Inspection Procedure 5

Theft-alarm Starter Relay Drive Circuit:

Connectors:

CIRCUIT OPERATION
The ETACS-ECU disables the theft-alarm starter relay when the alarm operates.

TECHNICAL DESCRIPTION (COMMENT)
The theft-alarm starter relay, key reminder switch or ETACS-ECU may be faulty, or there may be a malfunction in the STARTING SYSTEM.

TROUBLESHOOTING HINTS
- Malfunction of the theft-alarm starter relay
- Malfunction of the key reminder switch
- Malfunction of STARTING SYSTEM
- Malfunction of the ETACS-ECU
- Damaged harness wires and 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
Inspect the input of the key reminder switch.






CAUTION: To prevent damage to scan tool MB991502, always turn the ignition switch to "OFF" position before connecting or disconnecting the scan tool MB991502.

1. Connect scan tool MB991502 to the data link connector.
2. Check that the tone alarm of the scan tool MB991502 sounds when the input signal.





1. Use special tool MB991529 to connect a voltmeter between grounded 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.
If there is a malfunction, inspect the key reminder switch's input circuit.

If all operations are normal, go to Step 2.

STEP 2. Check the theft-alarm starter relay.







If the theft-alarm starter relay is damaged, replace it. Confirm that the engine starts.

If the theft-alarm starter relay is not damaged, go to Step 3.







STEP 3. Check the theft-alarm starter relay connector C-109 and ETACS-ECU connector D-26 for damage.
If the theft-alarm starter relay connector C-109 and ETACS-ECU connector D-26 are damaged, repair or replace them. Refer to Harness Connector Inspection.Confirm that the engine starts.

If the connector are in good condition, go to Step 4.







STEP 4. Check the harness wire between theft-alarm starter relay connector C-109 and ETACS-ECU connector D-26.
If the harness wire between theft-alarm starter relay connector C-109 and ETACS-ECU connector D-26 is damaged, repair it. Confirm that the engine starts.

If the harness wire is in good condition, go to Step 5.







STEP 5. Check the theft-alarm starter relay connector C-109 and key reminder switch connector D-16 for damage.
If the theft-alarm starter relay connector C-109 and key reminder switch connector D-16 are damaged, repair or replace them. Refer to Harness Connector Inspection.Confirm that the engine starts.

If the connector are in good condition, go to Step 6.







STEP 6. Check the harness wire between theft-alarm starter relay connector C-109 and key reminder switch connector D-16.

NOTE: After checking intermittent connector C-72, check the wires. If intermittent connector C-72 is damaged, repair or replace it. Refer
to Harness Connector Inspection.

If the harness wire between theft-alarm starter relay connector C-109 and key reminder switch connector D-16 is damaged, repair it.Confirm that the engine starts.

If the harness wire is in good condition, go to Step 7.




STEP 7. Check the starting system.
Refer to Starting System - Diagnosis.

If the problem is not resolved, replace the ETACS-ECU.

Then, confirm that the engine starts.