Disconnect/connect battery ground line - AR54.10-P-0003CW

WARNING: This page is about a different car, the 2011 Mercedes-Benz C300, 2010 Mercedes-Benz C300, 2009 Mercedes-Benz C300, and 2008 Mercedes-Benz C300. However, it is still accessible from the selected car via links, so may be relevant.

MODEL 204

Fig 1: Identifying Battery Ground Line Components

Courtesy of MERCEDES-BENZ USA

Shown on model 204.0 with engine 271

	Disconnect, connect
	Risk of explosion caused by oxyhydrogen gas. Risk of poisoning and caustic burns caused by swallowing battery acid. Risk of injury caused by burns to skin and eyes from battery acid or when handling damaged lead-acid batteries	No fire, sparks, open flames or smoking. Wear acid-resistant gloves, clothing and glasses. Only pour battery acid into suitable and appropriately marked containers.	AS54.10-Z-0001-01A
	Notes on battery		AH54.10-P-0001-01A
	Notes on AGM battery		AH54.10-P-0002-01A
1	Unclip air duct (1) (arrows) and remove	Model 204.0/2 except engine 642, 646
2	Loosen nut (2) and remove ground line (3) from negative terminal of on-board electrical system battery (G1)	Installation: Ensure that the ground line (3) is seated tightly, otherwise the electrical system may be damaged.
3	Using a diode test lamp, check the electrical system for voltage between the positive line of the on-board electrical system battery (G1) and the disconnected ground line (3)	Vehicles with code (B03) ECO start-stop function If the diode test lamp lights up, the on-board electrical system is still active because of a defect in the electrical system. In this case the ground line of the additional battery should be disconnected. See:↓
3		Remove/install additional battery Cover positive lines, there is a risk of short circuit! After this the electrical system is to be repaired upon completion of the work carried out.	AR54.10-P-0007CW
4	Connect in the reverse order.
5	Reset clock	On vehicles with code (510) Audio 20 with CD changer or with code (523) MB Audio 20 radio