Symptom Procedures: 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)
- 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.
- Connect scan tool MB991958. Refer to "HOW TO CONNECT SCAN TOO (M.U.T.-III) ".
- Turn the ignition switch to the "ON" position.
- Check whether the ETACS-ECU related DTC is set.
- 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.
- 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.ITEM 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 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 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 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 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 INSPECTION PROCEDURE 4 "ETACS-ECU DOES NOT RECEIVE ANY SIGNAL FROM FRONT DOOR LOCK ACTUATOR" .
- 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.
- 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.
- 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.
- 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.
- 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 MALFUNCTIONS ).
NO: Replace the ETACS-ECU.