BMW X5 Owners & Service Manuals

BMW X5: Contents Of Engine Electrical System General

General Information


Observe safety instructions for handling vehicle battery.

Before disconnecting battery:

Turn off the ignition and other electrical loads/consumers to prevent sparking when reconnecting.

NOTE: If the ignition is not turned off when the battery is disconnected, fault memories may be set in some control units.


General notes on disconnecting battery:

After connecting battery:

IMPORTANT: After a power supply interruption some equipment is disabled and must be reactivated.

Likewise, individual settings are lost and must be activated.


Vehicles with a two-battery system

Starter and equipment batteries

A two-battery system has a starter battery circuit and an equipment battery circuit. A secondary control unit monitors both battery circuits. Depending on the situation, the battery circuits are connected to or isolated from the secondary control unit via an isolating relay.

Two AGM batteries, whose design and properties are described in AGM batteries, are used as a storage battery.

IMPORTANT: These batteries must not under any circumstances be charged with a voltage in excess of 14.8 V. Rapid programs must not be used either.

Receiving/giving starting assistance via jump start terminal The engine can be jump-started with an external voltage supply via the jump start terminal on the right side of the engine compartment.

NOTE: The starter battery is isolated from the alternators when the engine hood/bonnet is open.

Giving starting assistance via the jump start terminal is thus limited by the capacity of the starter battery when the engine hood/bonnet is open.

Charging starter and equipment batteries via jump start terminal The starter battery is charged as a matter of priority with a charger connected to the jump start terminal. The voltage at the starter battery is the decisive factor in determining whether the equipment battery is also included in the charging operation. The secondary control unit automatically detects a charging operation at a charging voltage at the starter battery of > or = 13.5 V. The isolating relay is closed and thus the equipment battery is connected in parallel. Both batteries are now charged.


If terminal 15 becomes "active" during the charging operation, the isolating relay is opened immediately and again only the starter battery is charged.

NOTE: When the engine hood is open, the isolating relay is also opened in normal operation when the engine is running.

A special mode can be set by means of diagnosis for workshop/garage operation. The isolating relay is closed from terminal R in this operating mode.

This mode is automatically reset once a distance of 5 km has been driven.

Trickle charging

The increased closed-circuit current consumption can be compensated for via the jump-start connection point with the aid of the "Acctiva easy" battery trickle charger.


 Instructions For Removing And Installing Electronic Control Units

IMPORTANT: Disconnecting the vehicle battery will cancel the fault memories of control units. Consequently, before disconnecting the car's battery, always interrogate the fault memories. Invest

 Ignition Wires, Spark Plugs

FIRING ORDER Fig. 3: Firing Order (V8) REPLACING ALL SPARK PLUGS (N62, N62TU) Special tools required: 12 1 171 12 1 172 Necessary preliminary tasks: Switch off ignition Remove all IGNITION CO

 Ignition Coil

NOTES ON CHECKING IGNITION SYSTEM Troubleshooting Fault in fuel injection system Spark plug faults Ignition coil faults Further fault patterns with evaluation Additional fault notes for troubles



CONTENTS OF ENGINE ELECTRICAL SYSTEM GENERAL General Information -> Working on ignition system. -> Removing and installing electronic control units. -> Welding work (overload protection of control units). -> Disconnecting and connecting battery. -> External jump-starting aid. INSTRUCT

 Rear Side Doors

ADJUSTING DOOR CAUTION: Do not damage adjoining body parts. Minor corrections (realignment work) are permitted if the existing adjustment options are not sufficient. NOTE: Observe gap dimensions. The door must be provided with all attachment parts for correct adjustment. Adjust screwed body parts

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