VW Onboard Network Management: Documentation (Solution)

The idle speed may increase and occasionally drop, and individual electrical components may intermittently fail. In the Polo, Golf, and Touran models, when the rear window heater is turned on, this is indicated by the rear window heater indicator flashing in the instrument panel. In the Touareg, a message appears in the instrument cluster indicating "Electrical component shutdown."

Cause:
The numerous comfort features and electrical heating elements, such as seat heating, rear window heating, exterior mirror heating, and the electric auxiliary heater (heating element for auxiliary heater Z35), can overload the generator during operation, leading to battery discharge. This is especially true for extreme short-distance driving, winter driving conditions, stop-and-go traffic, and highly equipped vehicles. The onboard network control unit regularly monitors the battery voltage, taking into account the power consumption of short-term consumers. If a voltage deficit is detected in the onboard network, the control unit takes measures to maintain vehicle operation and ensure the vehicle's ability to restart.