Here's what BMW says:
12 00 ...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.
AND....
Jump start terminal point
The vehicle battery is installed in a relatively crash-safe area (e.g. luggage compartment). Due to the installation position, it is difficult or not possible to charge the vehicle battery or jump-start the vehicle without a special device. This is why a jump start terminal point has been provided. The jump start terminal point is installed in an easily accessible position in the engine compartment. As a result, it is possible to charge the vehicle battery or jump-start the vehicle without a special device.
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| Note!
The installation location of the jump start terminal point depends on the vehicle. The correct installation location can be called up via the hotspot on the diagnosis wiring diagram! |
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| Note!
Charge the vehicle battery via the jump start terminal points only!
If the vehicle battery is charged while it is still installed, it must be charged using the jump start terminal points. On vehicles with an intelligent battery sensor, only then can you be sure that the charging procedure is correctly detected by the vehicle electronics. If the vehicle battery is charged directly at the battery terminals, this could lead to a misinterpretation of the battery condition and even unwanted Check Control messages or fault memory entries. |
Functional description
The positive battery cable runs from the vehicle battery to the jump start terminal point.
Depending on the series and motorisation, the jump start terminal point supplies the connected consumers with terminal 30 via a protected line.
The following graphic shows an example jump start terminal point.
| Item | Explanation | Item | Explanation |
|---|
| 1 | Jump start terminal point | 2 | Fuse |
| 3 | Attachment point for the consumers (e.g. starter motor, alternator) | 4 | Attachment point of the positive battery cable |
| 5 | Conductive panel | 6 | Positive connection for battery charger or jump-start |
Structure and inner electrical connection
The jump start terminal point is designed as a conductive panel. The panel made from a copper alloy. Depending on the series and motorisation, a fuse is installed at the attachment point for the consumers.
| Item | Explanation |
|---|
| 1 | Jump start terminal point |
| 2 | Fuse (installation dependent on series and motorisation) |
| 3 | Connection for battery charger or starting aid |
Pin assignments
| Pin | Explanation |
|---|
| Terminal 30 | Voltage supply from the vehicle battery |
| U | Supply voltage for connected consumers |
Diagnosis instructions
Function check of the component
A function check of the jump start terminal point using the diagnosis system is not possible.
