Unfused Components

Special Tool
201 589 00 99 00 Electrical connecting set






Commercially available tools


1 Determine unfused components. These are e.g.
electrics in the exhaust gas recirculation (ARF) module
electrics in the airbag (AB) module
electrics in the knock control (AKR) module
electrics in the electronic ignition system (HFM/PMS/EZL) module
equipment to guard against break-in and theft, e.g. EDW and immobilizer
electrics in the idle speed control (LLR) module and alternator, starter and ignition switch

See Electric Wiring Diagrams.

Note run-on times for electronic components:
model 129 approx. 4 min

2 Read off total quiescent current on multimeter connected to battery and note value.

3 Unplug connector on possible quiescent current consumer and lace back to prevent contact if necessary.


NOTE: The quiescent current consumption may rise by approx. 0.240 A (240 mA) due to the radio. This increase in quiescent current disappears when the battery is switched on and off again.


NOTE: In vehicles with auto-pilot system (APS), an increased quiescent current consumption of approx. 800 mA occurs after insertion of the APS computer fuse for the duration of the computer boot-up procedure (approx. 30 min).

4 Read off and note total quiescent current on multimeter.

If the quiescent current drop is <=0.02A (20 mA,) or <=0.035 A (35 mA,) for immobilizer control module:
Component is in order.

5 Reconnect component.

6 Conduct test as described with all quiescent current consumers.

If the quiescent current drop is >0.02 A (20 mA) or >0.035 A (35 mA) for immobilizer control module:
Replace component.

To check results, test total quiescent current again.