Ignition Key Cylinder Illumination Light does not Illuminate/Extinguish Normally. [Vehicles With KOS]
Ignition key cylinder illumination light does not illuminate/extinguish normally.CAUTION: Whenever the ECU is replaced, ensure that the input and output signal circuits are normal.
Ignition Key Cylinder Illumination Light Circuit Part 1:
Ignition Key Cylinder Illumination Light Circuit Part 2:
OPERATION
The ETACS-ECU operates this function in accordance with the input signals below.
- Ignition switch (IG1)
- Key reminder switch
- Steering lock (CAN information)
- Driver's door switch
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
- CAN bus line may be defective
- The key reminder switch may be defective
- The driver's door switch 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, diagnose the CAN bus line.
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 "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 2.
NO: Repair the CAN bus line (Refer to Information Bus, Diagnosis).
STEP 2. Using scan tool MB991958, check for any diagnostic trouble code.
Check if DTC is set to the KOS-ECU
1. Turn the ignition switch to the "ON" position.
2. Check whether the KOS or WCM related DTC is set.
3. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the DTC set?
YES
YES
NO: Go to Step 3.
STEP 3. 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
NO
NO
NO
NO
STEP 4. 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 5.
NO: Repair the damaged parts.
STEP 5. 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 6.
NO: Repair the wiring harness between key reminder switch connector C-211 and ETACS-ECU connector C-315.
STEP 6. Check of ignition key cylinder illumination light bulb.
Q: Is the ignition key cylinder illumination light bulb in good condition?
YES: Go to Step 7.
NO: Replace the bulb of the ignition key cylinder illumination light.
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 use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction).
NO: Replace the ETACS-ECU.