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

MODEL 219.3

Fig 1: Identifying Battery Control Unit And Ground Connection

Courtesy of MERCEDES-BENZ USA

	Remove
	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
1	Remove trunk floor covering from trunk.
2	Remove spare wheel cover or spare wheel well trim panel from trunk	Depending on equipment.
3	Switch off the ignition and remove the transmitter key from the EIS control unit	On vehicles with code (889) Keyless Go: Press Keyless-Go start/stop button repeatedly until the ignition is switched off. Remove the transmitter key from the vehicle and store at a location that is beyond the transmitter range (at least 2 m)
	Measure
4	Set multimeter to highest possible current measurement range	To protect the multimeter. When central locking is actuated, currents of approx. 20 A flow. As a result the Multimeter can be damaged by a current measurement range which is adjusted too small.
4			*WH58.30-Z-1001-09A
5	Connect positive measuring cable of multimeter to the ground connection (1) of the vehicle power supply control unit (N82)		*WH58.30-Z-1001-09A
6	Detach the negative terminal (2) from the battery (G1) and pull up carefully. Simultaneously connect the negative measuring cable of the multimeter under the negative terminal (2) to the negative terminal of the battery (G1)	Do not interrupt the circuit when detaching the negative terminal clip (2), as any faults present may be erased.
6			*WH58.30-Z-1001-09A
7	Detach the negative terminal (2) completely from the negative terminal of the battery (G1)
8	Close all doors and engine hood
9	Operate rotary tumbler in the trunk lid lock when the trunk lid is open	Pawl rotary tumbler switch in "closed" position, luggage compartment lamp goes out.
10	Lock vehicle from outside	Wait a maximum of 6 minutes after locking vehicle.
11	Check quiescent current consumption	An average value of 60 mA should not be exceeded (standard value < 40 mA).
			*WH58.30-Z-1001-09A
		Possible causes for increased values Fault cause 1: At a value of 80 mA to 180 mA a control unit does not generally switch off. However the cause may also be in an electrical or electronic component (e.g. switch). Fault cause 2: With a value of 1.2A to 2.5A; a control unit generally keeps the Controller Area Network bus class B (interior) (CAN-B) awake.
	Notes on no-load current consumption		AH54.10-P-0003-01TX
12.1	Remove the fuses in sequence and check the quiescent current consumption in each case	For cause 1
			*WH58.30-Z-1001-09A
		After each measurement insert the fuse again and then continue with the next fuse first. For installation location of fuses, see:↓
		Fuse assignment of fuse and relay box in engine compartment, left	GF54.15-P-1256-03TX
		Fuse assignment of fuse box in interior compartment on driver's side	GF54.15-P-1256-04TX
		Fuse assignment of fuse and relay box in trunk	GF54.15-P-1256-06TX
12.2	Remove the control unit fuses in sequence and check the quiescent current consumption	For cause 2
			*WH58.30-Z-1001-09A
		With the measurement, wait for 6 minutes in each case until the CAN B has come to rest mode. After each measurement insert the fuse again and then continue with the next fuse first. For installation location of fuses, see:↓
		Fuse assignment of fuse and relay box in engine compartment, left	GF54.15-P-1256-03TX
		Fuse assignment of fuse box in interior compartment on driver's side	GF54.15-P-1256-04TX
		Fuse assignment of fuse and relay box in trunk As an alternative to removing the fuses, the control units can also be separated from CAN- B. For information on the wiring diagram see:↓	GF54.15-P-1256-06TX
		Wiring diagram CAN bus interior
		CAN voltage distributor, right, X30/4	PE00.19-P-2300XA
		CAN voltage distributor, X30/7	PE00.19-P-2300XB
		CAN voltage distributor, cockpit, X30/6	PE00.19-P-2300XC
13	Mount the negative terminal (2) on the negative terminal of battery (G1). Simultaneously disconnect the negative measuring cable of the multimeter under the negative terminal (2) from the negative terminal of the battery (G1)	Do not interrupt the circuit when detaching the negative measuring cable.
13			*WH58.30-Z-1001-09A
	Install
14	Install spare wheel cover or spare wheel trim in luggage compartment	Depending on equipment.
15	Lay luggage compartment floor cover in the luggage compartment
16	Read out fault memory and erase
	Connect STAR DIAGNOSIS, read out fault memory		AD00.00-P-2000-04TX
	Connect STAR DIAGNOSIS, read out fault memory	Diagnosis system STAR DIAGNOSIS	*WH58.30-Z-1048-13A

COMMERCIALLY AVAILABLE TOOLS

Number	Designation
WH58.30-Z-1001-09A	Multimeter
WH58.30-Z-1048-13A	STAR DIAGNOSIS, diagnosis system; Compact Passenger Car	6511 1801 00