Inspection Procedure C-4

TECHNICAL DESCRIPTION (COMMENT)
The door lock key cylinder switch or the ETACS-ECU may be defective.

TROUBLESHOOTING HINTS
- Malfunction of the door lock key cylinder switch
- Damaged harness wires or connectors

DIAGNOSIS
Required Special Tools:
MB991223: Test Harness Set
MB991502: Scan Tool (MUT-II)
MB991529: Diagnostic Trouble Code Check Harness

Check the input signal.
Check the input signal from the defective door lock key cylinder 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 the input signal check shows a defect, check the door lock key cylinder switch circuit. Refer to Inspection Procedure O-11.
If no defect appears, replace the ETACS-ECU.
All doors should be locked or unlocked by using the door lock key cylinder switch.