Battery — Removal and Installation (BMW 3 Series E46)

Note 1. If the ECU memory contains fault codes, they will be lost when the battery is disconnected. Therefore, before disconnecting the battery, check for codes (if you cannot do this yourself, contact your dealer or a specialized service station). If your vehicle has a theft-protected car radio, please first review the Theft-protected car radio section in the app.

Note 2: After disconnecting and reconnecting the battery, the sunroof drive initialization procedure must be performed as specified in paragraph 22 of Chapter 11.

Removal

1. The battery is located under the cover on the right side of the luggage compartment.

2. Open the trunk lid or tailgate and lift the pop.

3. On sedan and coupe models, turn the locking tabs counterclockwise 90° and partially remove the left side trim panel. On the right side of the luggage compartment, slide the trim panel and unhook the battery cover (fig. 4.3,a,b). On the touring model, press the button and release the trim under the right window. Unscrew the two nuts and remove the battery cover (fig. 4.3,c).







4. Loosen the clamp bolt of the negative battery terminal and disconnect the cable (fig. 4.4,a,b).







5. Remove the insulating boot from the positive battery terminal and disconnect the wire from the positive terminal.

6. Loosen the clamping bar bolt, unscrew the bolts and remove the clamping bar from the battery (Fig. 4.6).



7. Lift the battery and remove it from the luggage compartment. Disconnect the ventilation hose.

Installation

8. Install the battery in the reverse order. After connecting the wires to the terminals, lubricate the terminals with tips with technical petroleum jelly to protect against corrosion. First connect the positive wire, then the negative.