Inspection Procedure 4

The "SECURITY" Indicator Light does not Illuminate.

The Security Indicator Circuit:

Connectors:

CIRCUIT OPERATION
If the requirements for starting the engine are not satisfied, the immobilizer-ECU flashes the "SECURITY" indicator for 30 seconds.

TECHNICAL DESCRIPTION (COMMENT)
There may be burned out bulb of the "SECURITY" indicator light or a malfunction of the combination meter (printed-circuit board) or immobilizer-ECU.

NOTE: The "SECURITY" indicator light is shared by the theft-alarm system. If a problem can not be resolved, observe the theft-alarm system troubleshooting.

TROUBLESHOOTING HINTS
- Burned out bulb of "SECURITY" indicator light
- Malfunction of combination meter (printed-circuit board)
- Malfunction of immobilizer-ECU
- Damaged harness wires or connectors

DIAGNOSIS

Required Special Tools:
- MB991223: Harness Set
- MB991502: Scan Tool (MUT-II)




STEP 1. Check the "SECURITY" indicator light circuit of immobilizer-ECU connector C-79.
1. Remove the immobilizer-ECU and measure at the harness side.
2. Connect terminal 9 to the ground.
3. Ignition switch "ON" position.

Q: Is the only "SECURITY" indicator light illuminate? (other indicator lights are good condition)

YES: Replace the immobilizer-ECU. Then register the password (secret code) and encrypted code.

NO: Go to Step 2.

STEP 2. Check the "SECURITY" Indicator light
1. Remove the combination meter and remove the "SECURITY" indicator light bulb.
2. Check the bulb.

Q: Is the "SECURITY" indicator light damaged?

YES: Replace it.

NO: Go to Step 3.




STEP 3. Check the combination meter connector C-42 for damage.

Q: Is the combination meter connector C-42 damaged?

YES: Repair or replace them. Refer to Harness Connector Inspection. Confirm that scan tool MB991502 communicates normally.

NO: Go to Step 4.







STEP 4. Check the harness wires between immobilizer ECU connector C-79 and combination meter connector C-42.

Q: Are immobilizer-ECU connector C-79 and combination meter connector C-42 damaged?

YES: Repair or replace them. Refer to Harness Connector Inspection.

NO: Repair the combination meter (printed-circuit board). Then Go to step 5.

STEP 5. Recheck for malfunction.

Q: Is a malfunction eliminated?

YES: This diagnosis is complete. (If no malfunctions are not found in all steps, an intermittent malfunction is suspected. Refer to How to Use Troubleshooting/Inspection Service Point.)

NO: Go to Step 1.