNOSTICS TABLE ).
      2. NO:  Go to Step 2.
         Fig 1: Connecting Special Tool MB991910 To Data Link Connector

         Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
2. STEP 2. Using scan tool MB991958, read the diagnostic trouble code. 
   CAUTION: To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
   1. 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 KOS-ECU related DTC is set.
   4. Turn the ignition switch to the "LOCK" (OFF) position.

      Q: Is the DTC set? 

      1. YES:  Diagnose the KOS-ECU. Refer to DIAGNOSTIC TROUBLE CODE PROCEDURES  .
      2. NO:  Go to Step 3.
         Fig 2: Connecting Special Tool MB991910 To Data Link Connector

         Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
3. STEP 3. Check the power supply system 

   With the ignition switch in the LOCK (OFF) position, check if the following function operates normally:

   • Headlights
   • Hazard warning light

     Q: Is the check result normal? 

     1. YES:  Go to Step 4.
     2. NO:  Refer to MALFUNCTION OF ETACS-ECU POWER SUPPLY CIRCUIT .
4. STEP 4. Verify the central door locking system. 

   Check that the central door locking system works normally.

   Q: Is the check result normal? 

   1. YES:  Go to Step 5.
   2. NO:  Refer to TROUBLESHOOTING .
5. STEP 5. Using scan tool MB991958, check data list. 

   Check the signals related to the keyless entry system operation.

   CAUTION: To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
   1. 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 trunk lid.
      • Remove the ignition key from the ignition key cylinder.
        Fig 3: Connecting Special Tool MB991910 To Data Link Connector

        Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
        ITEM NAME REFERENCE CHART
        
        

        Item No.	Item name	Normal condition
        Item 256	Dr door ajar switch	Close
        Item 257	As door ajar switch	Close
        Item 258	RR door ajar switch	Close
        Item 259	RL door ajar switch	Close
        Item 260	Trunk/gate trunk ajar switch	Close
        Item 264	Handle lock switch	Key in → Key out

        OK: Normal condition are displayed. 

        Q: Are the check result normal? 

        1. YES <Normal conditions are displayed for all the items.>:  Go to Step 6.
        2. NO <Normal condition is not displayed for item No. 256.>:  Refer to INSPECTION PROCEDURE 5: ETACS-ECU DOES NOT RECEIVE ANY SIGNAL FROM THE FRONT DOOR SWITCH (LH) .
        3. NO <Normal condition is not displayed for item No. 257.>:  Refer to INSPECTION PROCEDURE 6: ETACS-ECU DOES NOT RECEIVE ANY SIGNAL FROM THE FRONT DOOR SWITCH (RH) .
        4. NO <Normal condition is not displayed for item No. 258.>:  Refer to INSPECTION PROCEDURE 8: ETACS-ECU DOES NOT RECEIVE ANY SIGNAL FROM THE REAR DOOR SWITCH (RH) .
        5. NO <Normal condition is not displayed for item No. 259.>:  Refer to INSPECTION PROCEDURE 7: ETACS-ECU DOES NOT RECEIVE ANY SIGNAL FROM THE REAR DOOR SWITCH (LH) .
        6. NO <Normal condition is not displayed for item No. 260.>:  Refer to INSPECTION PROCEDURE 9: ETACS-ECU DOES NOT RECEIVE ANY SIGNAL FROM THE TRUNK LID LATCH. .
        7. NO <Normal condition is not displayed for item No. 264.>:  Refer to INSPECTION PROCEDURE 3: ETACS-ECU DOES NOT RECEIVE ANY SIGNAL FROM THE KEY REMINDER SWITCH .
6. STEP 6. Check KOS-ECU connector C-31 and receiver antenna module connector C-10 for loose, corroded or damaged terminals, or terminals pushed back in the connector. 

   Q: Are KOS-ECU connector C-31 and receiver antenna module connector C-10 in good condition? 

   1. YES:  Go to Step 7.
   2. NO:  Repair or replace the damaged component(s). Refer to HARNESS CONNECTOR INSPECTION . Check that the keyless entry system works normally.
7. STEP 7. Check the wiring harness between KOS-ECU connector C-31 (terminal Nos. 9, 10 and 13) and receiver antenna module connector C-10 (terminal Nos. 3, 4 and 5). 
   • Check the communication and earth lines for open circuit or short circuit.

     Q: Are the wiring harness between KOS-ECU connector C-31 (terminal Nos. 9, 10 and 13) and receiver antenna module connector C-10 (terminal Nos. 3, 4 and 5) in good condition? 

     1. YES:  Go to Step 8.
     2. NO:  The wiring harness may be damaged or the connector(s) may have loose, corroded or damaged terminals, or terminals pushed back in the connector. Repair the wiring harness as necessary. Check that the keyless entry system works normally.
8. STEP 8. Check with another registered keyless operation key. 

   Check that the keyless entry function can be used with another keyless operation key.

   Q: Can the keyless entry function be used? 

   1. YES:  Replace the keyless operation key concerned and register the ID codes (Refer to ID CODES REGISTRATION JUDGMENT TABLE  ).
   2. NO:  Go to Step 9.
9. STEP 9. Check of the troubles 

   Replace ETACS-ECU. After the replacement, perform the coding, and check that the keyless entry system operates normally.

   Q: Is the check result normal? 

   1. YES:  The diagnosis is complete.
   2. NO:  Replace KOS-ECU and register the ID codes (Refer to ID CODES REGISTRATION JUDGMENT TABLE  ).