Jump Starting the Engine

Do not use starting aids spray when starting the engine!


The connection sequence of the auxiliary starting battery must be observed. Otherwise there is a risk of poisoning from gases released during charging. There is also a risk of injury due to a possible explosion of the battery or damage to the vehicle's electronics.


PROCEDURE

1. The cross-section of the jump start cable for gasoline engines up to 2.5 L must be at least 16 mm2 (approximately 5 mm in diameter). For diesel engines or gasoline engines larger than 2.5 L, the cross-section must be at least 25 mm2. These data apply to a vehicle with a discharged battery. The cross-section is usually indicated on the cable packaging. It is recommended to buy a jump start cable with insulated clamps of 25 mm2 cross-section, as such a cable is suitable for smaller engines as well.
2. Both batteries must have a voltage of 12 V.
3. A discharged battery can freeze already at a temperature of -10°C. Before connecting the jump start cable, a frozen battery must be thawed.
4. The discharged battery must be connected to the vehicle's electrical system in accordance with the instructions.
5. Check the electrolyte level of the discharged battery. If necessary, top up with distilled water.
6. The vehicles must be positioned so that they do not touch each other. Otherwise, the circuit will short-circuit after the positive terminals are connected.
7. On both vehicles, apply the parking brake. Place the gear selector in neutral. For vehicles with automatic transmission, set the selector to position "P".
8. Switch off all electrical consumers.
9. The engine of the vehicle supplying the battery must run at idle speed during starting. This prevents damage to the alternator from voltage surges during starting.
10. Do not allow open flames or a lit cigarette near the battery, as flammable gases are released from the battery during charging.
11. Make sure the jump start cable is not damaged by rotating engine parts, such as the cooling fan.

PROCEDURE

1. Connect the red cable to the positive terminal in the engine compartment of the vehicle being started.

Connect the other end of the red cable to the positive terminal of the booster battery.

2. Connect the other end of the red cable to the positive terminal of the booster battery.

3. Connect the black cable to a ground point on the strut tower of the booster vehicle.

It is best to use a metal part securely connected to the engine compartment. If the vehicle is not a BMW 5 Series, connect the cable to the negative terminal of the battery.


4. Connect the other end of the black cable to a ground point on the right strut tower of the vehicle being started. If the vehicle being started is not a BMW 5 Series, connect the cable to a ground point. It is best to use a metal part threaded to the cylinder block. In unfavorable conditions, connecting the cable to the negative terminal of the discharged battery may cause a spark and release flammable gas, and the battery may explode.


* Do not allow the clamps of the jump start cable to touch each other after the cables are connected. For this reason, the positive clamps must not touch ground points (body or chassis).

5. Connection points for vehicles with the battery in the engine compartment:

1 — positive terminal (+), discharged battery (A)
2 — positive terminal (+) of the booster battery (B)
3 — negative terminal (-) of the booster battery (B)
4 — ground point (X) on the vehicle being started.

Connect the jump start cables from the auxiliary power source in the sequence shown in the illustration by the numbers (note that the cable running from the negative terminal of the booster battery is not connected to the negative terminal of the discharged battery).

Start the engine of the vehicle (discharged battery) and run it at idle. When cranking, operate the starter for no more than 10 s, as the terminals and cable may overheat due to high current consumption. Wait at least 30 s between individual start attempts.

Do not lean over the battery. Risk of poisoning!


* On BMW vehicles, before disconnecting the jump start cable, switch on the lights, rear window defroster and the highest fan speed of the heater to prevent voltage surges from the voltage regulator to the consumers.

After the engine has started, disconnect the cables in reverse order: first the black cable (-) on the vehicle being started, then on the booster vehicle. The red cable (+) is disconnected first on the booster vehicle, then on the vehicle being started.