BMW X3 Service & Repair Manual: Notes/information on start assistance (jump starting)

Do not start the engine with help of starting sprays.

Preparation:

Conform with the following when starting the engine with a jump starting cable.

• Ensure that the jump starting cable wires are of appropriate cross-section size.
• Only use fuse-protected jump starting cables.
• Check whether the current-supplying battery has 12 V voltage.
• If the engine is started from the battery of another vehicle, ensure that there is no contact between the bodies of both vehicles.

IMPORTANT: Never touch electrically live ignition system components: high voltage - danger of injury!

If the battery in the vehicle supplying power is weak, start the engine of this vehicle and let it run at idling speed.

Operation: It is essential to conform to the procedures so as to avoid injury to persons or damage to parts.

• Automatic transmission: select drive position "P", apply parking brake.
• Manual transmission: move gear lever to neutral position, apply parking brake.
• Ensure that the jump leads cannot get caught in rotating parts, e.g. fan.
• First connect both positive poles of the batteries with one jump starting cable (red).
• Use the battery positive terminal in the engine compartment for vehicles with the battery in the luggage compartment.
• Then use the second jump starting cable (black) to connect the negative post of the current-supplying battery with the earth/ground point (not the negative pole or the body) of the vehicle to be started.

IMPORTANT: Do not connect the second jump starting cable (black) with the negative pole of the battery in the vehicle to be started. Produced gas could be ignited by sparks.

Risk of explosion! After the engine of the vehicle to be started has fired, first disconnect the jump starting cable between the negative pole and the earth/ground point. Then remove the starting cable from the positive poles.