Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
2004 BMW 545i AutomaticFACTORY OEM SERVICE PROCEDURE
12 00 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. Refer to 12 00 ... INSTRUCTIONS FOR DISCONNECTING AND CONNECTING BATTERY .
- -> Disconnecting and connecting test equipment.
- -> Component inspection.
- -> External jump-starting aid.
- -> Compression testing. Refer to 11 00 045 CHECKING ABSOLUTE COMPRESSION OF ALL CYLINDERS .
Factory Service Tools
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.
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