While driving my 2003 E500 MB,the service light came on for the battery,coolant, brakes, and power steering. Does all systems shut down for battery failure? Does this happen while driving?
Mercedes-Benz W211 Models are equipped with two batteries. The batteries in your w211 are an absorbed glass mat (AGM) type, which is different from the older style lead acid batteries. AGM batteries house the battery acid in glass mats. Lead acid batteries house the fluid between lead plates. AGM batteries are made of very thin glass fibers woven into a mat. This increases the surface area enough to hold sufficient electrolytes on the cells for their lifetime. Lead tends to absorb some of the acid, shortening battery life. There are positives and negatives when using AGM over lead acid batteries. For example, an AGM may charge faster, but is more susceptible to damage from overcharging. They produce less gas than a lead acid battery, can be mounted in any position (do not leak) and are safer for the environment because of this. One downside is the increased cost. Also, charging systems have evolved along with the battery type, allowing greater control of charging current via sensors and computer controlled adaptation.
The main battery in W211 models is located in the center of the trunk, mounted in a well, below the trunk carpet. The auxiliary battery is located in the right side of the engine compartment, near the HVAC intake. When replacing your battery, be sure to use a high quality unit. Replacing the battery can be done in a short amount of time. Read the battery connection notes before disconnecting the battery. Before disconnecting your battery, remove the key from the vehicle and store it in a safe place and note the radio presets. When the battery is reconnected or loses its charge, the following items may need attention (depending on vehicle equipment). You may have to reset your clock, enter the radio presets, initialize power windows, initialize the sunroof and normalize the steering angle sensor. See our tech article on battery replacing, for info on the main battery and jump-starting.
The auxiliary battery supplies power for a limited time if system charging or battery voltage drops. The battery control module monitors system voltage. If voltage reaches a low point, the auxiliary battery relay closes to connect the battery to the vehicle fuse blocks.
Remember that your car may have been serviced before and had parts replaced with different size fasteners used in the replacement. The sizes of the nuts and bolts we give may be different from what you have so be prepared with different size sockets and wrenches.
Protect your eyes, hands and body from fluids, dust and debris while working on your vehicle. If you're working with the electrical system, disconnect the battery before beginning. Always catch fluids in appropriate containers and properly dispose of any fluid waste. Recycle parts, packaging and fluids when possible. Never work on your vehicle if you feel the task is beyond your ability.
