Ignition Key Cylinder Illumination Light Does Not Illuminate/Extinguish Normally < Vehicles With WCM >: Diagnosis

Required Special Tools: 

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

1. STEP 1. 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 ETACS-ECU related DTC is set.
   4. Turn the ignition switch to the "LOCK" (OFF) position.

   Q: Is the DTC set? 

   YES  : Diagnose the ETACS-ECU. Refer to ETACS-ECU .

   NO  : Go to Step 2.

   Fig 1: Connecting Special Tool To Data Link Connector

   Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
2. STEP 2. Using scan tool MB991958, check data list. 

   Use the ETACS-ECU data list to check the signals related to the ignition key cylinder illumination light function.

   • Turn the ignition switch to the "LOCK" (OFF) position.
   • Remove the ignition key from the ignition key cylinder.
   • Open the driver's door.
     NORMAL CONDITIONS CHART
     
     

     Item No.	Item name	Normal conditions
     Item 228	Dr door unlock	ON
     Item 254	IG voltage	0 V
     Item 256	Dr door ajar switch	Open
     Item 264	Handle lock switch	Key in → Key out
     Item 270	Dr door lock switch	Not lock
     Item 271	Dr door unlock switch	Unlock

   Q: Does scan tool MB991958 display the items "Dr door unlock", "Dr door ajar switch", and "Handle lock switch" as normal condition? 

   YES < Normal conditions are displayed for all the items. >  : Go to Step 3.

   NO < Normal condition is not displayed for item No. 228. >  : Troubleshoot the ETACS-ECU. Refer to DIAGNOSIS - INSPECTION PROCEDURE 4 "ETACS-ECU DOES NOT RECEIVE ANY SIGNAL FROM THE FRONT DOOR LOCK ACTUATOR" .

   NO < Normal condition is not displayed for item No. 254. >  : Troubleshoot the ETACS-ECU. Refer to DIAGNOSIS - INSPECTION PROCEDURE 2 "ETACS-ECU DOES NOT RECEIVE ANY SIGNAL FROM THE IGNITION SWITCH (IG1)" .

   NO < Normal condition is not displayed for item No. 256. >  : Troubleshoot the ETACS-ECU. Refer to DIAGNOSIS - INSPECTION PROCEDURE 6 "ETACS-ECU DOES NOT RECEIVE ANY SIGNAL FROM THE FRONT THE FRONT DOOR SWITCH (RH)" .

   NO < Normal condition is not displayed for item No. 264. >  : Troubleshoot the ETACS-ECU. Refer to DIAGNOSIS - INSPECTION PROCEDURE 3 "ETACS-ECU DOES NOT RECEIVE ANY SIGNAL FROM KEY REMINDER SWITCH" .

   NO < Normal condition is not displayed for item No. 270, 271. >  : Troubleshoot the ETACS-ECU. Refer to DIAGNOSIS - INSPECTION PROCEDURE 4 "ETACS-ECU DOES NOT RECEIVE ANY SIGNAL FROM FRONT DOOR LOCK ACTUATOR" .

3. STEP 3. Check key reminder switch connector C-211, ETACS-ECU connector C-315 for loose, corroded or damaged terminals, or terminals pushed back in the connector. 

   Q: Is key reminder switch connector C-211, ETACS-ECU connector C-315 in good condition? 

   YES  : Go to Step 4.

   NO  : Repair the damaged parts.

4. STEP 4. Check the wiring harness between key reminder switch connector C-211 (terminal No. 3, 5) and ETACS-ECU connector C-315 (terminal No. 13, 18). 
   • Check the input/output line for open circuit.

   Q: Is the check result normal? 

   YES  : Go to Step 5.

   NO  : Repair the wiring harness between key reminder switch connector C-211 and ETACS-ECU connector C-315.

5. STEP 5. Check of ignition key cylinder illumination light bulb. 

   Q: Is the ignition key cylinder illumination light bulb in good condition? 

   YES  : Go to Step 6.

   NO  : Replace the bulb of the ignition key cylinder illumination light.

6. STEP 6. Check the wiring harness between key reminder switch connector C-211 (terminal No. 7) and body ground. 
   • Check the ground line for open circuit.

   Q: Is the check result normal? 

   YES  : Go to Step 7.

   NO  : Repair the wiring harness between key reminder switch connector C-211 and body ground.

7. STEP 7. Retest the system. 

   Q: Does the ignition key cylinder illumination light illuminate/extinguish in good condition? 

   YES  : The trouble can be an intermittent malfunction (Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTION ).

   NO  : Replace the ETACS-ECU.