Check quiescent current consumption - AR54.10-P-1030MCE

MODEL 451.3/4

Fig 1: Identifying Ground Cable And Battery

Courtesy of MERCEDES-BENZ USA

	Removing
	Risk of explosion caused by escaping oxyhydrogen gas. Risk of injury caused by caustic burns to eyes, skin and mucous membranes from battery electrolyte (contains diluted sulfuric acid) or metal spatter due to short circuit. Risk of burn injuries caused by short circuit. Risk of poisoning caused by swallowing battery electrolyte (contains diluted sulfuric acid) or absorption of lead over the skin or orifices	No fire, sparks, open flames or smoking. Wear acid-resistant gloves and clothing and safety glasses with side guards. Do not place any conductive objects on the battery and avoid any short circuit from battery positive to ground. Only fill liquid battery electrolyte (diluted sulfuric acid) into suitable and appropriately marked containers.	AS54.10-Z-0001-01A
	Notes on battery		AH54.10-P-0001-01A
	Notes on AGM battery	Model 451.334/380/480	AH54.10-P-0002-01MCC
1	Connect STAR DIAGNOSIS then read-out and erase diagnostic trouble code memory		AD00.00-P-2000-04MCC
2	Close Star Diagnosis
3	Remove foot support on passenger side	Left-hand drive vehicles	AR68.30-P-1340MCC
		Right-hand drive vehicles	AR68.30-P-1340MCE
4	Measure battery voltage at battery terminals	Standard digital multimeter If the battery voltage is less than 12.2 V: ↓ Charge battery (G1)	AR54.10-P-1130MCC
5	Withdraw ignition key
6	Switch off all consumers on board the vehicle
7	Disconnect all external consumers (e.g. chargers, MP3 player, amplifier etc.)
8	Open doors and liftgate
9	Lock rotary tumblers on doors and liftgate	The interior illumination in the vehicle must go out.
10	Lock the vehicle using the central locking with open doors and liftgate	A waiting time of at least 6 mins. must be waited after locking the vehicle.
	Measure
11	Set multimeter to highest possible current measurement range	Standard digital multimeter
12	Connect multimeter between ground line (1) and negative terminal on battery (G1) without any interruption	To prevent any voltage reset, the current flow must not be interrupted. When fitting the multimeter, bridge the negative terminal of the battery (G1) beforehand.
13	Measure no-load current
14	Remove fuses one by one from the SAM control unit and localize the faulty control unit or defective consumer	If the value for the no-load current measurement: On vehicles without code (V01) Antitheft alarm system (FFO) exceeds 40 mA. On vehicles with code (V01) Antitheft alarm system (FFO) exceeds 50 mA. Wait in each case for at least 6 mins. until the next measurement to enable the activated bus to return to idle. If the fuse of the defective consumer or control unit is removed, the no-load current drops immediately. The fuse and relay assignment enables the increased no-load current consumption to be restricted to specific control units and consumers. To restrict the increased no-load current consumption yet further, the consumers and control units protected by the fuse in question must be removed one after the other. * not for USA	GF54.15-P-0800MCC
Fuse and relay box, as-built configuration * for USA only		Fuse and relay box, as-built configuration	GF54.15-P-0800MCU
15	Remove multimeter without breaking the circuit and attach ground line (1) to negative terminal
	Install
16	Install foot support on passenger side	Left-hand drive vehicles	AR68.30-P-1340MCC
		Right-hand drive vehicles	AR68.30-P-1340MCE
17	Open vehicle using central locking system
18	Unlock rotary tumblers on doors and liftgate
19	Connect STAR DIAGNOSIS then read-out and erase diagnostic trouble code memory		AD00.00-P-2000-04MCC