Inspection Procedure N-1
Security Indicator Light Circuit:
Connectors:
CIRCUIT OPERATION
The theft-alarm system will be armed after the doors are locked and then the "SECURITY" indicator light has illuminated for approximately 18 seconds.
TECHNICAL DESCRIPTION (COMMENT)
The ETACS-ECU arms the theft-alarm system according to the input signals from the following switches:
- Ignition key reminder switch
- Driver's and passenger's door switch
- Driver's and passenger's door lock key cylinder switch
- Driver's and passenger's door lock actuator switch
- Hood switch
- Liftgate latch switch
- Liftgate lock key cylinder switch
- Transmitter
If the theft-alarm system is armed normally, the relevant input signal circuit(s), the "SECURITY" indicator light or the ETACS-ECU may be defective.
TROUBLESHOOTING HINTS
- Malfunction of the combination meter ("SECURITY" indicator light bulb or printed-circuit board)
- Malfunction of the ignition key reminder switch
- Malfunction of the driver's or passenger's door switch
- Malfunction of the driver's or passenger's door lock key cylinder switch
- Malfunction of the driver's or passenger's door lock actuator switch
- Malfunction of the hood switch
- Malfunction of the liftgate latch switch
- Malfunction of the liftgate lock key cylinder switch
- Malfunction of the transmitter
- Malfunction of the ETACS-ECU
- Damaged harness wires or connectors
DIAGNOSIS
Required Special Tools:
MB991223: Test Harness Set
MB991502: Scan Tool (MUT-II)
MB991529: Diagnostic Trouble Code Check Harness
STEP 1. Check the ETACS-ECU power supply circuit.
Do all of the following functions work when the ignition switch is turned to "LOCK" (OFF) position?
- Ignition key reminder tone alarm function
- Light reminder tone alarm function
- Central door locking system
- Hazard warning light
- Dome light dimming function
If no functions work normally, check the ETACS-ECU battery circuit. Refer to Inspection Procedure P-1.
P - Charts
If any of the functions work, go to Step 2.
STEP 2. Check the "SECURITY" indicator circuit at the ETACS-ECU connector C-112.
1. Disconnect the ETACS-ECU connector C-112 and measure at the harness side.
2. Connect terminal 39 to the ground.
- The "SECURITY" indicator light should illuminate.
If the "SECURITY" indicator light does not illuminate, go to Step 3.
If the "SECURITY" indicator tight illuminate, go to Step 8.
STEP 3. Check the "SECURITY" indicator light bulb.
If the "SECURITY" indicator bulb has been burned out, replace it.
The "SECURITY" indicator light should illuminate, and the theft-alarm system should be armed normally.
If the "SECURITY" indicator light bulb is in good condition, go to Step 4.
STEP 4. Check the combination meter (printed-circuit board).
1. Remove the combination meter.
2. Remove the "SECURITY" indicator light bulb. Then measure the resistance between the bulb terminals.
3. Install the bulb to the combination meter, and then measure the resistance between connector C-42 terminals 30 and 31. The resistance reading at this time should be much the same as the resistance measured at Step (2).
If the two resistance values are extremely different each other, repair or replace the combination meter (printed-circuit board). The "SECURITY" indicator light should illuminate, and the theft-alarm system should be armed normally.
If the two resistance values are much the same, go to Step 5.
STEP 5. Check the combination meter connector C-42 and ETACS-ECU connector C-112 for damage.
If the combination meter connector C-42 and ETACS-ECU connector C-112 are damaged, repair or replace them. Refer to Harness Connector Inspection. The "SECURITY" indicator light should illuminate, and the theft-alarm system should be armed normally.
If the connectors are in good condition, go to Step 6.
STEP 6. Check the harness wire between combination meter connector C-42 and ETACS-ECU connector C-112.
If the harness wire between combination meter connector C-42 and ETACS-ECU connector C-112 is damaged, repair it.
The "SECURITY" indicator light should illuminate, and the theft-alarm system should be armed normally.
If the harness wire is in good condition, go to Step 7.
STEP 7. Check the harness wires between combination meter connector C-42 and battery.
NOTE: After checking junction block connectors C-104 and C-109, joint connector C-78 and intermediate connector C-89, check the wires. If junction block connectors C-104 and C-109, joint connector C-78 and intermediate connector C-89 are damaged, repair or replace them. Refer to Harness Connector Inspection.
If the harness wires between combination meter C-42 and battery are damaged, repair them.
The "SECURITY" indicator light should illuminate, and the theft-alarm system should be armed normally.
STEP 8. Check the input signal.
Check the input signals from the following switches:
- Ignition key reminder switch
- Driver's and passenger's door switch
- Driver's and passenger's door lock key cylinder switch
- Driver's and passenger's door lock actuator switch
- Hood switch
- Liftgate latch switch
- Liftgate lock key cylinder switch
- Transmitter
CAUTION: To prevent damage to scan tool MB991502, always turn the ignition switch to "LOCK" (OFF) position before connecting or disconnecting scan tool MB991502.
1. Connect scan tool MB991502 to the data link connector.
2. Check that the tone alarm of scan tool MB991502 sounds when the input signal enters.
1. Use special tool MB991529 to connect a voltmeter between ground terminal 4 or 5 and ETACS-ECU terminal 9 of the data link connector.
2. Check that the voltmeter indicator deflects once when the input signal enters.
If any of the input signal checks above shows a defect, check the relevant input signal circuit.
If none of the input signal checks shows a defect, replace the ETACS-ECU.
The "SECURITY" indicator light should illuminate, and the theft-alarm system should be armed normally.