Mercedes-Benz W205 Auxiliary Battery Voltage Converter

Description

Eliminate persistent dashboard warning lights, restore full interior electronic functionality, and re-activate your vehicle’s fuel-saving Eco stop-start system with this premium Mercedes-Benz W205 Auxiliary Battery Voltage Converter Module (Auxiliary Capacitor Unit). Specifically sourced and verified for the fourth-generation C-Class (W205 platform), this solid-state voltage regulation module is the definitive replacement for vehicles displaying the notorious “Auxiliary Battery Malfunction” warning on the instrument cluster display.

In the Mercedes-Benz W205 platform, the traditional physical auxiliary lead-acid battery has been replaced by this highly sophisticated Electronic Voltage Converter. This unit is a high-capacity capacitor bank housed in a compact plastic casing, typically tucked away safely beneath the passenger side footwell carpet. Its primary responsibility is to store electrical energy and step up or stabilize voltage delivery to the vehicle’s critical secondary systems—such as the electronic transmission gear selector ($ISM$), parking pawl actuators, radar safety assistance networks, and audio systems—at the exact moment the main engine restarts during an Eco stop-start cycle. Because these restarts cause a momentary voltage dip across the primary battery lines, this converter bridges the gap to prevent your dashboard, safety sensors, or radio from flickering or shutting down. Over time, internal capacitor degradation or moisture exposure under the footwell causes the internal circuit board to short out or lose its energy retention capacity. This triggers an immediate safety fault code, disables the stop-start system, and locks out various convenience features. Replacing the module completely restores electrical equilibrium.

Manufactured with premium, automotive-grade solid-state capacitors and a heat-stabilized outer polymer shell, this module is built to withstand continuous electrical cycling and cabin temperature shifts. It features the factory-correct multi-pin terminal plug layout, allowing for a direct, plug-and-play installation without requiring custom wiring modifications or expensive dealership software programming. Trust TP German Auto Spares for fully verified, workshop-tested automotive electronics, convenience modules, and relays that keep your Mercedes-Benz operating flawlessly.

Key Features:

• Vehicle Compatibility: Mercedes-Benz C-Class (W205 Platform) sedan, coupe, and estate models (C180, C200, C250, C300, C220d, C63).

• Complete Error Resolution: Directly cures the “Auxiliary Battery Malfunction” warning message and re-enables the deactivated Eco stop-start loop.

• Solid-State Reliability: Engineered with high-density internal capacitors to deliver faster charge and discharge rates than traditional backup batteries.

• Voltage Surge Protection: Integrated internal circuitry prevents electrical back-feeding, protecting delicate downstream $CAN-bus$ comfort modules.

• Direct Plug-and-Play Fitment: Exact factory-spec terminal blades ensure low electrical resistance and a secure clip-in connection to the original vehicle wiring loom.

• Condition: Rigorously bench-tested via advanced diagnostic software to verify perfect capacitance values, optimal voltage output retention, and zero internal hardware short circuits.