Jump starting procedure Do not connect black jump lead to the negative terminal of the 12-volt battery ( - ). Connecting the negative terminal may lead to an incorrect assessment of the battery status within the vehi- cle's electronic system. Please refer to and at the start of the chapter on page 159. – Switch off the ignition in both vehicles. → page 99 – If necessary, fold open the cover on the posi- tive battery terminal (+) on the 12-volt vehicle battery in the engine compartment. → page 179 – Connect the red jump lead to the positive ter- minal of the 12-volt vehicle battery → Fig. 128 1 with the discharged vehicle bat- tery ( + ) → .
– Connect the red jump lead to the positive ter- minal of the 12-volt vehicle bat- tery → Fig. 128 2 providing assistance ( + ). Fig. 128 Schematic diagram of how to connect the Fig. 128 jump leads: – Connect black jump lead → Fig. 128 3 to a solid metal part that is securely bolted onto the cylinder block or to the cylinder block itself on the vehicle with the 12-volt vehicle battery providing assistance. 1 Vehicle with depleted 12-volt battery that accept jump starting. 2 Vehicle with a powered 12-volt battery for jump starting. – Connect the other end of the black jump lead → Fig.
128 3 to a solid metal part that is se- curely bolted onto the cylinder block or to the cylinder block itself on the vehicle with the 12- volt vehicle battery. → . 3 Suitable earth connection: e.g. bolted metal parts on the engine block or on the engine block itself. The depleted battery must be properly connected to the vehicle grid. – Position the leads in such a way that they can- not come into contact with any moving parts in the engine compartment. Make sure that there is a sufficient distance be- tween the vehicle providing jump starting assis- tance and the vehicle being jump started other- wise current could already flow when the posi- tive terminals are connected.
Starting the engine – Start the engine of the vehicle which is provid- ing assistance and let it run at idle; – Wait a few minutes and then start the engine in the vehicle with the discharged 12-volt ve- hicle battery until the engine is“running smoothly”. Ensure that the terminal clamps have good met- al-to-metal contact with the terminals. If the engine does not start immediately, switch off the starter after about 10 seconds and try again after about half a minute. Removing the jump leads – Before disconnecting the jump leads, switch off the dipped beam headlights, if switched on. Please contact an expert if the vehicle’s engine still will not start.
Connect the jump leads Only in the order A - B - C - D to connect the jumper lead. → Fig. 128 – Switch on the air conditioning blower and rear window heater in the vehicle with the dis- charged 12-volt vehicle battery. This helps minimise the voltage peaks generated when the leads are disconnected. Owner's manual 160