Always use caution when working on or near the battery. NEVER allow a tool to bridge the gap between the negative and positive battery terminals. Also, be careful not to allow a tool to provide a ground between the positive cable/terminal and any metal component on the vehicle. Either of these conditions will cause a short circuit, leading to sparks and possible personal injury.
Do NOT smoke, have an open flame or create sparks near a battery; the gases contained in the battery are very explosive and, if ignited, could cause severe injury or death.
All batteries, regardless of type, should be carefully secured by a battery hold-down device. If this is not done, the battery terminals or casing may crack from stress applied to the battery during vehicle operation. A battery which is not secured may allow acid to leak out, making it discharge faster; such leaking corrosive acid can also eat away at components under the hood.
Always visually inspect the battery case for cracks, leakage and corrosion. A white corrosive substance on the battery case or on nearby components would indicate a leaking or cracked battery. If the battery is cracked, it should be replaced immediately.
On A4 and 1998-00 Passat models, in addition to the radio security code, the clock and one-touch window operation must be reset as well.
On A4 and 1998-00 Passat models, to reset the one-touch window operation:
- After connecting the negative battery cable turn the ignition switch ON, then operate each window fully closed, fully open and fully closed again and hold the window switch in the closed position for at least one full second to activate the one-touch function.