Inspection Procedure 1 [Vehicles With WCM]

Inspection Procedure 1: Ignition key cylinder illumination light does not illuminate/extinguish normally. [vehicles with WCM]

CAUTION:
Whenever the ECU is replaced, ensure that the input and output signal circuits are normal.














OPERATION

The ETACS-ECU operates this function in accordance with the input signals below.

- Ignition switch (IG1)
- Key reminder switch
- Driver's door switch
- Driver's door lock actuator

TECHNICAL DESCRIPTION (COMMENT)

If this function does not work normally, these input signal circuit(s), the ignition key cylinder illumination light or the ETACS-ECU may be defective.

TROUBLESHOOTING HINTS

- The key reminder switch may be defective
- The driver's door switch may be defective
- The driver's door lock actuator may be defective
- The ignition key cylinder illumination light bulb 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

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.





(1)
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 tool (M.U.T.-III) Reading and Clearing Diagnostic Trouble Codes."
(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 Electronic Time and Alarm Control System (ETACS).

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.





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. Inspection Procedure 4.
NO [Normal condition is not displayed for item No. 254.] : Troubleshoot the ETACS-ECU. Inspection Procedure 2.
NO [Normal condition is not displayed for item No. 256.] : Troubleshoot the ETACS-ECU. Inspection Procedure 6.
NO [Normal condition is not displayed for item No. 264.] : Troubleshoot the ETACS-ECU. Inspection Procedure 3.
NO [Normal condition is not displayed for item No. 270, 271.] : Troubleshoot the ETACS-ECU. Inspection Procedure 4.
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 How to Cope With Intermittent Malfunctions).
NO Replace the ETACS-ECU.