If and when371
Safety FirstOperating instructionsPractical tipsTe c h n i c a l D a t a
Starting assistance
Introduction
If the engine fails to start because of a discharged battery, the battery of
another vehicle can be used to start the engine. Before starting, check the
magic eye on the battery Ÿpage 318.
For starting assistance, jump lead cables conforming to the standard DIN
72553 are required (see the cable manufacturer instructions). The jump lead
cable must be at least 25 mm
2 in section (0.038 inches2) for petrol engines,
and 35 mm2 (0.054 inches2) for diesel engines.
For vehicles whose battery is not in the engine compartment, the jump leads
should only be connected to the starting assistance connection points in the
engine compartment.
Additional information and warnings:
xStarter assist systems (Start-Stop function) Ÿpage 221
xWorking in the engine compartment Ÿpage 304
xSelective Catalytic Reduction (AdBlue) Ÿpage 300
xVehicle battery Ÿpage 318
WARNING
Incorrect use of jump leads and incorrectly jump starting could cause the
battery to explode resulting in serious injury. Please observe the following
rules to minimise the risk of a battery explosion:
xAll work involving the vehicle battery and electrical system can cause
corrosion, fire and serious electric shocks. Always read and take into
account the safety warnings and standards before beginning work on the
battery Ÿpage 318, “Vehicle battery”.
xThe battery providing current must have the same voltage (12V) and
approximately the same capacity (see markings on battery) as the flat
battery.
xNever charge a frozen or recently thawed battery. A flat battery can
freeze at temperatures around 0°C (+32 °F).
xIf a battery is frozen and/or has been frozen then it must be replaced.
xA highly explosive mixture of gases is released when the battery is
being charged. Always keep lit cigarettes, open flames, sparks and fire far
from the battery. Never use a mobile telephone when connecting and
removing the jump leads.
xCharge the battery only in well ventilated areas given that when the
battery is charged by outside assistance, it creates a mix of highly explo-
sive gases.
xJump leads should never enter into contact with moving parts in the
engine compartment.
xNever switch the positive and negative poles or connect the jump leads
incorrectly.
xNote the instructions provided by the manufacturer of the jump leads.
Caution
To avoid considerable damage to the vehicle electrical system, note the
following carefully:
xIf the jump leads are incorrectly connected, this could result in a short
circuit.
xThe vehicles must not touch each other, otherwise electricity could flow as
soon as the positive terminals are connected.
WARNING (continued)
