Without Scan Tool

Check the input signal from the theft alarm system input switch, using either the scan tool or a voltmeter.




- Using a voltmeter
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. When the following switches are turned on and oft, does the voltmeter needle fluctuate? If the voltmeter needle fluctuates, the switches are normal.
- Key reminder switch
- Hood switch
- Door switch
- Door lock actuator switch
- Trunk lid latch switch
- Door lock key cylinder switch
- Trunk lid lock key cylinder switch
If the voltmeter needle does not fluctuate, the switch is faulty. Follow the symptom chart below.