Testing quiescent current consumption - ra540d1401030x(1030)

WARNING: This page does not describe the selected car, but rather 42 other vehicles, including the 1999 Mercedes-Benz S600, 1999 Mercedes-Benz S500, 1999 Mercedes-Benz S420, 1999 Mercedes-Benz S320, and 1999 Mercedes-Benz CL600. However, it is still accessible from the selected car via links, so may be relevant.

D. Determining unfused components w/increased quiescent current consumption Model 140

Preliminary work:

Testing battery charge state.

All assemblies and components in vehicle operating properly.

Operation no. of operation texts and work units or standard texts and flat rates:

D. Determining unfused components with increased quiescent current consumption

Preliminary work:

Total quiescent current consumption tested (A).

Circuit with increased quiescent current consumption determined (B).

Unfused components	include:
	Consumers in the exhaust gas recirculation assembly (ARF) Consumers in the airbag assembly (AB) Consumers in the anti-knock control assembly (AKR) Consumers in the electronic ignition system assembly (EZL) Base module (BM) Anti-theft systems such as immobilizer Consumers in the idle speed control assembly (ISC) and generator, starter, ignition switch. See "Electric wiring diagrams" for unfused components.
Fuse for auto pilot system (when present)	remove.
Multimeter (2)	disconnect from negative pole of battery (3).
Connector or connection on possible quiescent current consumer	disconnect and tie back safe from contact (determine connector or connection in wiring diagram file "Electric wiring diagrams, passenger cars").
Multimeter (2)	connect to negative pole on battery (3) and wait approx. 4 minutes (after-running time for electronic components).
	NOTE: The quiescent current consumption can increase by approx. 0.240 A (240 mA) due to the radio. This high quiescent current consumption can be eliminated by switching the radio on and off again.
Read off quiescent current on multimeter (2) and compare with noted value	if total quiescent current drops by ≤ 0.02 A (20 mA) or ≤ 0.035 A (35 mA) on vehicles with immobilizer control module:
	Component is okay. Connect multimeter (2) to negative pole of battery (3). Reconnect connector or connection to component. Repeat test as described on all possible quiescent current consumers.
	If total quiescent current drops by >0.02 A (20 mA) or >0.035 A (35 mA) on vehicles with immobilizer control module.
	Replace component.
Check total quiescent current consumption on multimeter (2)	readout ≤ 0.05 A (50 mA) or ≤ 0.085 A (85 mA) on vehicles with immobilizer
	End of test. On vehicles with anti-theft warning system (ATA) unlock engine hood lock on right.
	Readout >0.05 A (50 mA) or >0.085 A (85 mA on vehicles with immobilizer) Perform test as described on unfused quiescent current consumers not yet tested.

COMMERCIALLY AVAILABLE TESTER

Multimeter

e. g. Sun DMM-5 e. g. Fluke, 88

Special tools

Fig 1: Identifying Special Tool (201 589 00 99 00)

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

Fig 2: Identifying Special Tool (140 589 12 21 00)

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

Fig 3: Identifying Special Tool (140 589 13 21 00)

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.