Inspection Procedure N-5

Theft-alarm Starter Relay Drive Circuit:

Connectors:

CIRCUIT OPERATION
When the theft-alarm system is triggered, the ETACS-ECU immobilizes the starter by energizing the theft-alarm starter relay.

TECHNICAL DESCRIPTION (COMMENT)
The theft-alarm starter relay, the key reminder switch, the ETACS-ECU or the starting system may be defective.

TROUBLESHOOTING HINTS
- Malfunction of the theft-alarm starter relay
- Malfunction of the key reminder switch
- Starting system failed
- 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 input signal.
Check the input signals from the key reminder switch.






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 a defect appears, check the key reminder switch input signal circuit. Refer to Inspection Procedure O-3.
If no defect appears, go to Step 2.







STEP 2. Check the theft-alarm starter relay.
If the theft-alarm starter relay is damaged, replace it. The engine should start.
If the theft-alarm starter relay is not damaged, go to Step 3.







STEP 3. Check the theft-alarm starter relay connector A-17X and ETACS-ECU connector C-112 for damage.
If the theft-alarm starter relay connector A-17X and ETACS-ECU connector C-112 are damaged, repair or replace them. Refer to Harness Connector Inspection.
The engine should start.
If the connectors are in good condition, go to Step 4.










STEP 4. Check the harness wires between theft-alarm starter relay connector A-17X and ETACS-ECU connector C-112.

NOTE: After checking intermediate connector C-28, check the wires. If intermediate connector C-28 is damaged, repair or replace it. Refer to Harness Connector Inspection.

If the harness wires between theft-alarm starter relay connector A-17X and ETACS-ECU connector C-112 are damaged, repair them.
The engine should start.

If the harness wires are in good condition, go to Step 5.







STEP 5. Check the theft-alarm starter relay connector A-17X and key reminder switch connector C-88 for damage.
If the theft-alarm starter relay connector A-17X and key reminder switch connector C-88 are damaged, repair or replace them. Refer to Harness Connector Inspection.
The engine should start.
If the connectors are in good condition, go to Step 6.










STEP 6. Check the harness wires between theft-alarm starter relay connector A-17X and key reminder switch connector C-88.

NOTE: After checking intermediate connector C-28, check the wires. If intermediate connector C-28 is damaged, repair or replace it. Refer to Harness Connector Inspection.

If the harness wires between theft-alarm starter relay connector A-17X and key reminder switch connector C-88 are damaged, repair them.
The engine should start.

If the harness wires are in good condition, go to Step 7.

STEP 7. Check the starting system.
Refer to Starting System - Diagnosis.
If the malfunction disappears, replace the ETACS-ECU.
The engine should start.