Replacing the battery in your Mercedes-Benz W222 doesn’t require coding or resetting if you use a like-for-like replacement. This guide provides a detailed procedure for a safe and successful W222 Battery swap.
Safety Precautions
Important: Battery acid is corrosive. Wear rubber gloves, eye protection, and old clothing. Rinse any splashes with plenty of water and seek medical assistance if acid contacts your eyes.
Preparation
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Vehicle Sleep Mode: Open the car and release the bonnet. Lock the car, leaving the bonnet unlatched. Allow the vehicle to sit undisturbed for at least 30 minutes to ensure all systems enter sleep mode. Leave keys indoors or far from the car, especially if equipped with Keyless Go. This prevents accidental activation of systems during the process.
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Access the Battery: Open the bonnet and locate the battery compartment. Familiarize yourself with the layout before proceeding.
W222 Battery Removal
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Disconnect Negative Terminal: Using a suitable wrench, carefully loosen and remove the negative (black) lead from the battery terminal. Place it aside, ensuring it cannot make contact with any metal parts.
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Disconnect Positive Terminal: Repeat the process for the positive (red) lead, placing it away from the negative lead and any metal surfaces.
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Remove Retaining Clamp: Release the battery retaining clamp, which secures the battery in its tray. The mechanism may vary, so consult your owner’s manual if needed.
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Detach Overflow Pipe: If your W222 battery has a plastic overflow pipe, carefully disconnect it. Note the connection point for reattachment later.
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Lift Out Battery: Carefully lift the old battery out of the tray, keeping it upright to avoid acid spills.
W222 Battery Installation
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Clean Battery Tray: If necessary, clean the battery tray of any debris or corrosion.
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Position New Battery: Place the new W222 battery in the tray, ensuring it sits correctly and aligns with the retaining clamp.
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Secure with Clamp: Reinstall the battery retaining clamp, ensuring it firmly holds the battery in place.
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Reconnect Overflow Pipe: Attach the plastic overflow pipe to the new battery. This might involve removing a bung from the breather hole on the new battery.
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Connect Positive Terminal: Crucially, connect the positive (red) lead to the positive terminal of the new battery first. Tighten securely.
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Connect Negative Terminal: Finally, connect the negative (black) lead to the negative terminal and tighten securely.
Final Steps and System Resets
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Inspection: Double-check all connections are secure and replace any removed trim or covers.
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Startup: Retrieve your keys, unlock the car, and start the engine. The car should function normally.
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Window/Sunroof Reset: If windows or sunroof require resetting, fully open them, hold the button for 3 seconds, then close and hold the button for 3 seconds. Repeat for all affected windows/sunroof.
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Steering Reset: If a steering message appears, with the engine running, turn the steering wheel to full lock and hold for 5 seconds. Turn it to the opposite full lock and hold for 5 seconds. Repeat once more and return the steering wheel to the center.
Old Battery Disposal
Cover the terminals of the old battery and store it away from children and pets. Dispose of it properly at a designated recycling center or council tip.
